Originally Posted by
Trakhak
About the rates of failure of different frame materials back then: there's a fascinating ongoing C&V thread where people are reporting their experience with frame failures. So far, the reports seem to be running about 5 or more failed steel frames to each aluminum frame---and the aluminum failures reported include Alan- and Vitus-built small-diameter-tube frames, known for being somewhat failure-prone.
Anecdotal, obviously, but I suspect that the ratio will continue to be roughly the same as the stories continue to roll in. I worked in a couple of the biggest bike stores in the area in the '80's and '90's, and that's about the proportion of damaged frames that I remember.
Cannondale's engineers were working to refine their designs throughout that period: hence the successive CAD---and, later, CAAD---series numbers, prominently labeled on each bike. They'd figured out early on that riding comfort did not decrease with increased structural rigidity and/but that the increased torsional and lateral rigidity did result in improved handling and wheel tracking. And the bikes kept getting lighter!
One of the articles SpeedOfLite posted was the earliest I've seen where the writer said that a Cannondale racing bike had a particularly hard ride. He blamed the frame but then swapped the tires (23 mm to 25, I think) and said the ride was much improved. Somehow he didn't draw the all-but-obvious conclusion. (The bike under review was a Crit Series, too. See my previous post on that topic.)
...)
I suspect some of the 5-1 ratio of steel failures to aluminum failures are due to there being so many old steel bikes out there, many that have been ridden hard and/or seen significant water and rust. Thousands of steel bikes built to lower standards because it's easy and people rarely get hurt with the failures so who care? High end oversized tube steel bikes are pushing the limits of wall thickness so small errors with heat of weld cause failures later. (Much more common the last 3 decades than 40 years ago). Many aluminum bikes have been overbuilt simply so they won't break.
And observations I've had with good steel and titanium bikes - vibration. With quality metal in the tubes and likewise quality steel forks, there is little damping. By all I read here and elsewhere, that should make my bikes torture to ride on rough roads, especially with the not so big tires and pressures I use. My two favorite rides are the ti fix gear of my avatar photo and the recently acquired early '80s Pro Miyata. Both are stiff as those materials go (and plenty stiff for this 150 lb climber at his 25 yo best long ago). I run 25c tires on them except 23c on the Miyata rear. 90-100 psi, 110 on the 23c.
Both of those bikes are classic 1980s steel race bike rides. I feel everything. But it just isn't an issue. Yes, like I did when I raced a million years ago, I de-weight the saddle a little and use my arms as shock-absorbered springs on the rough stuff. (Good practice any time on light tires and rims; stuff I love to ride.) Those bikes are alive! And I absolutely love it. It has always felt to me that nothing is lost energy-wise on such frames. (Yet we all knew back in the day that some riders needed super stiff bikes because they otherwise lost a ton of energy into the frame. The concept of "planing" always sounded bogus to me but my 1976 Fuji Pro flexed and I climbed that thing all over New England with zero penalty.)