Originally Posted by
Campag4life
Just don't agree. Fatigue limit can be tested and is in the laboratory by major manufacturers. I personally have been riding Al bikes a long time and have never seen a fatigue failure. I am sure they maybe out there but so incredibly rare. Force/deflection X's no. of cycles to fatigue. Any frame can be tested in the laboratory at higher forces and larger frame bending amplitudes than a frame would see in the field to failure. Likely some Al frames stroking in the lab throughout the world as I type this.
I have broken two aluminium frames due to fatigue(on the top tube, about an inch from where the top tube meets the seat tube), neither bike lasted 12 months.
I am 400lbs though.