Repair guides › Frame & Fork
Use a torque wrench
The backbone. Everything bolts to it, and its geometry decides how the bike fits, steers and how wide a tire it clears. 6061 aluminum tubes TIG-welded into a front triangle (top, down, seat and head tube) and a rear triangle (seat stays and chainstays). Threaded inserts (nutserts) take racks, fenders and bottle cages. Aluminum does not rust, but it can crack, especially near welds, and it does not bend back.
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Tools
- 1/4" click torque wrench (about 2–17 Nm) + bits: Pro Bike Tool 1/4 inch drive click torque wrench set (2.2–16.9 Nm) ($$)
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Steps
- Find the number: it’s printed on the part next to the bolt (like “5 Nm max”) or in the job’s torque table. If they differ, the part’s number wins.
- Set the wrench: unlock it, turn the handle until the scale reads your number, then lock it. Use the right bit and push it fully into the bolt.
- Pull slowly and smoothly on the handle (not the head), at a right angle to the wrench, until it clicks once. Stop at the click: don’t keep pulling.
- Several bolts on one part (a stem, a seatpost clamp): tighten in small steps, crossing between bolts, then go round once more at the final number.
- Never use it to loosen bolts, and never drop it: both throw it out of calibration.
- Stay in its range: a small 2–17 Nm wrench can’t do 35 Nm pedals or 40 Nm lockrings. That’s the bigger 3/8" wrench, later in the story.
- When you’re done, turn the setting down to its lowest number for storage so the spring stays accurate.
Signs it needs doing
- Creaks that follow you even after the BB, pedals and seatpost are greased
- Hairline crack or paint flaking in a line at a weld
- Rear wheel no longer sits centered (bent dropout)
- Dent in the down tube or top tube