Just saw a guy at the shop torque his seatpost clamp to 8nm

Was working on a customer's bike at The Bike Hub in Portland yesterday and a dude walks in asking for a new seatpost because his carbon one cracked. I asked how tight he went and he said "8nm like the manual said." Problem is that was for the binder bolt on a different brand's frame, not his specific post. I've seen three posts crack this month alone from people just cranking down without checking the actual torque spec on the part itself. Anyone else deal with folks mixing up torque values between components?

3 comments

3 Comments

grace_white4d ago

Yeah I used to be one of those people who just followed whatever torque spec was printed on the frame near the seatpost clamp. Thought I was being careful by using a torque wrench at all. Then my friend's carbon post snapped on a group ride and we realized he'd been torquing it to the frame's 6nm spec when the post itself said 5nm max. That tiny difference cracked it right at the clamp line. Swapping parts between bikes taught me the hard way that torque specs are specific to each component, not just general guidelines. Now I always look up the post manufacturer's own spec before touching anything.

morgan_ramirez4d ago

Honestly, dude, 6nm vs 5nm usually isn't snapping posts.

rileynelson4d ago

Huh, never thought about temperature before. @morgan_ramirez, carbon frames and posts expand differently in heat, so a cold torque setting could be way off after the bike sits in the sun.