The mount/demount head guides the bead over the rim flange while maintaining controlled clearance from the wheel.
Set radial and vertical clearance before rotation.
Protective inserts must be clean and intact.
Wheel geometry must be within machine capability.
Head-to-rim contact is not normal.
Head setup
Center and clamp the wheel, bring the head to the rim reference, lock it and confirm specified setback above and away from the flange.
Protective components
Replace worn plastic inserts. Embedded metal can scratch even when the protector appears present.
Unusual wheels
Reverse-drop-center, clad, forged and wide wheels may require different clamping or accessories. Confirm capability before proceeding.
Diagnostic reference
| Finding | Possible meaning | Next check |
|---|---|---|
| Head touches rim | Clearance wrong | Reset before rotation |
| Circumference scratch | Continuous contact | Inspect lock and insert |
| Bead catches head | Bead path wrong | Restore drop center |
Workshop procedure
- Inspect head and inserts.
- Center wheel.
- Set vertical and radial clearance.
- Lock and verify setback.
- Rotate slowly for clearance check.
Frequently asked questions
Should the head touch the rim?
No.
Why can a plastic protector still scratch?
It may contain debris or be worn through.
Can one setting fit every wheel diameter?
No. Flange and width differ.
Technical review edition · Published 17 July 2026.