I agree, to some extent. That's Statistics 101. The sky is blue. But anything is *possible* - I might get struck by a motor vehicle tomorrow while riding my bike in town and be killed, or I might get T-boned by some inexperienced teenaged driver while driving my car, and be killed. Actuarily, those two things are much more likely to happen than my vintage Record crank arm breaking tomorrow. The point is, life has inherent risks that we encounter every day, and breaking an old crank arm is not something that's even on my radar as an issue to worry about.
I'll assume from your comments that you've broken zero of them personally.....
So, the total of vintage Record crank arms personally broken by current members of this list during their entire lifetimes and reported to me (so far) is..... zero. The only e-mails I've received in response to my query have been to say that he or she hasn't ever broken one. Folks, if you've ever personally broken any brand of vintage crank arm (let's stay within CR guidelines), please e-mail me with the details. I'll keep a running tally, and report back to the group in a week or two with the findings.
This "problem" has been way overstated and hyped over the years. Lots of crank brands can be broken by the right person under the right circumstances. Some folks break parts all the time, most don't. Campy cranks are often saved and used again (and again, and again) when other brands would have been scrapped. See again Damon Rinard's site. QED.
http://pardo.net/
Hi Greg, The point is that if you keep using the SAME crank, based on the fact it hasn't broken yet, you might possibly be tempting fate. Now, if you are in the easy-on-equipment category, then you may be significantly increasing the fatigue life of each given component. But, as you take any given component to greater and greater miles, the probability of a failure for that component is increasing. In fact, the probability of a failure of a given component per additional mile ridden is increasing at an increasing rate. It is the way that mortality tables work. If you are healthy and young, the likelihood of death is quite low in any given year when you are young. But as you age, the likelihood of death in a given year increases greatly as you become quite old.
After being in the vintage bike biz for many years, I spoke with many folks who broke cranks. A common tale was that failure occured after 10 to 15 years of riding perhaps 3-5K per year. Most of these folks were probably pretty surprised since they went so many years without problems! Now, for those of us who are smooth and who rotate bikes and never put huge miles on any one particular crank, failures are far and few between. That is why I have never really worried about crank failure myself except that I stopped using high mileage used cranks of unknown origin on bikes I might ride hard. Mike Kone in Boulder CO
Hi Mike: Two comments: 1) Yes! I agree 100% that breakage (of most, but not all, vintage bike parts) is primarily a riding style issue (and it's probably hard to define what exactly that means). Some folks break Campy cranks, other brands of cranks, BB spindles, hub axles, frames, steerer tubes, bars, stems, saddle frames, Ergal rims, chains, freewheel bodies, etc. etc. The vast majority of us almost never break anything. That can't be a coincidence. 2) I'm not sure exactly what you are trying to say after that, but of course those cranks can fail at the arm-to-spider junction. Never said they didn't/wouldn't. I only said that a majority of the ones that did break, didn't break there, and that they can have a microcrack there for a very long time without failing. I stand by those comments 200% (wait - is that possible? :-0 ). If you are trying to say that the 100-200 thousand miles that my wife and I have ridden on Record crank arms over the last three decades without a single failure doesn't mean that we are highly unlikely to break one tomorrow, then I respectfully disagree with that thought 100%. Clearly, she and I are both in the large "never broke nuthin'" group. ALL LIGHTWEIGHT BIKE PARTS CARRY SOME RISK. Life is full of risk assessment. Getting in a motor vehicle to drive to work in the morning is a risk/benefit decision. Eating fast food is a risky activity. I can assure y'all that I lose absolutely no sleep at night due to worrying about part breakage on my fleet, which is almost entirely vintage bikes. I do, however, keep most of my machines extremely clean, to help see problems if they arise. I also dig riding a super-clean bike. Can't help it, I'm a little bit OC.... Cheers, and keep those clean Strada 175s headin' my way for proper "disposal"! Greg Parker Ann Arbor, Michiagn P.S. Mike, how many vintage Record crank arms have you personally broken while riding...? P.P.S. How many has everyone on this entire list personally broken? Bet it's a small number. ("Heard about one" or "a customer of a guy I know broke one" doesn't count).
The debate about Campy crank breakage continues -but unless I missed something a very important piece of info was left out of the messages I read. Yes - crank failure is typically (but not always as discussed below) a fatigue issue. But, riding style is extremely important in determining when the fatigue failue is likely. As engineering friends tell me, on every revolution of the cranks the rider puts a peak moment on the arm. Riders that are heavy and powerful but very even in their stroke may cause only a modest peak moment, while a choppy lightweight rider might actually put a higher moment on the arm. If I'm interpreting what I've been told correctly, the relationship between fatigue failure has I believe a square functional relationship to the peak moment. So, the choppy lightweight rider is much more likely to have a failure than the heavier, powerful, but smooth rider. This correlates well with some evidence I've seen. I know of one super strong rider (Olympic medal winner) who never broke much of anything. I then had a regionally strong local rider who came into Bicycle Classics inc. years ago who said he broke 27 crankarms - (some on the first day of use in one sprint! - not even a fatigue failure). And no, don't believe that cranks don't fail at the arm spider junction. Years ago I discussed this with a distributor and former Campagnolo employee who had seen many hundreds of failed cranks. Yes, they most often failed near the pedal, but he assured me that many also failed at the spider/arm junction. The kicker is that you can see the crack at the spider/arm junction but you can't usually identify an arm that is about to fail elsewhere. And finally, the idea that Campy NR arms are safe because "I've never broken one yet" is false. Yes, if you are a super smooth rider your risk is lower, but as the miles go on the probability of a failure increases. No matter what your past experience kids you into believing, the risk of failure is increasing with every stroke. Mike Kone in Boulder CO
> In a message dated 9/14/2004 2:08:23 PM PST, gpvb1@comcast.net writes:
\r?\n> Absolutely, don't ride the old Campy cranks. Instead, send them postage
\r?\n> pre-paid to me, and I will see that they are properly recycled. If they are
\r?\n> clean-looking Strada 175s, I may even split the postage with you! ;-)
\r?\n> It has been my experience that some folks experience breakage of these, and
\r?\n> the vast majority of us don't. It doesn't correlate well to rider weight or
\r?\n> power or fitness level, or even to the vintage or age of the cranks to some
\r?\n> extent (although I would say that generally the ones that break are from 1968 to
\r?\n> about 1985, i.e. the "classically" shaped 144 BCD ones - the earlier "boxy" ones
\r?\n> had a beefier cross-section and that seems to be a factor). It does correlate
\r?\n> very strongly to the total mileage on them, as it's a fatigue failure. As
\r?\n> Phil stated, these have some well-known failure modes, but in nearly three
\r?\n> decades of riding them almost exclusively, I've never broken one, nor has my
\r?\n> wife,
\r?\n> nor has anyone I've ever ridden with on a regular basis. Recently, I replaced
\r?\n> my wife's SR cranks at about 70,000 miles pre-emptively, more for cosmetic
\r?\n> reasons than concern over any impending failure. It certainly does happen,
\r?\n> though,
\r?\n> and somewhat more often with these old cranks than with most other comparable
\r?\n> old cranks of the same period. Check out Damon Rinard's site of crank
\r?\n> failures for pics. of lots of brands of broken crank arms. It's sobering, but it
\r?\n> doesn't stop me from using them.Check for cracks often!
\r?\n> Regards, Greg Parker
\r?\n> -----------------------------------------------------------------------------
\r?\n> Greg-
\r?\n> It sounds like your experience has been a lot like mine, especially the 1985+
\r?\n> SR/NR models. Even though I think its out of the "CR timeline", that's the
\r?\n> time that Campy got wise about designing in extra material at the
\r?\n> spider-arm/crank arm junction. You probably know them as the non-fluted crankarm
\r?\n> design,
\r?\n> but other manufacturers, i.e., Gipiemme were designing in that extra-beefiness
\r?\n> about 4 or 5 years before Campy. In any case, my experience is a lot like
\r?\n> yours, I have never had any cranks break on me, but have seen after 10+ years
\r?\n> riding the same crank, very minor stress cracks did start to form at that
\r?\n> critical
\r?\n> junction. I am sure everybody is aware of the most common prophylactic for
\r?\n> this problem is to file smooth the "stress-risers". I have had nothing but good
\r?\n> luck with this method.
\r?\n> Cheers-
\r?\n> Dave Anderson
\r?\n> Cut Bank MT