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Old 04-19-18 | 10:30 PM
  #50  
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Andrew R Stewart
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Joined: Feb 2012
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From: Rochester, NY

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB

Real life does things to theory, speculations or hope. When I read people saying that a jig insures alignment and I see frequently enough misaligned carbon/bonded frames I have to side on what I see. I've seen many minor wheel sitting "offnesses" on many brands and types of bikes (mostly road as they comprise most of the carbon built bikes I've worked with), both forks and rear ends. The tight clearances of TT bikes have been especially prone to power induced tire rubs when this off center wheel stuff happens. I have shifted the dish of a few wheels to compensate, not the best solution but sometimes you do what you need to. I have filed quite a few drop outs, mostly on forks, to allow the wheel to center at the brake/crown/stays.

This is rather interesting to me as a many year "gentleman builder" and also as a front line shop wrench. What I do in a LBS isn't always what I am happy with at home in my own shop. For years I have wondered about carbon frame alignment, seeing what I see and knowing what I do about steel frames. I've never bothered to pursue carbon frame tolerances in a setting where real numbers are found. But this thread has me rethinking my lack of motivation to measure carbon frames on my flat surface and use the same methods of testing I apply to my own (and other's) steel frames. (Why take time when I had no interest in trying to make one and also knowing that any corrections are limited?) So I have a new project that I'll follow up on in my own sweet time. At some point, likely this fall, I'll do some checking on whatever carbon frames I can come across (and take home for a while) and post back. Andy
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