Multipoint locking system (uPVC / composite)
One cylinder and one handle drive hooks and rollers at three or more points along the door edge through a gearbox. The handle must be lifted to throw the bolts, which is the fact that breaks most naive retrofit motors.
Also called: Multipoint lock · MPL · Gearbox lock · Hook and roller lock
Anatomy
- Gearbox (centre case) holding the cylinder and spindle
- Extension strips above and below carrying hooks or rollers
- Full-length handle
- Oval or euro cylinder depending on door age
Parameters to measure
Measure in this order: Centre distance, spindle-to-cylinder (Entfernung / PZ) → Handle fixing screw spacing → Backset (Dornmaß) → Cylinder total length and halves (e.g. 35/35)
| Parameter | Typical values | Tolerance that still fits | How to measure |
|---|---|---|---|
| Centre distance, spindle-to-cylinder (Entfernung / PZ) | 92 mm most common; 85 mm and 72 mm also exist | None | Spindle centre to cylinder centre on the gearbox face. |
| Backset (Dornmaß) | 35 / 40 / 45 / 50 mm | — | Door edge to cylinder centre. |
| Handle fixing screw spacing | 205 mm or 215 mm screw centres | None for handle replacement | Top screw hole to bottom screw hole. |
| Faceplate width × length | Extension strip width 16 / 20 / 24 mm | — | Measure the strip width on the door edge. |
| Cylinder total length and halves (e.g. 35/35) | Oval cylinders 62–92 mm total; euro profile on newer doors in 5 mm steps | Exact | Remove the central screw, take the cylinder out and measure both halves. |
Retrofit architectures that work
- Motor on the thumb-turn — A geared motor clamps over the existing cylinder body on the inside of the door and turns the thumb-turn (or a key left in the cylinder). The lock case, cylinder, faceplate, keys and door prep are all untouched.
- Electronics integrated in the cylinder — The cylinder itself is replaced by a cylinder with the motor, battery and radio inside. The outside keeps a mechanical keyway; the inside is a motorised knob. Nothing else on the door changes.
The motor must rotate the cylinder enough to retract the hooks AND the user must still lift the handle. Designs that ignore the lift step produce a lock that appears to work in the lab and fails on every real door.
Related standards
EN 12209 · EN 1303 · TS 007 · EN 1634-1
Reference devices
Recorded as engineering examples, not endorsements.
- Nuki Smart Lock — Motor on the thumb-turn ✓ verified
- Yale Linus L2 — Motor on the thumb-turn ✓ verified
Questions
How do I find the centre distance without removing the handle?
Look at the gearbox face through the handle opening, or measure from the spindle centre to the cylinder centre with the handle off — usually 92 mm on a British door.
Is the gearbox replaceable on its own?
Yes, and it is the part that fails first. Match centre distance, backset, strip width and the number of locking points.