Did you tighten the axle well at the horn? The horn must only have minimal lateral play. To achieve this, the two screws must be tightened strongly. So that the lateral play is almost eliminated and the horn can still be moved smoothly (without noticeable friction). At best, you can extend the Allen key with the blocker.
- Tightening must be done evenly on both sides. To do this, switch sides several times and tighten only a quarter turn at a time. Then check the remaining lateral play each time.
- Under no circumstances should you overtighten and pinch the spacer rings. This leads to an unpleasant crunching noise during training. If in doubt, it is better to leave a minimal amount of residual play. You can always add another quarter turn at a later time if necessary.