Always use a torque wrench on your bike. Modern bicycles use lightweight aluminum and carbon fiber components that can crack or fail from over-tightening. The torques listed here are typical — always follow the manufacturer's spec printed on the component.
| Component | Bolt Size | Torque (N·m) | Notes |
|---|---|---|---|
| Stem faceplate bolts | M5 | 4–6 | Tighten evenly in X pattern |
| Stem steerer clamp | M5–M6 | 5–8 | Carbon steerers: max 5 N·m usually |
| Seatpost clamp | M5–M6 | 4–7 | Carbon post: use carbon paste, lower torque |
| Saddle clamp bolts | M6 | 8–14 | Varies by seatpost design |
| Brake caliper mount | M6 | 6–8 | Disc brake flat mount |
| Brake rotor bolts | T25 | 2–4 | 6-bolt: use threadlocker |
| Crankset bolts | M8 | 12–14 | Shimano Hollowtech II pinch bolts |
| Chainring bolts | M5 | 5–9 | Direct mount vs 4/5 bolt varies |
| Derailleur clamp | M5 | 5–7 | Front and rear |
| Bottle cage bolts | M5 | 3–5 | Into frame rivnuts |
| Pedals | 9/16" or M14 | 30–35 | Grease threads, hand-tight + 1/4 turn |
| Bottom bracket | Varies | 35–50 | Threaded BSA type |
Reduce torque by 20–30% for carbon parts compared to aluminum. Carbon fiber doesn't deform like metal — it goes straight from holding to cracking. A carbon seatpost or handlebar that looks fine can have invisible internal damage from over-torquing that leads to sudden failure while riding.
Use carbon assembly paste (gritty friction paste) on carbon-to-carbon and carbon-to-metal interfaces. It increases grip so you can achieve the same clamping force at lower torque. This is not optional — it's a safety requirement.
Never use grease on carbon. Grease reduces friction, which means you'll over-tighten trying to get the component to hold, which means you'll crack the carbon.