Short answer: buy two wrenches. A motorcycle service manual will specify a clutch cover screw at around 10 Nm and a rear axle nut at over 100 Nm on the same page, and no torque wrench is trustworthy across a 10:1 span. The usual split is a 1/4 in inch-pound wrench for everything small and a 3/8 in foot-pound wrench for everything structural.
The three bands on one motorcycle
| Band | Typical fasteners | Drive that suits it |
|---|---|---|
| Roughly 5 – 20 Nm | Case covers, bar clamps, mirrors, reservoir caps | 1/4 in, marked in in-lb or Nm |
| Roughly 20 – 60 Nm | Caliper bolts, sprocket nuts, engine mounts | 3/8 in |
| Roughly 60 – 140 Nm | Axle nuts, swingarm pivots, steering stem nuts | 3/8 in at the top, or 1/2 in |
Those are bands, not specifications. The authority for any individual fastener is your model's service manual, and on a motorcycle the consequences of guessing are more direct than on a car.
Units: the one that catches people out
Motorcycle manuals are almost always in Nm. US wrenches are usually marked in ft-lb or in-lb. One Nm is about 8.85 in-lb; 1 ft-lb is about 1.36 Nm. The expensive mistake is applying 10 ft-lb to a 10 Nm fastener — that is 13.6 Nm, 36% over, and on an aluminum case cover it strips the thread. Either buy a wrench that reads Nm directly, like the electronic pick above, or convert on paper before you set anything.
Why head size matters on a bike
Motorcycles have no spare room. A 1/2 in drive head is often physically too large to reach a caliper bolt inside a wheel, or a sprocket nut behind a chain guard. A 3/8 in wrench with a fine-tooth ratchet does the same job in the space available, and a 1/4 in wrench with a small swing arc reaches into the engine cases. This is a real reason to prefer the smaller drives even where a bigger wrench would technically be in range.
Look after them, or the numbers stop being true
Click wrenches get wound back to their lowest setting after every use. Split-beam wrenches do not need it, which is the whole argument for the type — see click vs digital and how to use a torque wrench for the handling detail that keeps a wrench honest.