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Path: bloom-beacon.mit.edu!hookup!swrinde!ihnp4.ucsd.edu!news.service.uci.edu!draco.acs.uci.edu!iglesias From: iglesias@draco.acs.uci.edu (Mike Iglesias) Newsgroups: rec.bicycles.misc,news.answers,rec.answers Subject: Rec.Bicycles Frequently Asked Questions Posting Part 3/5 Supersedes: <rec-bicycles-faq-3_940222@draco.acs.uci.edu> Followup-To: rec.bicycles.misc Date: 19 Mar 1994 17:41:35 GMT Organization: University of California, Irvine Lines: 1428 Approved: news-answers-request@MIT.Edu Distribution: world Expires: 20 Apr 94 00:00:00 GMT Message-ID: <rec-bicycles-faq-3_940319@draco.acs.uci.edu> References: <rec-bicycles-faq-1_940319@draco.acs.uci.edu> NNTP-Posting-Host: draco.acs.uci.edu Originator: iglesias@draco.acs.uci.edu Xref: bloom-beacon.mit.edu rec.bicycles.misc:14242 news.answers:16562 rec.answers:4499 Archive-name: bicycles-faq/part3 [Note: The complete FAQ is available via anonymous ftp from draco.acs.uci.edu (128.200.34.12), in pub/rec.bicycles.] --------------------------------------------------------------------------- Cracking/Breaking Cranks (Jobst Brandt jobst_brandt@hplabs.hp.com) [Ed note: Yes, another disputed issue is contained here - whether to lube the crank tapers before installing the crankarms. This has popped up from time to time on rec.bicycles, and has never been resolved one way or the other. The text here is Jobst's viewpoint.] Cranks break because they are aluminum and because they have high stress at various points. The worst of these points are at the pedal eye and where the spider fingers join the right crank. The pedal eye is a bad place because the joint is incorrectly designed, but since it is a standard, it may not be changed since it seems to work. This joint always moves and causes fretting corrosion and cracks. These cracks propagate into the crank and cause failure. A better joint here would be a 45 degree taper instead of a flat shoulder at the end of the pedal thread. The thin web between the spider and crank, another common crack origin on cranks like the Campagnolo Record, was nicely redesigned in the C-Record crank, but to make up for that the C-Record is otherwise weaker than the Record version. My experience is that they break in about 1500 miles because the pedal eye has a smaller cross section than the Record model, but maybe the alloy is poorer too. I have subsequently used Dura Ace cranks for more than two years with no failure yet. I don't believe in eternal life here either. Aluminum has no safe fatigue limit but just gets progressively safer as stress is reduced. In contrast, steel has a threshold below which failures cease. Therein lies some of the problem. As for cranks loosening, one can view the junction between spindle and crank in an exaggerated elastic model where the spindle is made of plastic and the crank of Rubbermaid household rubber. The crank, once properly installed and the retaining bolt in place, squirms on the square taper when under torque. During these deformations the crank can move only in one direction because the bolt prevents it from coming off. The crank always slides farther up the taper. Proof that the crank squirms is given by the fretting rouge always found on the spindle, whether lubricated or not, when a crank is pulled off after substantial use. As was mentioned by various observers, the left crank bolt is usually looser, after use, than the right one and this could be anticipated because the two cranks differ in their loading. This does not mean the left crank is looser. Actually it is tighter, only the bolt is looser. The left crank is more heavily loaded because it experiences offset twist from the pedal at the same time it transmits torque to the spindle. The right crank, being connected to the chain, experiences either spindle torque from the left pedal or twist from the right pedal but not torque and twist at the same time. In this squirming mode, cranks wander away from the retaining bolt and leave it loose after the first hard workout (for riders of more than 150 lbs). The bolts should NOT be re-tightened because they were correctly tight when installed. Cranks have been split in half from repeated follow-up tightening, especially left cranks. The spindle should be lubricated before installing cranks. A wipe of a mechanic's finger is adequate since this is to prevent galling in the interface. To prevent losing a loose crank bolt, the "dust" cover that is in fact the lock cap should be installed. Those who have had a crank spindle break, can attest to the greater stress on the left side because this is the end that always breaks from fatigue. A fatigue crack generally has a crystalline appearance and usually takes enough time to develop that the face of the fracture oxidizes so that only the final break is clean when inspected. Because a notch acts to concentrate stress, the advancing crack amplifies this effect and accelerates the advance once the crack has initiated. I have heard of instructions to not lubricate spindles before installing cranks but I have never been able to find it in any manufacturer's printed material. Although I have broken many Campagnolo cranks, none has ever failed at the spindle. I am certain that the standard machine practice of lubricating a taper fit has no ill effects. I have also never had a crank come loose nor have I re-tightened one once installed. --------------------------------------------------------------------------- Biopace chainrings Biopace chainrings have fallen into disfavor in recent years. They are hard to "pedal in circles". The early Biopace chainrings were designed for cadences of around 50-70 rpm, while most recommend a cadence of 80-100 rpm. Newer Biopace chainrings are less elliptical, but the general consensus is to (if you are buying a new bike) get the dealer to change the chainrings to round ones. --------------------------------------------------------------------------- Snakebite flats Snakebite flats are usually caused by the tire and tube being pinched between the road and the rim, causing two small holes in the tube that look like a snakebite. The usual causes are underinflation, too narrow a tire for your weight, or hitting something (rock, pothole) while having your full weight on the tire. The obvious solutions are to make sure your tires are inflated properly, use a larger size tire if you weigh a lot, and either avoid rocks and potholes or stand up with your knees and elbows flexed (to act like shock absorbers) when you go over them. --------------------------------------------------------------------------- Blown Tubes (Tom Reingold tr@samadams.princeton.edu) Charles E Newman writes: $ Something really weird happened at 12:11 AM. My bike blew a $ tire while just sitting parked in my room. I was awakened by a noise $ that scared the livin ^&$% out of me. I ran in and found that all the $ air was rushing out of my tire. How could something like happen in the $ middle of the night when the bike isn't even being ridden? I have $ heard of it happening when the bike is being ridden but not when it is $ parked. This happened because a bit of your inner tube was pinched between your tire bead and your rim. Sometimes it takes a while for the inner tube to creap out from under the tire. Once it does that, it has nothing to keep the air pressure in, so it blows out. Yes, it's scary. I've had it happen in the room where I was sleeping. To prevent this, inflate the tire to about 20 psi and move the tire left and right, making sure no part of the inner tube is pinched. --------------------------------------------------------------------------- Mounting Tires (Douglas Gurr dgurr@daimi.aau.dk) A request comes in for tyre mounting tricks. I suspect that this ought to be part of the FAQ list. However in lieu of this, I offer the way it was taught to me. Apologies to those for whom this is old hat, and also for the paucity of my verbal explanations. Pictures would help but, as always, the best bet is to find someone to show you. First of all, the easy bit: 1) Remove the outer tyre bead from the rim. Leave the inner bead. Handy hint. If after placing the first tyre lever you are unable to fit another in because the tension in the bead is too great then relax the first, slip the second in and use both together. 2) Pull out the tube finishing at the valve. 3) Inspect the tube, find the puncture and repair it. Now an important bit: 4) Check tyre for thorns, bits of glass etc - especially at the point where the hole in the tube was found. and now a clever bit: 5) Inflate the tube a _minimal_ amount, i.e. just sufficient for it to hold its shape. Too much inflation and it won't fit inside the tyre. Too little (including none at all) and you are likely to pinch it. More important bits: 6) Fit the tube back inside the tyre. Many people like to cover the tube in copious quantities of talcum powder first. This helps to lubricate the tyre/tube interface as is of particular importance in high pressure tyres. 7) Seat the tyre and tube over the centre of the rim. 8) Begin replacing the outer bead by hand. Start about 90 degrees away from the valve and work towards it. After you have safely passed the valve, shove it into the tyre (away from the rim) to ensure that you have not trapped the tube around the valve beneath the tyre wall. Finally the _really_ clever bit: 9) When you reach the point at which you can no longer proceed by hand, slightly _deflate_ the tube and try again. Repeat this process until either the tyre is completely on (in which case congratulations) or the tube is completely deflated. In the latter case, you will have to resort to using tyre levers and your mileage may vary. Take care. and the last important check: 10) Go round the entire wheel, pinching the tyre in with your fingers to check that there is no tube trapped beneath the rim. If you have trapped the tube, deduct ten marks and go back to step one. Otherwise .... 11) Replace wheel and reinflate. --------------------------------------------------------------------------- More Flats on Rear Tires (Jobst Brandt jobst_brandt@hplabs.hp.com) Most sharp obstacles except tetrahedral glass slivers and puncture vine gets stuck more often is that the front tire upsets the sharp object just in time for the rear tire to catch it head-on. This front to rear effect is also true for motor vehicles. Nails lying on the road seldom enter front tires. When dropped on the road by a moving vehicle, the nail slides down the road aligning itself pointing toward traffic because it tends to roll around until it is head first. The tire rolls over it and tilts it up so that if the speed is ideal, the rear tire catches it upright. I once got a flat from a one inch diameter steel washer that the rear tire struck on edge after the front tire flipped it up. When it is wet glass can stick to the tire even in the flat orientation and thereby get a second chance when it comes around again. To add to this feature, glass cuts far more easily when wet as those who have cut rubber tubing in chemistry class may remember. A wet razor blade cuts latex rubber tubing in a single slice while a dry blade only makes a nick. --------------------------------------------------------------------------- What holds the rim off the ground? (Jobst Brandt jobst_brandt@hplabs.hp.com) > What forces keep the rim of a wheel with pneumatic tires off the > ground. It obviously can't be the air pressure because that's acting > from top as well as from below. As has been pointed out, the casing walls pull on the rim (or its equivalent) and thereby support the load. The casing leaves the rim at about a 45 degree angle, and being essentially a circular cross section, it is in contact with the rim over its inner quarter circle. At least this is a good representative model. The visualization may be simpler if a tubular tire is considered. It makes no difference whether the tire is held on by glue or is otherwise attaches to the rim such as a clincher is. Either way the tire is attached to the rim, a relatively rigid structure. Under load, in the ground contact zone, the tire bulges so that two effects reduce the downward pull (increase the net upward force) of the casing. First, the most obvious one is that the casing pulls more to the sides than downward (than it did in its unloaded condition); the second is that the side wall tension is reduced. The reduction arises from the relationship that unit casing tension is equivalent to inflation pressure times the radius of curvature divided by pi. As the curvature reduces when the tire bulges out, the casing tension decreases correspondingly. The inflated tire supports the rim primarily by these two effects. Tire pressure changes imperceptibly when the tire is loaded because the volume does not change appreciably. Besides, the volume change is insignificant in small in comparison to the volume change the air has undergone when being compressed into the tire. In that respect, it takes several strokes of a frame pump to increase the pressure of a tire from 100 psi to 101. The air has a low spring constant that acts like a long soft spring that has been preloaded over a long stroke. Small deflections do not change its force materially. For convenience car and truck tires are regularly inflated to their proper pressure before being mounted on the vehicle. --------------------------------------------------------------------------- Anodized vs. Non-anodized Rims (Jobst Brandt jobst_brandt@hplabs.hp.com) There are several kinds of dark coatings sold on rims. Each suggests that added strength is achieved by this surface treatment while in fact no useful effects other than aesthetic results are achieved. The colored rims just cost more as do the cosmetically anodized ones. The hard anodized rims do not get stronger even though they have a hard crust. The anodized crust is brittle and porous and crazes around spoke holes when the sockets are riveted into the rim. These cracks grow and ultimately cause break-outs if the wheel is subjected to moderate loads over time. There is substantial data on this and shops like Wheelsmith, that build many wheels, can tell you that for instance, no MA-2 rims have cracked while MA-40 rims fail often. These are otherwise identical rims. Hard anodizing is also a thermal and electrical insulator. Because heat is generated in the brake pads and not the rim, braking energy must cross the interface to be dissipated in the rim. Anodizing, although relatively thin, impedes this heat transfer and reduces braking efficiency by overheating the brake pad surfaces. Fortunately, in wet weather, road grit wears off the sidewall anodizing and leaves a messy looking rim with better braking. Anodizing has nothing to do with heat treatment and does not strengthen rims. To make up for that, it costs more. --------------------------------------------------------------------------- Reusing Spokes (Jobst Brandt jobst_brandt@hplabs.hp.com) >I just bent my wheel and am probably going to need a new one >built. Can I reuse my old, 3 months, spokes in the new wheel. >The guy at the shop gave me some mumbo jumbo about tensioning or >something. There is no reason why you should not reuse the spokes of your relatively new wheel. The reason a bike shop would not choose to do this is that they do not know the history of your spokes and do not want to risk their work on unknown materials. If you are satisfied that the spokes are good quality you should definitely use them for you new wheel. The spokes should, however, not be removed from the hub because they have all taken a set peculiar to their location, be that inside or outside spokes. The elbows of outside spokes, for instance, have an acute angle while the inside spokes are obtuse. There are a few restrictions to this method, such as that new rim must have the same effective diameter as the old, or the spokes will be the wrong length. The rim should also be the same "handedness" so that the rim holes are offset in the correct direction. This is not a fatal problem because you can advance the rim one hole so that there is a match. The only problem is that the stem will not fall between parallel spokes as it should for pumping convenience. Take a cotton swab and dab a little oil in each spoke socket of the new rim before you begin. Hold the rims side by side so that the stem holes are aligned and note whether the rim holes are staggered in the same way. If not line the rim up so they are. Then unscrew one spoke at a time, put a wipe of oil on the threads and engage it in the new rim. When they are all in the new rim you proceed as you would truing any wheel. Details of this are in a good book on building wheels. The reason you can reuse spokes is that their failure mode is fatigue. There is no other way of causing a fatigue failure than to ride many thousand miles (if your wheel is properly built). A crash does not induce fatigue nor does it even raise tension in spokes unless you get a pedal between them. Unless a spoke has a kink that cannot be straightened by hand, they can all be reused. --------------------------------------------------------------------------- Clinchers vs. Tubulars (F.J. Brown F.Brown@massey.ac.nz) D.H.Davis@gdt.bath.ac.uk gave some useful hints on mounting clinchers, mostly involving the use of copious quantities of baby powder, and trying to convince me that clinchers aren't difficult to mount, so ease of mounting isn't a valid reason for preferring tubulars. wernerj@lafcol.lafayette.edu wrote that although average tubulars ride 'nicer' than average clinchers, there are some clinchers around that ride just as 'nice'. He also said that ease of change isn't a good reason for preferring tubulars as if you flat in a race, you're either going to swap a wheel or drop out. He pointed out that tubulars end up costing $20 - $80 per flat. ershc@cunyvm.cuny.edu gave some of the historic reasons that tubulars were preferred: higher pressures, lower weight, stronger, lighter rims. Said that only a few of these still hold true (rim strength/weight, total weight), but he still prefers the 'feel' of tubulars. leka@uhifa.ifa.hawaii.edu started this thread with his observations on clinchers seperated from their rims in the aftermath of a race crash. stek@alcvax.pfc.mit.edu comments on improperly-glued tubulars posing a threat to other racers by rolling off, and noted that this couldn't happen with clinchers. jobst_brandt@hplabs.hp.com agreed with stek, with the additional note that it is inadequate inflation that often allows tubulars to roll. Kevin at Buffalo agreed with stek and jobst about tubulars (improperly or freshly glued) sometimes rolling. ruhtra@turing.toronto.edu says he uses clinchers for cost and convenience. Clinchers let him carry around a tiny patch kit and some tyre irons, costing 60c, whereas tubulars would require him to carry a whole tyre, and would cost more. CONCLUSIONS: THE CLINCHER VS. TUBULAR WAR Tubulars - used to be capable of taking higher pressures, had lower weight and mounted onto stronger, lighter rims than clinchers. Clinchers have now largely caught up, but many cyclists thinking hasn't. Tubular tyre + rim combination still lighter and stronger. - are easier to change than clinchers. This matters more to some people than others - triathletes, mechanical morons and those riding in unsupported races. - cost megabucks if you replace them every time you puncture. ***However*** (and none of the North Americans mentioned this) down here in Kiwiland, we ***always*** repair our punctured tubulars (unless the casing is cut to ribbons). The process doesn't take much imagination, you just unstitch the case, repair the tube in the normal manner using the thinnest patches you can buy, stitch it back up again and (the secret to success) put a drop of Superglue over the hole in the tread. - can roll off if improperly glued or inflated. In this case, you probably deserve what you get. Unfortunately, the riders behind you don't. Clinchers - can be difficult to change (for mechanical morons) and are always slower to change than tubulars. Most people still carry a spare tube and do their repairs when they get home. - are cheaper to run: if you puncture a lot clinchers will probably still save you money over tubulars, even if you repair your tubulars whenever possible. Tubulars are only repairable most of the time, you virtually never write off a clincher casing due to a puncture. - have improved immensely in recent years; top models now inflate to high pressures, and are lighter and stronger than they used to be. Likewise clincher rims. Some debate over whether tubulars are still lighter and tubular rims stronger. Probably depends on quality you select. No doubt that high quality clinchers/rims stronger, lighter and mor dependable than cheap tubular/rim combination. --------------------------------------------------------------------------- Presta Valve Nuts (Jobst Brandt jobst_brandt@hplabs.hp.com) Two points here: 1. The jamb nut holds the stem when pumping so that it does not recede into the rim when pressing the pump head against the tire. This is especially useful when the tire is flat (after installing the tube). It also keeps the stem from wiggling around while pumping. Removing the nut should present no difficulty unless the threads have been damaged or the hands are cold. The cold may present a problem, but then just opening the valve nut on a Presta valve under such conditions. 2. Breaking off stems with a frame pump comes from pumping incorrectly. The number of new tubes with broken stems lying along the road proves that this occurs far too often. To avoid breaking the stem, the pump head should be be held in the fist so that the pumping force goes from one hand into the other, not from the pump into the valve stem. To practice the correct action, hold the pump head in one hand with the thumb over the outlet, and pump vigorously letting out no air. All the force goes from one hand into the other. This is essentially what should take place when inflating a tire. It does no good to "get even" with the stupid tube by discarding it on the road for all to see. Most riders understand how to pump a tire and see this only as evidence of incompetence rather than a faulty tube. Besides, this ostentatious behavior constitutes littering for which the the fine is $1000 in California. Bike shops should instruct new bike owners about the use of the frame pump. Along with this there should be some tire patch hints like don't try to ride a freshly patched tube, carry a spare tube and always use the spare after patching the punctured tube. Of course this is a whole subject in itself that should be treated under its own heading. --------------------------------------------------------------------------- Ideal Tire Sizes (Jobst Brandt jobst_brandt@hplabs.hp.com) > I'm getting a custom frame built and wondered what > people thought of using 26 inch road wheels. Smaller > wheels ought to be lighter and stronger. and goes on to list advantages and disadvantages, most of which are less that important in deciding what size to use. What in fact brought us the wheel size (700 or 27") that we have is better understood by the women riders who have a hard time fitting these wheels into their small bicycle frames. Wheels would be larger than they are if they would fit the average riders bike, but they don't. So the compromise size is what we are riding today. > It seems to me that the most obvious reason for using 27" > wheels is tradition, but I'm not sure the advantages make > it worth trying to swim upstream. What do you think? This line of thought is consistent with the "cost be damned" approach in bicycling today. The big bucks are spent by people who want the best or even better than their peers. The more special the better. Riders consistently spend nearly twice the money for wheels and get worse rims when they choose anodized ones, whether there is merit to this finish is of no interest. They cost more so they must be better. How "custom" can you get than to have wheels no one else on the block has (maybe 25"?). If enough riders ask for 24", 25" and 26" wheels, manufacturers will up the price as their product lines multiply and the total sales remain constant. Tires and spokes will follow as a whole range of sizes that were not previously stocked become part of the inventory. Meanwhile, bike frames will come in different configurations to take advantage of the special wheel sizes. SIzes whose advantages are imperceptibly small but are touted by riders who talk of seconds saved in their last club TT or while riding to work. A larger wheel rides better on average roads and always corners better because it brings a longer contact patch to the road. A longer contact averages traction over more pavement and avoids slip outs for lack of local traction. Visualize crossing a one inch wide glossy paint stripe with a 27" wheel and an 18" wheel when banked over in a wet turn. I see this subject arise now and then and it reminds me of the concept of splitting wreck.bike into several newsgroups. The perpetrators bring the matter up for many of the wrong reasons. Ride bike, don't re-invent what has been discarded. --------------------------------------------------------------------------- Indexed Steering (Jobst Brandt jobst_brandt@hplabs.hp.com) > In the several years I spent working in a pro shop, I have never seen a > case of "index steering" (yes, we called it that) that was _not_ caused > by a "brinelled" headset - one with divots in the races. I am 99.999 > percent certain that that is your problem. What are you going to do if > you don't fix it? I suggest that you fix the headset even if you sell > the bike, as a damaged headset could be grounds for a lawsuit if the > buyer crashes. I disagree on two points. First, because the use of the term brinelling conveys a notion as incorrect as the phrase "my chain stretched from climbing steep hills" and second, because there is no possibility of injury or damage from an "indexed" head bearing. Damage to the head bearings seems to be twofold in this case because the steering, if properly adjusted, only gets looser from dimpled bearings and would not become arrested by the dimples. So the head was adjusted too tight or it got tighter inadvertently. However, dimpling is caused by lubrication failure and occurs while riding straight ahead. This condition is worsened by a tight bearing while a loose bearing would introduce more lubricant if it were to rattle. If you believe it comes from hammering the balls into the races, I suggest you try to cause some dimples by hammering with a hammer onto the underside of the fork crown of a clunker bike of your choice. Those who pounded in cotters on cottered cranks will recall no such dimpling on the BB axle and even though this is a far smaller bearing race than a head bearing and the blows are more severe and direct, no dimples were made. Ball bearings make metal-to-metal contact only when subjected to fretting loads (microscopic oscillations) while in the same position, as in riding straight ahead on a conventional road. If you watch your front axle while rolling down the road at 20+ mph you will notice that the fork ends vibrate fore and aft. This motion arises not at the blade tips but at the fork crown and articulates the head bearing in fretting motions that are not in the normal direction of bearing rotation. Any substantial steering motion replenishes lubrication from adjoining areas. Lubrication failure from fretting causes welding between the balls and races and these tiny weld spots tear out repeatedly. The result is that at the front and rear of the races elliptical milky dimples occur. Were these brinelling (embossed through force) they would be shiny and round. Various testimonials for the durability of one bearing over another may be based on good experience, however, the differences in most of these was not in the design of the bearing but rather the type of lubricant used. A ball bearing is not suitable for this use. This is in spite of their use in almost all bicycles. To reduce point loads and to protect the rolling elements from fretting motion, roller bearing head bearings have been built. In these the rotary motion is taken up in needle bearings on conical races and the fork articulation is absorbed by an approximation of a spherical cup (the steel race) against the aluminum housing. Both of these bearings are ideally loaded. The rollers all remain in contact and carry rotary motion while the plain spherical bearing remains in full contact carrying low pressure fore and aft motion. I am disappointed that roller bearings until now have not been suitably perfected to rid us of the age old bearing failure. Maybe some day soon Sun Tour, Campagnolo, Shimano or Stronglight will emerge with an easily adjustable and fully compatible bearing. The one I am using is durable but not easily adjusted and it has too great a stack height to qualify for a recommended replacement. --------------------------------------------------------------------------- Center Pivot vs. Dual Pivot Brakes (Jobst Brandt jobst_brandt@hplabs.hp.com) Sidepull (one central pivot) brakes operate at a small angle to the rim. That means the pad moves in a nearly perpendicular direction to the braking surface and the pads can be completely worn down without adjusting their position. The unit is light and has a self contained quick release and cable adjustment feature. Its weakness is its thin arms that, in the pursuit of light weight, flex in the bending direction. With the current practice to minimize tire clearance on road bicycles, sidepull brakes cannot be used off road for lack of dirt clearance. Their return spring is anchored in a way that relative motion occurs between it and the brake arms. This motion demands lubrication and in its absence the brake does not center itself. This is a perpetual problem that has not been solved and has given rise to many designs, the latest of which is the Shimano dual pivot brake. This brake has the disadvantage that it cannot track a wobbly wheel because it is forced to be centered. The cantilever and centerpull brakes are inversions of the same design. Both have pivot points that are at 45 degrees to the brake surface, but the centerpull offers no advantage over sidepulls because it has all the same problems and not the advantages. In contrast the cantilever is the most rigid of available brakes and offers more tire clearance for off road use. The approach angel moves the brake pads in an undesirable direction so that as the pad wears it must be adjusted to prevent falling off the rim. With wear, the centerpull goes into the tire while the cantilever allows the pad to pop under the rim, never to return. Cantilever brakes have the additional problem that their reaction force spreads the forks. For this reason, U shaped stress plates are made to contain this force. For forks with telescopic suspension, braking restricts forks motion. Nearly all bicycle brakes have about the same mechanical advantage (4:1) that arises primarily in the hand lever. The "calipers" all approximate a 1:1 ratio. This is necessary to fit the reach of the average hand and the strength of the hand in proportion to body weight. That is to say all brakes are made to about the same human specification. Force and motion are a trade-off and this is the result. The Campagnolo Delta and Modolo Chronos brakes have a variable ratio that at the extremes ranges from infinity to zero, its motion being generated by an equilateral parallelogram that changes from one extreme to the other. This is an undesirable feature, especially as the pads wear and braking takes place in the zone of increased lever travel and increased mechanical advantage. The brake bottoms out abruptly. Servo activation on cantilever brakes has been offered in a design that uses the forward thrust on the brake post to add force to the application. Self servo effects are undesirable in brakes because the proportionality between braking and hand force is lost. You don't know how much braking you will get for a given hand lever force. It can vary widely and in some circumstances cause an unwanted skid. --------------------------------------------------------------------------- Seat adjustments (Roger Marquis marquis@well.sf.ca.us) The following method of setting saddle height is not the only method around for setting your saddle height but it is the most popular among coaches and riders both here and in Europe. A) Adjust saddle level or very slightly nose up, no more than 2mm at the nose. B) Put on the shoes you normally ride in. Have wrench ready (usually a 5mm Allen). C) Mount the bike and sit comfortably, leaning against a wall. Hold the brake on with one hand (or mount the bike on a turbo trainer if you have one). D) Place your HEELS on the pedals, opposite the clip, pedal backwards at 30+ rpm without rocking your pelvis (very important). E) Adjust seat height so that there is about: 1) ZERO TO ONE HALF CM. for recreational riders (-50 mi/wk.), 2) ONE HALF TO ONE CM. for experienced riders (50+ mi./wk.), 3) ONE TO TWO CM. for endurance cyclists (250+ mi./wk.), between your heel and the pedal. If your soles are thicker at the cleat than at the heel adjust accordingly. Don't forget to grease the seat post. F) Ride. It may take a couple of rides to get used to the feel and possibly stretch the hamstrings and Achilles slightly. --------------------------------------------------------------------------- Cleat adjustments (Roger Marquis marquis@well.sf.ca.us) [Ed note: You may also want to consider going to a bike shop that does Fit Kit and have them do the Fit Kit RAD to adjust your cleats. Many people recommend it.] A) Grease the cleat bolts and lightly tighten. B) Sitting on the bike, put your feet in the pedals and adjust until: B1) The ball of your foot is directly above or, more commonly, slightly behind the pedal axle and: B2) There is approximately 1 cm. (1/2in.) between your ankle and the crank arm. C) Tighten the cleat bolts 80% and go out for a ride. If another position feels more comfortable rotate your foot into that position. D) Carefully remove your shoes from the pedals and tighten the bolts fully. If you cannot get out of the pedals without shifting the cleats leave your shoes on the bike and draw an outline around the cleat. --------------------------------------------------------------------------- SIS Adjustment Procedure (Bob Fishell spike@cbnewsd.att.com) Shimano's instructions for adjusting SIS drivetrains varies from series to series. The following method, however, works for each of mine (600EX, 105, and Deore'). [Ed note: Works on Exage road and mtb also.] Your chain and cogs must be in good shape, and the cable must be free of kinks, slips, and binds. The outer cable should have a liner. clean and lubricate all points where the cable contacts anything. SIS adjustment: 1) Shift the chain onto the largest chainwheel and the smallest cog, e.g., 52 and 13. 2) WITHOUT TURNING THE CRANKS, move the shift lever back until it clicks, and LET GO. This is the trick to adjusting SIS. 3) Turn the crank. If the chain does not move crisply onto the next inside cog, shift it back where you started, turn the SIS barrel adjuster (on the back of the rear derailleur) one-half turn CCW, and go back to step 2. Repeat for each pair of cogs in turn until you can downshift through the entire range of the large chainwheel gears without the chain hesitating. If you have just installed or reinstalled a shift cable, you may need to do this several times. 4) Move the chain to the small chainring (middle on a triple) and the largest cog. 5) turn the cranks and upshift. If the chain does not move crisply from the first to the second cog, turn the SIS barrel adjuster one-quarter turn CW. If the drivetrain cannot be tuned to noiseless and trouble-free SIS operation by this method, you may have worn cogs, worn chain, or a worn, damaged, or obstructed shift cable. Replace as needed and repeat the adjustment. --------------------------------------------------------------------------- Where to buy tools You can buy tools from many sources. Some tools can be purchased at your local hardware store (wrenches, socket sets, etc), while the special bike tools can be purchased from your local bike store or one of the mail order stores listed elsewhere. You can buy every tool you think looks useful, or just buy the tools you need for a particular repair job. Buying the tools as you need them will let you build up a nice tool set over time without having to drop a lot of money at once. Some common tools you will need are: Metric/SAE wrenches for nuts and bolts (or an assortment of adjustable wrenches). Screwdrivers, both flat and phillips. Metric allen wrenches. Pliers. Wood or rubber mallet for loosening bolts. Special tools and their uses: Cone wrenches to adjust the hub cones. Chain tool to take the chain apart for cleaning and lubrication, and to put it back together. Tire irons for removing tires. Spoke wrenches for adjusting spokes. Cable cutters for cutting cables (don't use diagonal pliers!). Crankarm tools for removing crankarms. Bottom bracket tools for adjusting bottom brackets. Headset wrenches to adjust the large headset nut. --------------------------------------------------------------------------- Workstands There are a variety of workstands available, from about $30 to over $130. Look at the mail order catalogs for photos showing the different types. The type with a clamp that holds one of the tubes on the bike are the nicest and easy to use. Park has a couple of models, and their clamp is the lever type (pull the lever to lock the clamp). Blackburn and Performance have the screw type clamp (screw the clamp shut on the tube. If you have a low budget, you can use two pieces of rope hanging from the ceiling with rubber coated hooks on the end - just hang the bike by the top tube. This is not as steady as a workstand, but will do an adequate job. --------------------------------------------------------------------------- Workstands 2 (Douglas B. Meade meade@bigcheese.math.scarolina.edu) >>>>>>>>>> BICYCLE REPAIR STAND SUMMARY <<<<<<<<<< The Park PRS6 was recommended by several (>5) responders; all other models were recommended by no more than one responder. Park PRS6 PROS: full 360\degree rotation spring-loaded clamp is adjustable very stable CONS: not height adjustable not easy to transport clamp probably can't work with fat-tubed mtn bike COST: ~$150 SOURCE: catalogs, local bike shops Park Consumer PROS: foldable convenient portable CONS: not as stable as PRS6 COST: ~$100 SOURCE: catalogs, local bike shops Park BenchMount PROS: stronger, and more stable, than many floor models CONS: must have a workbench with room to mount the stand COST: $??? SOURCE: ??? Blackburn PROS: The stand folds flat and is portable. It has a 360 degree rotating clamp. It is relatively stable. CONS: crank-down clamp does not seem to be durable crank bolt is not standard size; difficult to replace hard to get clamp tight enough for stable use clamp scratchs paint/finish problems getting rotating mechanism to work properly COST: ~$100 SOURCE: catalogs, local bike shops Performance PROS: CONS: not too stable Ultimate Repair Stand PROS: excellent quality includes truing stand includes carrying bag CONS: COST: ~$225 SOURCE: order through local bike shop the U.S. address for Ultimate Support Systems is : Ultimate Support Systems 2506 Zurich Dr. P.O. Box 470 Fort Collins, CO. 80522-4700 Phone (303) 493-4488 I also received three homemade designs. The first is quite simple: hang the bike from coated screw hooks (available in a hardware store for less that $5/pair) The others are more sophisticated. Here are the descriptions provided by the designers of the systems. Dan Dixon <djd@hpfcla.fc.hp.com> describes a modification of the Yakima Quickstand attachment into a freestanding workstand I picked up the Yakama clamp and my local Bike shop for around $25. What you get is the clamp and a long carraige bolt with a big (5") wing nut. This is meant to be attached to their floor stand or their roof racks. The roof rack attachment is ~$60; expensive, but great for road trips. I, instead, bought a longer carraige bolt, a piece of 3/4" threaded lead pipe, two floor flanges, and some 2x4's. (about $10 worth of stuff). You say you want to attach it to a bench (which should be easy) pipe +- clamp | wing nut | | | V | +--+ V | |---------+ V | | O | | | |\_________/| | | / | | -O- |=| _________ |=| |==I | | | |/ \| | | \ | |---------+ | | O | | /\ /\ | |<-2x4 | | | | flanges--+---------+ | | | | Excuse the artwork, but it might give you and Idea about what I mean. You could just nail the 2x4 to the bench or something. I really like the clamp because it is totally adjustable for different size tubes. Eric Schweitzer <ERSHC@cunyvm.cuny.edu> prefers the following set-up to the Park `Professional' stands that he also has. My favorite 'stand', one I used for many years, one that I would use now if my choice of stand were mine, is made very cheaply from old seats and bicycle chain. Two seats (preferably cheap plastic shelled seats) (oh...they must have one wire bent around at the front to form the seat rails...most seats do) have the rails removed and bent to form 'hooks'. The 'right' kind of hooks are placed in a good spot on the ceiling about 5 or 6 feet apart. (really, a bit longer than the length of a 'typical' bike from hub to hub. If you do a lot of tandems or LWB recombants, try longer :) Form a loop in one end of the chain by passing a thin bolt through the opening between 'outer' plates in two spots on the chain. (of course, this forms a loop in the chain, not the bolt). The same is done at the other end to form loops to hold the seat rail/hooks. First, form the hooks so they form a pair of Js, about 2 inch 'hook's The hook for the front of the bike is padded, the one for the rear looped through the chain, squeezed together to a single hook, and padded. To use, hook the rear hook under the seat, or at the seat stays. Hook the front with each arm on oposite sides of the stem. Can also hook to head tube (when doing forks). Either hook can grab a rim to hold a wheel in place while tightening a quick release skewer or axle bolt. There is no restricted access to the left side of the bike. I try to get the BB of a 'typical' frame about waist height. In closing, here is a general statement that only makes my decision more difficult: My best advice is to consider a workstand a long term durable good. Spend the money for solid construction. Good stands don't wear or break, and will always be good stands until the day you die, at which point they will be good stands for your children. Cheese will always be cheese until it breaks. --------------------------------------------------------------------------- Frame Stiffness (Bob Bundy bobb@ico.isc.com) As many of you rec.bicycles readers are aware, there have been occasional, sometimes acrimonious, discussions about how some frames are so much stiffer than others. Cannondale frames seem to take most of the abuse. The litany of complaints about some bike frames is long and includes excessive wheel hop, numb hands, unpleasant ride, broken spokes, pitted headsets, etc. I was complaining to a friend of mine about how there was so much ranting and raving but so little empirical data - to which he replied, "Why don't you stop complaining and do the measurements yourself?". To that, I emitted the fateful words, "Why not, after all, how hard can it be?". Following some consultation with Jobst and a few other friends, I ran the following tests: The following data were collected by measuring the vertical deflection at the seat (ST), bottom bracket (BB) and head tube (HT) as a result of applying 80lb of vertical force. The relative contributions of the tires, wheels, fork, and frame (the diamond portion) were measured using a set of jigs and a dial indicator which was read to the nearest .001 inch. For some of the measures, I applied pressures from 20 to 270 lbs to check for any significant nonlinearity. None was observed. The same set of tires (Continentals) and wheels were used for all measurements. Note that these were measures of in-plane stiffness, which should be related to ride comfort, and not tortional stiffness which is something else entirely. Bikes: TA - 1987 Trek Aluminum 1200, this model has a Vitus front fork, most reviews describe this as being an exceptionally smooth riding bike SS - 1988 Specialized Sirus, steel CrMo frame, described by one review as being stiff, hard riding and responsive DR - 1987 DeRosa, SP/SL tubing, classic Italian road bike RM - 1988 Cannondale aluminum frame with a CrMo fork, some reviewers could not tolerate the rough ride of this bike TA SS DR RM ---------- ---------- ---------- ---------- ST BB HT ST BB HT ST BB HS ST BB HT diamond 1 1 0 2 2 0 2 2 0 1 1 0 fork 3 11 45 3 9 36 4 13 55 3 10 40 wheels 2 2 2 2 2 2 2 2 2 2 2 2 tires 68 52 66 68 52 66 68 52 66 68 52 66 total 74 66 113 75 65 104 76 69 123 74 65 108 What is going on here? I read the bike mags and this net enough to know that people have strong impressions about the things that affect ride comfort. For example, it is common to hear people talk about rim types (aero vs. non-aero), spoke size, butting and spoke patterns and how they affect ride. Yet the data presented here indicate, just a Jobst predicted, that any variation in these factors will essentially be undetectable to the rider. Similarly, one hears the same kind of talk about frames, namely, that frame material X gives a better ride than frame material Y, that butted tubing gives a better ride that non-butted, etc. (I may have even made such statements myself at some time.) Yet, again, the data suggest that these differences are small and, perhaps, even undetectable. I offer two explanations for this variation between the data and subjective reports of ride quality. Engineering: These data are all static measurements and perhaps only applicable at the end of the frequency spectrum. Factors such as frequency response, and damping might be significant factors in rider comfort. Psychology: There is no doubt that these bikes all look very different, especially the Cannondale. They even sound different while riding over rough roads. These factors, along with the impressions of friends and reviews in bike magazines may lead us to perceive differences where they, in fact, do not exist. Being a psychologist, I am naturally inclined toward the psychological explanation. I just can't see how the diamond part of the frame contributes in any significant way to the comfort of a bike. The damping of the frame should be irrelevant since it doesn't flex enough that there is any motion to actually dampen. That the frame would become flexible at some important range of the frequency spectrum doesn't seem likely either. On the other hand, there is plenty of evidence that people are often very poor judges of their physical environment. They often see relationships where they don't exist and mis-attribute other relationships. For example, peoples' judgement of ride quality in automobiles is more related to the sounds inside the automobile than the ride itself. The only way to get a good correlation between accelerometers attached to the car seat and the rider's estimates of ride quality is to blindfold and deafen the rider (not permanently!). This is only one of many examples of mis- attribution. The role of expectation is even more powerful. (Some even claim that whole areas of medicine are built around it - but that is another story entirely.) People hear that Cannondales are stiff and, let's face it, they certainly *look* stiff. Add to that the fact that Cannondales sound different while going over rough roads and perhaps the rider has an auditory confirmation of what is already believed to be true. Unless anyone can come up with a better explanation, I will remain convinced that differences in ride quality among frames are more a matter of perception than of actual physical differences. --------------------------------------------------------------------------- Frame materials [Ed note: I got this information from some of the books I have. People in the know are welcome to update this.] There are several materials that are used to make bicycle frames. They are: Mild steel - usually used in cheap department store bikes. Frames made from mild steel are heavy. High carbon steel - a higher quality material used in low end bikes. Reynolds 500 is an example. Steel alloy - lighter and better riding than high-carbon frames. Reynolds 501 and Tange Mangaloy are examples. Chro-moly - also called chrome-molybdenum or manganese-molybdenum steel. One of the finest alloys for bike frames. Reynolds 531 and Columbus SL and SP are some of the best known brands. Carbon fiber - high tech stuff. Made from space-age materials, frames made of this are very light and strong. Some problems have been seen in the connections between the tubes and bottom bracket, etc. Aluminum - Light frames, usually with larger diameter tubes. Cannondale is a well-known brand. --------------------------------------------------------------------------- Bike pulls to one side (Jobst Brandt jobst_brandt@hplabs.hp.com) For less than million dollar bikes this is easy to fix, whether it corrects the cause or not. If a bike veers to one side when ridden no-hands, it can be corrected by bending the forks to the same side as you must lean to ride straight. This is done by bending the fork blades one at a time, about 3 mm. If more correction is needed, repeat the exercise. The problem is usually in the forks although it is possible for frame misalignment to cause this effect. The kind of frame alignment error that causes this is a head and seat tube not in the same plane. This is not easily measured other than by sighting or on a plane table. The trouble with forks is that they are more difficult to measure even though shops will not admit it. It takes good fixturing to align a fork because a short fork blade can escape detection by most measurement methods. Meanwhile lateral and in-line corrections may seem to produce a straight fork that still pulls to one side. However, the crude guy who uses the method I outlined above will make the bike ride straight without measurement. The only problem with this is that the bike may pull to one side when braking because the fork really isn't straight but is compensated for lateral balance. This problem has mystified more bike shops because they did not recognize the problem. Sequentially brazing or welding fork blades often causes unequal length blades and bike shops usually don't question this dimension. However, in your case I assume the bike once rode straight so something is crooked --------------------------------------------------------------------------- Frame repair (David Keppel pardo@cs.washington.edu) (Disclaimer: my opinions do creep in from time to time!) When frames fail due to manufacturing defects they are usually replaced under warranty. When they fail due to accident or abuse (gee, I don't know *why* it broke when I rode off that last motorcycle jump, it's never broken when I rode it off it before!) you are left with a crippled or unridable bike. There are various kinds of frame damage that can be repaired. The major issues are (a) figuring out whether it's repairable (b) who can do it and (c) whether it's worth doing (sometimes repairs just aren't worth it). Kinds of repairs: Bent or cracked frame tubes, failed joints, bent or missing braze-on brackets, bent derailleur hangars, bent or broken brake mounts, bent forks, etc. A frame can also be bent out of alignment without any visible damage; try sighting from the back wheel to the front, and if the front wheel hits the ground to one side of the back wheel's plane (when the front wheel is pointing straight ahead), then the frame is probably out of alignment. * Can it be repaired? Just about any damage to a steel frame can be repaired. Almost any damage to an aluminum or carbon fiber frame is impossible to repair. Titanium frames can be repaired but only by the gods. Some frames are composites of steel and other materials (e.g., the Raleigh Technium). Sometimes damage to steel parts cannot be repaired because repairs would affect the non-steel parts. Owners of non-steel frames can take heart: non-steel frames can resist some kinds of damage more effectively than steel frames, and may thus be less likely to be damaged. Some frames come with e.g., replacable derailleur hangers (whether you can *get* a replacement is a different issue, though). Also, many non-steel frames have steel forks and any part of a steel fork can be repaired. Note: For metal frames, minor dents away from joints can generally be ignored. Deep gouges, nicks, and cuts in any frame may lead to eventual failure. With steel, the failure is generally gradual. With aluminum the failure is sometimes sudden. Summary: if it is steel, yes it can be repaired. If it isn't steel, no, it can't be repaired. * Who can do it? Bent derailleur hangers can be straightened. Indexed shifting systems are far more sensitive to alignment than non-indexed. Clamp an adjustable wrench over the bent hanger and yield the hanger gently. Leave the wheel bolted in place so that the derailleur hanger is bent and not the back of the dropout. Go slowly and try not to overshoot. The goal is to have the face of the hanger in-plane with the bike's plane of symmetry. Just about any other repair requires the help of a shop that builds frames since few other shops invest in frame tools. If you can find a shop that's been around for a while, though, they may also have some frame tools. * Is it worth it? The price of the repair should be balanced with * The value of the bicycle * What happens if you don't do anything about the damage * What would a new bike cost * What would a new frame cost * What would a used bike cost * What would a used frame cost * What is the personal attachment If you are sentimentally attached to a frame, then almost any repair is worth it. If you are not particularly attached to the frame, then you should evaluate the condition of the components on the rest of the bicycle. It may be cheaper to purchase a new or used frame or even purchase a whole used bike and select the best components from each. For example, my most recent reconstruction looked like: * Bike's estimated value: $300 * Do nothing about damage: unridable * Cost of new bike: $400 * Cost of new frame: $250+ * Cost of used bike: $200+ * Cost of used frame: N/A * Cost of repair: $100+ * Personal attachment: zip Getting the bike on the road again was not a big deal: I have lots of other bikes, but I *wanted* to have a commuter bike. Since I didn't *need* it, though, I could afford to wait a long time for repairs. The cost of a new bike was more than I cared to spend. It is hard to get a replacement frame for a low-cost bicycle. I did a good bit of shopping around and the lowest-cost new frame that I could find was $250, save a low-quality frame in the bargain basement that I didn't want. Used frames were basically the same story: people generally only sell frames when they are high-quality frames. Because the bike was a road bike, I could have purchased a used bike fairly cheaply; had the bike been a fat-tire bike, it would have been difficult to find a replacement. The cost of the frame repair included only a quick ``rattlecan'' spray, so the result was aesthetically unappealing and also more fragile. For a commuter bike, though, aesthetics are secondary, so I went with repair. There is also a risk that the `fixed' frame will be damaged. I had a frame crack when it was straightened. I could have had the tube replaced, but at much greater expense. The shop had made a point that the frame was damaged enough that it might crack during repair and charged me 1/2. I was able to have the crack repaired and I still ride the bike, but could have been left both out the money and without a ridable frame. * Summary Damaged steel frames can always be repaired, but if the damage is severe, be sure to check your other options. If the bicycle isn't steel, then it probably can't be repaired. --------------------------------------------------------------------------- Frame Fatigue (John Unger junger@rsg1.er.usgs.gov) I think that some of the confusion (and heat...) on this subject arises because people misunderstand the term fatigue and equate it with some sort of "work hardening" phenomena. By definition, metal fatigue and subsequent fatique failure are well-studied phenomena that occur when metal (steel, aluminum, etc.) is subjected to repeated stresses within the _elastic_ range of its deformation. Elastic deformation is defined as deformation that results in no permanent change in shape after the stess is removed. Example: your forks "flexing" as the bike rolls over a cobblestone street. (an aside... The big difference between steel and aluminum as a material for bicycles or anything similar is that you can design the tubes in a steel frame so that they will NEVER fail in fatigue. On the other hand, no matter how over-designed an aluminum frame is, it always has some threshold in fatigue cycles beyond which it will fail.) This constant flexing of a steel frame that occurs within the elastic range of deformation must not be confused with the permanent deformation that happens when the steel is stressed beyond its elastic limit, (e. g., a bent fork). Repeated permanent deformation to steel or to any other metal changes its strength characteristics markedly (try the old "bend a paper clip back and forth until it breaks" trick). Because non-destructive bicycle riding almost always limits the stresses on a frame to the elastic range of deformation, you don't have to worry about a steel frame "wearing out" over time. I'm sorry if all of this is old stuff to the majority of this newsgroup's readers; I just joined a few months ago. I can understand why Jobst might be weary about discussing this subject; I can remember talking about it on rides with him 20 years ago.... --------------------------------------------------------------------------- Weight = Speed? (Jobst Brandt jobst_brandt@hplabs.hp.com) > I was wondering if anyone could help me figure out why heavier > people roll down hills faster than the little scrawnies like myself. Surface as well as cross sectional area of an object (a human body) increases more slowly than its weight (volume). Therefore, wind drag, that is largely dependent on surface, is proportionally smaller for a heavier and larger object than a smaller one of similar shape and composition. A good example is dust at a rock quarry that remains suspended in the air for a long time while the larger pieces such as sand, gravel, and rock fall increasingly faster to the ground. They are all the same material and have similar irregular shapes but have different weight to surface area ratios, and therefore, different wind resistance to weight ratios. This applies equally to bicyclists coasting down hills if other factors such as clothing and position on the bicycle are similar. --------------------------------------------------------------------------- Aligning SPD Cleats (Bill Bushnell bushnell@lmsc.lockheed.com) Six adjustments can be made when setting up SPD cleats. With the foot parallel to the ground and pointing in the direction of travel, the adjustments are: 1) Left/right translation 2) Front/back translation 3) Up/down translation 4) Front to back tilt 5) Side to side tilt 6) Azimuth, often called "rotation" Front to back tilt is adjusted as the bicycle is pedaled since the pedals themselves rotate freely in this direction. Some people may need to adjust side to side tilt, but this requires the use of shims which are not provided and can cause the cleat to protrude beyond the tread of the shoe. Custom insoles that have one side slightly thicker than the other may have the same effect as shims between the cleat and the shoe. Separate up/down adjustments for each leg may be necessary for individuals with established leg length differences. To adjust up/down translation in one shoe use a combination of an insole and raise or lower the seat. To make small up/down changes equally in both legs, simply raise or lower the seat. The usual adjustments for SPD cleats are left/right, front/back, and Azimuth. Of these Azimuth is the most sensitive. For most people these three adjustments are sufficient to obtain a comfortable alignment. ----------------- Aligning SPD cleats: Position the cleat so that it lies on the imaginary line between the bony knob on the inside of your foot at the base of your big toe and a similar but smaller knob on the outside of the foot at the base of the smallest toe. Set azimuth so that the pointed end of the cleat points directly toward the front of the shoe. If you're switching from clips and straps, and you are satisfied with your current alignment, use the following alternate method. Position your SPD shoe fully in the clip of your old pedal and align the cleat to the spindle of your old pedal. Center the cleat in the X direction, leaving room to adjust either way should the need arise. Some people find pedaling more comfortable if their left and right feet are closer together. This is sometimes called the "Q-factor". If you prefer to start with a low Q-factor, then move the cleat so that it is as close as possible to the outside of the shoe. Tighten both cleat bolts before engaging the pedal. Adjust the release tension of the pedals so that it is somewhere in the low to middle part of the tension adjustment range. The higher the release tension, the harder it will be for you to disengage the pedals when dismounting. The lower the release tension, the easier it will be for you to inadvertently pull out of the pedals, especially when standing and pedaling. If you stand often to power up hills, consider setting the initial release tension higher as an unwanted release under these conditions can result in a painful spill. See the pedal instructions. Mount your bike on a trainer, if you have one, to make preliminary cleat and release tension adjustments. Practice engaging and disengaging the pedals a few times before you take a real ride. Soon you will find this easy. If you notice that a shoe rubs a crank or chainstay, adjust left/right translation and azimuth until the shoe no longer rubs. As you pedal, you will probably find the initial azimuth uncomfortable on one or both legs. Notice how your foot would like to rotate. Adjust the azimuth of the appropriate cleat in the same direction your foot wants to rotate. For example, if your foot wants to rotate clockwise, adjust the azimuth of the cleat (when looking at the bottom of the shoe) clockwise. Start by making moderate corrections. If you overshoot the adjustment, correct by half as much. As you approach optimum azimuth, you may need to ride longer before you notice discomfort. Take your bike off the trainer, and go for a real ride! And bring your 4mm allen key. You may find very small azimuth adjustments difficult to make. This happens because the cleat has made an indentation in the stiff sole material (usually plastic, sometimes with a tacky, glue-like material where a portion of the sole was removed). When you tighten the cleat after making a small correction, it will tend to slide back into the old indentation. Try moving the cleat one millimeter or so to the side or to the front or back, so the cleat can no longer slip into the old indentation pattern as it is being tightened. Pain in the ball of your foot can be relieved. One way is by moving the cleat rearward. Start by moving the cleat about two to three millimeters closer to the rear of the shoe. Be careful not to change the azimuth. When pedaling notice how far your heel is from the crank. After making a front/rear adjustment, check to make sure the crank-heel distance has not noticeably changed. Moving a cleat rearward on the shoe has the effect of raising your seat by a lesser amount for that leg. The exact expression is messy, but for an upright bike, the effect is similar to raising your seat by about y/3 for that leg, where y is the distance you moved the cleat to the rear. For example, if you move your cleat 6 millimeters to the rear, you might also want to lower your seat by about 2 millimeters. Remember, though, that unless both cleats are moved rearward the same amount, your other leg may feel that the seat is too low. Another way to relieve pain in the ball of the foot is to use a custom orthotic and/or a padded insole. Most cycling shoes provide poor arch support and even poorer padding. After riding for a while with your aligned cleats if you find yourself pulling out of the pedals while pedaling, you will need to tighten the release tension. After tightening the release tension the centering force of the pedals will be higher, and you may discover that the azimuth isn't optimum. Adjust the azimuth as described above. On the other hand, if you find you never pull out of the pedals while pedaling and if you find it difficult or uncomfortable to disengage the cleat, try loosening the release tension. People whose knees like some rotational slop in the cleat may be comfortable with very loose cleat retension. As with any modification that affects your fit on the bike, get used to your pedals gradually. Don't ride a century the day after you install SPDs. Give your body about two or three weeks of gradually longer rides to adapt to the new feel and alignment, especially if you've never ridden with clipless pedals before. Several months after installing SPDs, I occasionally tinker with the alignment. After performing the above adjustments if you are still uncomfortable, seek additional help. Some people can be helped by a FitKit. If you're lucky enough to have a good bike shop nearby, seek their advice. ----------------- Tightening cleat bolts: Tighten cleat bolts until they _begin_ to bind. This will happen when further tightening produces a vibration or squeal from the cleat. Tighten no further or you may damage the mounting plate on the inside of the shoe. After living for a while with a comfortable alignment, remove each mounting bolt separately, apply blue loctite on the threads, and reinstall. Should you later find you need to loosen a bolt to adjust the alignment, you will have to reapply the loctite. Keeping the Pedal/Cleat interface clean: Occasionally you may find the pedals suddenly more difficult to disengage. This usually happens because dirt or other contaminants get caught in the cleat or pedal mechanism. I have found that a good spray with a hose quickly and cleanly washes off dust, mud, or other gunk from the pedal and cleat. You may also wish to spray the pedal with a light silicone or teflon lubricant. Acknowledgements: John Unruh (jdu@ihlpb.att.com) Lawrence You (you@taligent.com)