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Technical Q&A with Lennard Zinn: Landis’s drivetrain, Hincapie’s steerer, Thomson stem and chain-pin replacement

  • By VeloNews.com
  • Published Jul. 12, 2006

By Lennard Zinn

Landis’s drivetrain doesn’t look standard
Dear Lennard,
What’s up with the crank used by Floyd Landis? And What about Landis’s rear derailleur? It didn’t look like a normal Record model.
Chris

Dear Chris,
According to Francesco Zenere at Campagnolo, Landis’s rear derailleur and Ergo Power levers are 2006 series Record models. And BMC made a special cover for Landis’s Campy cranks for improved aerodynamic efficiency in time trials.
Lennard

What about Hincapie’s steerer in Paris-Roubaix?
Dear Lennard,
George Hincapie’s bike had a blasted and black-anodized aluminum steerer tube. Isn’t it true that sandblasting lowers the structural integrity of aluminum materials while anodizing only increases surface hardness but not the overall strength of the material? Would a shiny, smooth, heat-treated aluminum steerer tube have been stronger? Was the blasting and anodizing done purely for cosmetic reasons?Rob

Answer from Trek:
You are correct — Hincapie was riding an aluminum steerer tube in Paris-Roubaix. It was a 6061 aluminum steerer, the same one that we have been using on team and production bikes for over 8 years. Although we are experts in carbon fiber, we have always leaned to the conservative (and, hopefully, safe) side of fork technology. This has prompted us to remain with aluminum steerers, even for our team bikes.

To specifically address the question of your reader, the steerer tube that failed was not sandblasted. George’s fork, as well as almost every fork Bontrager makes, was actually shot-peened. The compressive residual stress from peening is what can extend the fatigue life of a part and is the same technique that you’ll find on most quality aluminum steerers, handlebars and seatposts. This technique is a well-accepted way of extending the life of an aluminum part. Second, the steerer was anodized to reduce corrosion.

As you may suspect, we have taken the issue of this failure very seriously — not just for the team, but for the safety of the tens of thousands of consumers riding identical equipment. After careful analysis of the broken parts, as well as replicating the failure in our test lab, it was a convergence of issues that combined to cause the failure, with the predominant factors being George’s first crash earlier in the day and the brutal nature of Paris-Roubaix itself.

The overriding message that this incident reinforces is that anytime a rider experiences a crash, it is imperative to check the bike over thoroughly before riding on, regardless of the type of bike or the type of fork. Of course George did not have the luxury of time in this instance, but most everyone else does. In fact, this is a good reminder of Bontrager’s carbon care policy. Essentially, if you have crashed a Bontrager part such as this Discovery Channel Team Issue fork, we’ll sell you a replacement part at a substantially reduced cost – no questions asked. When in doubt, throw it out. Check out the crash replacement program at www.bontrager.com.
Scott Daubert
Trek Team Liaison

Can stem crack steerer?
Dear Lennard,
I just got a sweet Scott CR1 and love it. I put a Thomson stem on it and love it. Recently a guy that I don’t know at a shop that I don’t know told me that combo is a bad idea because Thomson’s attachment system can crack the steerer tube. So now, all I can think about is my whole cockpit exploding a la George “Look at Me, I Can Fly” Hincapie at Roubaix.What have you heard? Is this guy looney-tunes like half the population of this town, or am I buying a new stem?
Jimmy

From Thomson:
This question arrives at Thomson about once a month. I believe one issue is that since the Elite Stem steerer clamp is different it raises concerns in some people about its safety for use on carbon. The steerer clamps surround the steerer tube more than 180 degrees and do not pinch the steerer tube. I can tell you that both in initial design and over time we have tested our stem with every available carbon steerer tube, road and mountain, and have never found an issue. This is one more opportunity to remind riders that carbon components demand care during installation, the use of a torque wrench is extremely important. As new brands and models of forks with carbon steerers enter the market, we purchase them and test with all our stems for compatibility. As an aside, we do the same thing with carbon handlebars as well. Our newer stems for 31.8mm diameter handlebars, X4 and X2, feature a more traditional steerer clamp with two bolts in the back of the stem. We made this move to save weight and eliminate any concerns over the non-traditional clamp of the older Elite 25.4 and 26.0mm stems.
David Parrett
Thomson

Pick new spot for chain-pin replacement
Dear Lennard,
In reading your column on chain pin replacement and repair it brought up a question that I’ve had for some time regarding my Shimano 9- and 10-speed chains. As I frequently remove my chain for cleaning and maintenance purposes, is it advisable to re-use the same link location for inserting the new connector pin or should I periodically replace different pins? If so, how many times is this acceptable?
Chris

Dear Chris,
Always pick a new spot; don’t re-use the same spot, as the hole gets larger each time. Shimano recommends a maximum of three times to take apart and reassemble its chains. And I recommend always cleaning chains without master links on the bike and never taking one apart until you’re throwing it away!
Lennard


VeloNews technical writer Lennard Zinn is a frame builder (www.zinncycles.com),a former U.S. national team rider and author of numerous books on bikesand bike maintenance including the pair of successful maintenance guides”Zinnand the Art of Mountain Bike Maintenance” and “Zinnand the Art of Road Bike Maintenance” as well as “Zinn’sCycling Primer: Maintenance Tips and Skill Building for Cyclists.”
 
Zinn’s VeloNews.com column is devoted to addressing readers’ technicalquestions about bikes, their care and feeding and how we as riders canuse them as comfortably and efficiently as possible. Readers can send brieftechnical questions directly to Zinn (veloqna@comcast.net)Zinn’s column appears each Tuesday here on VeloNews.com.
 

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