Torque is a physical quantity in classical mechanics and has a special meaning when tinkering with bikes: It describes the measured quantity with which certain components may be tightened, for example when carbon components such as handlebars are attached to the stem or clamps for the shift and brake levers are attached to the handlebars. A torque can twist (torque) a body or accelerate or brake its rotation.
The unit of measurement for torque is the Newton metre (Nm), the formula symbol for torque is M. If a force F acts vertically on a lever arm of length r, the amount of torque results from the length of the lever arm multiplied by the amount of force: M = r x F.
Torques on the mountain bike:
To achieve the permitted 6 Nm torque for a stem bolt, for example, you would have to put 0.6 kilos of weight on a one metre long lever. Because this is difficult to achieve when tinkering, there are torque spanners that crack or tip briefly when the torque is reached. Especially with carbon and titanium parts on stems, handlebars and seat posts, you should definitely work with a torque spanner. If you tighten the bolts too tightly, the carbon fibre structure may be damaged and suddenly break later. And a broken handlebar can result in serious injuries.
Stefan Frey
Editor
