Level of difficultyfor talented hobby mechanics
Tool
- Centring stand
- Centre key
- socket spanner if necessary or
- Wheel-specific centring tool
- Centring clamp
Auxiliary materials
- Crepe or insulating tape
Instructions: Tensioning road bike spokes & centring lateral impacts
1. clamp the wheel in the centre of the centring aid, set the centring pointer(s) at a distance of one millimetre from the rim. Turn the wheel and observe the light gap. If this is still large in the area where the rim is closest to the pointer, move the pointer further in until it almost touches this point.
2. slide a dial gauge until the probe is inserted approximately in the centre of its measuring range. Find the point that is centred between the large deflections to the left and right. You can recognise the largest deflection by the fact that the needle then changes direction. Turn the zero position of the dial gauge to this pointer position.
3. turn the rim to the point of greatest deflection. Mark several deflections accordingly. Divide the deflections into those that go to the right and those that go to the left. Centring in one direction only can result in the rim moving off centre and no longer being centred in the frame or fork.
4. pull a spoke outwards with one finger or press two spokes of one side together and observe the gap on the pointer. If the rim moves in the desired direction, you have found the side whose spokes you need to tighten a little more.
5 Grasp the spoke so that your thumb is pointing towards the hub. The fingers of the half-closed hand point in the direction of rotation, the thumb in the direction in which the nipple wants to move. As it is held by the rim, it pulls the spoke tight instead.
6. where the rim is closest to the pointer, you must tighten the spoke on the opposite side - a maximum of half a turn. The neighbouring spokes on this side are also tightened by about a quarter of a turn. Then check the concentricity of the entire wheel.
7 Centring is a game of patience; feel your way gradually in small steps and make sure that you increase the tension of all spokes on one side in the area of lateral distortion. Avoid tightening a single spoke too much, as this could lead to a height distortion.
8 Check the entire impeller again and again. Adjust the pointers tighter and tighter. Work evenly on all side lays to get the wheel in the centre between the pointers. Tighten the spokes until the deflection is only a maximum of one to two tenths of a millimetre on each side.
9. retensioning causes the spokes to twist. as a precaution, turn the nipples an eighth to a quarter of a turn more than necessary during the final centring round and then back again a quarter of a turn. Alternative: Press opposite spokes together in pairs in turn (image).
Special shapes for road bike wheels
Aerodynamically shaped blade spokes
These spokes should be kept in a streamlined position when centring and not twisted unnecessarily. Use a centring aid in the form of a slotted block to secure the spokes against twisting.
Nipples for Mavic wheels
Some Mavic wheels have a special nipple clamping method in which a retaining screw is screwed into the rim. Use the original tool supplied for centring. The centring direction remains as usual. With some Shimano wheels, the cap screw must be turned the other way round.
System wheels with nipples hidden in the rim well
On some system wheels, the nipples are hidden inside the rim. In this case, the tyre and rim tape must be removed, then the nipples can be accessed from the rim bed using a socket spanner. Centring then works in the same way as with conventional wheels, the tool is turned clockwise.
Tips for centring road bike wheels
Spoke or bearing?
First check for possible bearing play in the hub. Secure the wheel in the assembly stand and push the rim back and forth at several points at right angles to the direction of rotation. Slight juddering is caused by play in the bearings. If the wheel feels generally flexible, this is due to the elasticity of the rim and spokes.
Perfect fit
Only use high-quality tools - this also applies to such a supposedly simple part as a nipple tensioner. Roughly punched sheet metal tools, spanners with too small a contact surface or too large a spanner width can damage the square of the spoke nipple.
Measurable
With a dial gauge from the tool market, which is attached to the truing stand using a magnetic base, you can make your truing work easier. If you centre wheels frequently or are spoking wheels, it is worth using a truing stand with drag indicator dials that show fine deflections in magnified form.
Balanced
Check the wheels for possible imbalances by letting them swing repeatedly in the truing stand until the heaviest point is at bottom dead centre. Then fit the spoke magnet of the speedometer at the highest point so that the wheel runs more smoothly at high speeds.
