Re: [CR]Predicting/preventing NR/SR crank breakage

(Example: Framebuilders:Mario Confente)

Date: Wed, 28 Aug 2002 08:05:35 -0700 (PDT)
From: "Tom Dalton" <tom_s_dalton@yahoo.com>
Subject: Re: [CR]Predicting/preventing NR/SR crank breakage
To: classicrendezvous@bikelist.org
In-Reply-To: <3f.10ac3374.2a9e39c4@aol.com>


I suspect the fact that you have never seen or heard of a Stronlight crank breaking is a reflection of the reality that in the last 30 years, there has probably been one hard-ridden Stronglight crank for every several hundred Campy. Campy's reputation for durability used to (and may still) lead people to use their parts way, way beyond the reasonable service life. Back in the day, people use to buy and use third and forth hand Campy stuff with no knowledge of previous use. It may be a good thing that modern equipment doesn't function after a certain amount of wear, or becomes unservicable due to incompatibilities. If old Campy cranks broke, what is going to happen to all these sub- 200g handlebars? As to predicting... there is almost always some sort of visible, incipient crack before an arm (or frame) breaks. Inspect those cranks. Tom PBridge130@aol.com wrote:

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 _______________________________________________

---------------------------------
Do You Yahoo!?
Yahoo! Finance - Get real-time stock quotes