Vent: An old timer at the co-op told me I was over-torquing my stem bolts and he was right

I've been wrenching on my own bikes for about 4 years now. Always used a torque wrench on my stem bolts, set it to the max spec on the part. Thought I was being careful. Then last winter at the co-op in Austin, this guy Bill who must be 70 years old watches me tighten a stem and just goes "you're gonna crack that steerer tube doing that." I got defensive at first, told him I was following the numbers. He said "the numbers on the part are for when everything is bone dry and brand new, which it never is." He showed me his method - grease the bolts, back the torque off by like 15%, and do a star pattern. Felt sketchy at first but I tried it on my commuter. 8 months later no slipping and no creaks. Has anyone else been told they were overthinking torque specs by an old school mechanic? I still use the wrench but I dial it back now.

3 comments

3 Comments

alexc935h ago

That old timer Bill sounds like the kind of guy who also knows not to trust the "max fill" line on a car's oil dipstick. It's funny how the right amount is almost always a little less than what the manual says.

adamgreen13h ago

Haven't we all learned that lesson the hard way? Bill's advice sounds like something a guy who's been riding since before indexed shifting existed would say. I fell for the same trap when I first started wrenching, torquing everything to the absolute max like I was assembling a space shuttle. Turns out the old timers know that torque specs assume everything is hospital clean and factory fresh, which it never is after a few months of road grit. I cracked a chainstay on an old Trek doing exactly what you were doing, so you got off easy with just a warning. Now I do the same thing Bill showed you, back it off maybe 10-15% and use a bit of grease on the threads. Your stem isn't going anywhere with that method, and you won't be buying a new fork anytime soon.

allen.ivan10h ago

Gotta disagree with you there, Adam. I think backing off torque by 10-15% is a quick way to strip threads or get a loose stem. Grease on threads changes the friction so you actually need less torque to get the same clamp load, which is why most modern torque specs say to do things dry. If you grease it and then back off even more you're basically guessing. I follow the manual, clean the threads with a rag, and set the wrench to the number in the book. Never cracked anything or had a stem slip. Maybe your old Trek had a weak spot from the factory or some corrosion inside the tube. I'd rather trust the engineers who designed the part than some guy who learned on bikes from the 80s.