Originally Posted by
Spoonrobot
From the very same vintage articles, just later on in the 1990s which we haven't gotten to yet. Aluminum bikes became significantly stiffer the longer they were in the market as they broke or failed under riders out in the world.
Cannondale itself increased the tubing diameter, and/or changed the butting profile and wall thickness to reduce flexibility of the rear triangle. I don't recall off the top of my head but it was significant - 30%+.
You can see it looking at the catalogs, the 1995 T1000 has significantly larger tubes compared to the 1985 T400. Marginal stiffness exceeding the difference between standard diameter and oversize steel tubing.
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!
Originally Posted by
Spoonrobot
This creates what is always the ultimate quandary.
If bicycle magazine editors were correct in praising 1980s aluminum frames for their superior comfort - what are we to make of their notion of the harshness of aluminum bikes after the mid-1990s?
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.)
There's another little time capsule here: the era when bike tire manufacturers lived and died according to what riders saw in bike magazines. Riders would look at ads, see that, e.g., a Specialized 23-mm tire weighed 50 grams less than another brand's tire of the same dimensions, and buy the Specialized tire. Unbeknownst to that rider, Specialized's tire was 2 or 3 mm narrower than the labeled size.
There's a good chance, in other words, that that Cannondale's 23-mm tires, so-called, were actually 21 mm, 20 mm, or even 19 mm in width.
The bike magazines eventually caught on and began including both the weight and the measured inflated width of tires in their reviews. (I could be wrong, but I seem to remember that Continental was one of the few companies that had labeled their tires accurately all along.)