Originally Posted by
tpy2010
My advice, by a good bike, ride hard and don't worry.
Exactly.
I'm not sure if it's differences in ride style that cause the problems or luck of the draw from a manufacturing lot, but I've only broken one frame in my life, and that was an old Crack 'n' Fail era bonded aluminium MTB. I've ridden various grades of steel and alu since then, and even carbon tubes on aluminium lugs/stays (90s Trek 2100) without any problems. Heck, I raced on that 2100 at just over 200 pounds and never even broke a component outside of crashing.
Meanwhile, I've got some 140 - 150 pound friends that bust equipment like it was their job. Snapped crankarms, broken pedal spindles, chainstays/seat-tubes/downtubes cracking around the junctions... And they're not racers, either. Just avid riders who put frequent long mile days in on the bike.