Tools you should have at home
Most of the adjustment work on handlebars and saddles can be done by anyone, and the necessary arsenal of tools is manageable. Here is an overview of what you should have at home.
- Hexagon socket or Torx spanner, depending on the model. The "Y" tool combines the most commonly used sizes 4, 5 and 6 millimetres and saves time on simple jobs; the tool is also available for Torx screws.
- A maximum torque is specified for most connections, which should not be exceeded. A small torque spanner (up to approx. 10 Nm) is therefore mandatory.
- Assembly paste (also known as carbon paste) increases the friction between the parts with small particles and also protects against corrosion. A must for carbon components, but also helps with aluminium handlebars.
- Grease should be applied to all screw threads; it also protects aluminium seat posts from seizing up in metal frames. Keep away from carbon parts!
- Spirit level as an aid for the position of the saddle and handlebars; a tape measure is also useful for some work.
The most important torques
- Gear lever 5-6 Nm
- Handlebar clamp 4-6 Nm
- Stem cap 1-2 Nm
- Stem clamp 4-6 Nm
- Seat post 3-5 Nm, varies greatly depending on the clamping principle
- Saddle 5-7 Nm (with two screws)
General professional tips
- Use the torque spanner to develop a feel for how tight the individual screws need to be tightened. This avoids mistakes if you only have a mini tool to hand when travelling.
- Do not use corroded or damaged screws. Grease all screw threads, including under the screw head. This reduces the required torque and sensitive components will then clamp securely.
- Some screws are factory-fitted with threadlocker - in this case the thread is not greased. Only apply a little under the screw head.
- Always keep safety-relevant clamps (handlebars, shifters, steerer tube) and carbon parts free of grease! If in doubt, use assembly paste.
- Clamp connections settle after some time and the clamping force of the bolts decreases. You should therefore check the torque and the tightness of the parts after around 200 to 300 kilometres.
The stem
The task of the stem is straightforward, but details are important for a secure connection to the steerer tube. We show you which ones.
Snug fit
Low torques are sufficient on the steerer tube if the stem sits precisely and without play on the steerer tube. Apply a thin layer of assembly paste to the clamping surface, then tighten the bolts lightly and evenly before tightening to 4 to 5 Nm (or up to the specified torque).
Control
The clamping slot must not be pulled together completely or at an angle. You can check the tight fit by clamping the front wheel between your knees and trying to turn the stem using the handlebars as a lever. You can check the play in the steering bearing by pulling the front brake and moving the wheel forwards and backwards. The fork must not move in the head tube and the bearing must be able to rotate without resistance.
Fitting the stem: Professional tips
The play in the steering bearing must be checked again after tightening the stem and readjusted if necessary. The clamping force can cause the stem to spread and exert pressure on the bearing.
Look for a good expander. It needs a robust mechanism and grippy clamping surfaces, and it should also reach at least as far as the lower edge of the stem in the steerer tube. Simple claws may only be used with steerer tubes made of steel or aluminium!
Spacers place the handlebars higher or lower on the bike. More than 35 millimetres of spacers under the stem are not advisable, 5 millimetres above the stem ensure that the stem has the full clamping force.
Sawing off the steerer tube - what you need to consider
If the handlebars are to be mounted lower, the steerer tube may need to be shortened by the appropriate amount. Only carry out this step if you are absolutely sure and have the right tools. You will need an iron or carbon saw with a fine blade and a cutting guide that is clamped onto the steerer tube. Saw with little pressure and very carefully, especially at the end of the cut. You can seal the cut surface with a little epoxy resin.
Jens Klötzer
Editor
