TIL I was over-tightening my bottom brackets for years

I had this old Cannondale road bike that kept making a creaking noise every time I stood up to pedal. I must have pulled the crankset off like 6 times, greased everything, and torqued it back down to the numbers in the manual. Then a buddy who races crits came over last month and watched me work. He just laughed and said "dude your shell is probably warped from cranking it down so hard." I looked it up and sure enough, some aluminum frames can distort if you go past 35 Nm on the cups. I backed it off to 30 Nm and the creak vanished. So now I'm wondering how many bottom brackets I've wrecked over the years. Has anyone else found a torque spec that worked better than what the factory says?

3 comments

3 Comments

aaron88415d ago

Man, that's the bike equivalent of stripping a screw and wondering why it won't hold. Aluminum frames are basically just beer cans with wheels. I bet half the weird noises people chase down are just their own past mistakes coming back to haunt them. My buddy torqued his BB to "all the ugga-duggas I could fit in there" and wondered why his bike felt like it was riding on square tires.

the_parker15d agoProlific Poster

Broke a chain once because I used chain lube that was literally just Wesson oil from the kitchen.

alicecooper15d ago

Agree with aaron884 about the ugga-dugga approach, it's wild how many people treat torque specs like suggestions and then wonder why their threads are mangled. I bet half the creaks in aluminum frames come from someone cranking down too hard years ago and warping the shell slightly, then it just stays that way forever.