I used to think torque wrenches were overkill for bikes until I snapped a bolt

I was always the type to just tighten things by feel on my old mountain bike. But last month I tried to swap my crank arm and used a regular ratchet. Snapped the bolt clean off after about 30 seconds of turning. Took me two hours and a trip to the hardware store to get a bolt extractor set. Now I keep a cheap torque wrench in my garage and actually use it for anything with a specified number. Has anyone else learned this lesson the hard way with a specific part?

2 comments

2 Comments

noahhall25d ago

Feel like you do, most of us learned that way.

bennett.claire24d ago

Noah, I get where you're coming from, but it's not just about feel. Feel is how you strip threads in aluminum frames or overtighten a stem bolt until the handlebar slips. I did the same thing on my old road bike with the seatpost clamp, cranked it down like it owed me money, and ended up with a creak that took weeks to figure out. A torque wrench is more about consistency than strength, you know? Like, your hand can feel "snug" fine one day and then overpower a tiny 5mm bolt the next. That crank arm bolt is a perfect example, most of those are only supposed to be like 35 to 40 Nm, and a ratchet makes it way too easy to blow past that. Did you end up checking the other bolts on that bike after the extractor set?