[CR]Predicting/preventing NR/SR crank breakage

(Example: Framebuilding:Technology)

From: <PBridge130@aol.com>
Date: Wed, 28 Aug 2002 10:35:48 EDT
To: classicrendezvous@bikelist.org
Subject: [CR]Predicting/preventing NR/SR crank breakage

Has this subject been done to death prior to my arrival?

I went down very hard once, when my N/SR crankarm snapped, a couple inches up from the pedal. I was going fairly fast at the time. In addition to the normal rash, I had a helmet that was crushed on one side, and only the slightest of headaches (there's gotta be a lesson in there somewhere).

I think it's understandable that my enthusiasm for riding hard on similar cranks has been dampened, perhaps explaining my enthusiasm for Stronglight-equipped bikes (I've never heard of one of those breaking, and if they do, I don't think I want to know about it).

I just measured the broken end. Break occurred two inches from center of pedal, straight across the arm, 172.5 arm, "11" in a square.

So. What do I watch for? How do I anticipate catastrophic failure, and avoid it? Hanging the bike on the wall and admiring it while quaffing a brewski and smoking a cigar might be an acceptable strategy, but probably isn't the ideal one.

Thanks y'all,

Peter Bridge
DenCO