Originally Posted by
FBinNY
A question for all those who feel that aluminum bikes are inherently more prone to failure than steel bikes.
Do you Fly? I don't mean by flapping your arms, but in ALUMINUM airplanes.
There is nothing wrong with aluminum bicycles, if they're built right, and set up correctly.
Usually when I see seat tube failures, they're not because of the material, but because the post wasn't inserted deep enough (1" below the bottom of the top tube. This kind of failure is relatively new, and the result of a design change where the tube extends above the top tube, rather than ending at the seat cluster.
There's nothing wrong with extended seat tubes, but they require extra attention to seatpost depth.
As an engineer that works in the aerospace field I would like to point out that aircraft have inspections every so many flight hours, and I don't mean someone just looking at them. They go through non destructive inspection (NDI), some of which involve an ultrasound machine used around known stress points. In addition limits are placed on aircraft and whenever these limits are exceeded they also go through NDI.