Dear Lennard,
Do I have to buy Campy's new tool to properly install the new PermaLinkin a Campy 10-speed chain? I do have a Shimano 9-speed and Park 9-speedchain tools on hand.
MortDear Mort,
You can do it with a standard chain tool, but you have to be extremelycareful with alignment of the two chain ends with each other, somethingwhich Campy’s new tool ensures. I have done it many times with a Shimanochain tool without problems. By the way, it is just a pin, albeit it avery precisely shaped one, not a PermaLink anymore.
LennardThere's gotta be an easier way to do this
Dear Lennard,
After a bad crash I bent my rear disc brake rotor. I spent nearly anhour trying to true it using the pads in the caliper as a guide and myfingers to bend it back into shape. I achieved an acceptable result butI wish there were an easier way. Is there?
ErikDear Erik,
Yes, Morningstar makes a fantastic tool for this, which I use frequentlyand am super-glad I have. It has a dial indicator and allows you to getit extremely straight in a short amount of time. I reviewed it in VeloNewsin the 7/29/02 issue.
LennardCrank length
Dear Lennard,
I own a 61cm steel LeMond. The bottom bracket drop is 68mm, and I wantto know how long of a crank arm can I install on the frame? My inseam is38.5, and I have quite a bit of seat post showing. The stock arms on mybike are 175mm.Will I be able to lower my seat post cm for cm the length that I increasemy crank length?
TimDear Tim,
With your 27cm BB height, you have decent clearance for 180mm, butI wouldn’t ride a criterium on anything longer than that. I have one bikewith a 27.8cm bottom bracket height and am running 202mm cranks on it withno problem. In the past, I was running those cranks on a bike with a 27.2mmbottom-bracket height, but that seemed a bit too low at times, so I builtthis new frame with 6mm higher clearance. The key thing is that I knowexactly the point at which the pedal would hit, and I take the extra timeto come out of the corner a bit further before I start pedaling again.The lower center of mass of using as low of a BB as I can get away withis an advantage for someone as tall as me. That’s why I run a lower BBthan may seem prudent, but this is just on my own bike – I would not presumeto make this choice for someone else).When just riding hard, including on twisting mountain roads, clearanceis no problem, but I can take the extra time before I start pedaling again,and in most road-race situations you can also take this time. But I havenot raced a criterium in probably 20 years, and I certainly cannot pedalthrough corners with these cranks on this low BB in the way that wouldbe required in many circuit-type races.As for your second question: yes, you will be able to lower your seatpost cm-for-cm the length that you increase your crank length.
LennardKsyrium and Campy
Dear Lennard,
My local bike shop tells me that I can't marry a Ksyrium SSC SL rearwheel to a Campy Chorus cogset. Is this right? I thought the "problem"existed a couple of years ago, but that Mavic now made a Campy-compatibleversion of the Ksyrium.
AlanDear Alan,
You are right. There is a Campy freehub option for the Ksyrium.
LennardRise and run
Dear Lennard,
I very much appreciated your article in VeloNews on calculatingrise and run for stems. VeloNews had a link to JavaScript calculator, whichI used many times figuring out geometry for a new frame. The link seemsto be gone. Any chance you can direct me to an active link or do I haveto get out my engineering calculator?
Thank you for the contribution you make to all of us cyclists.
DavidDear David,
I went ahead and put the stem calculator tool up on www.zinncycles.com,so you can find it there and don’t need to get out your engineering calculator!
LennardLefty loosey or...?
Dear Lennard,
My new mountain bike has Shimano's new RapidRise XTR rear derailleurand I have a question about adjusting it. I can not intuitively seem tofigure out which way to turn the cable adjuster knob at the shifter tomake it work. I end up loosening it and then tightening it, sometimes severaltimes back and forth, until the shifting improves. The RapidRise systemoperates in reverse of the old RapidFire system. Therefore, should I firstturn the knob clockwise to adjust for cable stretch instead of the triedand true counterclockwise, which solved most adjustment issues with theolder RapidFire system?
BrettDear Brett,
If you want the derailleur to move more rapidly to a larger cog (lowergear), you reduce the cable tension by turning the barrel adjuster in (clockwisewhen viewed from the end the housing protrudes from). This allows the springto move the derailleur inward further.Similarly, if you want the derailleur to move outward further to betterreach a smaller cog (higher gear), you increase the cable tension. Youdo so by backing the barrel adjuster out (rotate it counterclockwise whenviewed from the end the housing protrudes from). Since it is you, not thespring, that is pulling the derailleur outward to ever-smaller cogs, youneed more cable tension if you want the derailleur to move further outward.As for adjusting for cable stretch, as the cable stretches, the derailleurwill move to larger cogs faster and slower to smaller cogs. This is theopposite of a standard derailleur, which will be easier to shift to smallercogs and harder to shift to larger ones. To counteract the stretch, youstill back the adjuster out (counterclockwise) – just as before. Cablestretch will still happen, and the cable will still need to be tightenedup. The difference is only that the symptom of the problem will now bedifferent.
LennardPosition and sun block
Dear Lennard;
I have two questions for you:1. I noticed in this year's Giro that many (most?) of the riders hadmoved their shift/brake assemblies much further up the drops than previously.This has always seemed to me to be a much more comfortable position, eventhough one sacrificed some "aerodynamics" by virtue of riding more upright.The pros must be making some adjustments in bike fit to do this withoutundue costdo you know what they are doing (longer stems?), and how we meremortals can do the same if we want to try it?2. Have you heard of any reports of sun block causing a deteriorationor breakdown in the finish of certain materials, such as carbon frame clearcoat, and the paint and materials used in/on various watches and HR monitors?I suspect that's what might be happening to my Trek and my Timex; it maybe why the band on my Polar HRM seems to be changing color. The guys atmy favorite bike shop don't think this is likely, but I have pretty goodanecdotal evidence from friends and associates that this might not be arare occurrence.
ChrisDear Chris,
Well, each rider's setup is specific to them, so there is no blanketanswer, but I have noticed that stems seem to be lower than in the past.This is particularly true on the bikes of taller riders. Check out thesetup of Gianpaolo Mondini on his Domina Vacanze Specialized. The setupof his taller teammate, Mario Scirea, is even more extreme. Michele Scarponi’sbike, by contrast, is a more normal setup.I don't know about the sun block. Anybody have an answer for Chris?
LennardFeedback on squeaking Look pedals
Lennard;
The squeak you mentioned in the column on the Look pedals, is thisthe cleat moving up and down on the pedal? If so, I stopped this squeakby using paint and painting the contact points of the cleat. Solves theproblem for about a week then I repaint.
MarieDear Marie,
Yes, that’s the squeak. Sounds like a good solution!
LennardFeedback on parts mixing
Lennard;
In response to Bill's question about a chain for such: I have Campy8-speed, but with Shimano compatible hub, cogs, and spacers to convertto Campy shifting. Front rings are Campagnolo. I've had good luck runninga SRAM PC-68, no problems whatsoever.
RickFeedback on Ksyrium braking problem
Dear Lennard;
I can totally relate to the braking problem with the Mavic Ksyriumrims. My Mavic Cosmos rims gave me the same problem. The soft Kool-Stopblack pads that worked so well on my Rolf Vector Comp rims were a menaceon the Cosmos rims. My Cosmos rims have grooves I can feel, which I'm guessingimprove performance when wet, and they have a rougher feel in general thanany other rims I've owned, Mavic or otherwise. When I first put on thenew wheels, the braking was just awful - very grabby - almost unrideable.I can see how someone could do an endo in a panic stop. The solution forme was to sand the rims to smooth them out, but more important, to go toa harder pad compound - the salmon severe weather pads in my case (shadesof the mountain bike). The stock Shimano pads also worked pretty well,but seemed a bit hard on the rims. The brakes still don't modulate quiteas well as the black pads on the Rolf rims, but they are good enough andthey seem to be getting better as the harder pads wear down the rim's surfacefinish. You mentioned in one of your books that Scotchbrite pads are goodfor this, so I'll give that a try and see if I can accelerate the process.
Steve

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Technical writer Lennard Zinn is a frame builder, a former U.S. national team rider and author of several books on bikes and bike maintenance including the pair of successful maintenance guides " Zinn & the Art of Mountain Bike Maintenance" and "Zinn & the Art of Road Bike Maintenance."Zinn's regular column is devoted to addressing readers' technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn. Zinn’s column appears here each Tuesday.