Sprag Clutch Bearing for the Pulley of Brose Alu S / Mag S Motors

One-way clutch, also known as a sprag bearing, installed inside the pulley or large belt-drive transmission gear of Brose motors.

This component transmits force in one direction while allowing free rotation in the opposite direction. When the clutch is worn or damaged, the motor may experience loss of internal drive, cracking or crunching noises, loss of engagement or free rotation without correctly transmitting force.

This is the metal version with a metal cage, offering a more robust alternative to the plastic-cage clutches used in some original motor versions.

Compatible with

Brose Alu S
Brose Mag S
Brose Drive S
Brose Drive T
Brose S-Mag
Specialized Turbo motors equipped with an equivalent Brose drive unit

This clutch may also be listed as a repair part for Brose Alu C, T, TF and S motors, as well as Brose S-Mag motors, provided that the motor uses this type of clutch in the transmission pulley. Before purchasing, we recommend checking the removed component or contacting us to confirm compatibility.

Specifications

Part number: PLB20126
Type: one-way clutch / sprag bearing
Location: pulley or large belt-drive transmission gear
Version: metal
Dimensions: 35 × 43 × 11 mm
Application: internal repair of Brose motors
This is not the crankshaft clutch. The correct part number for that position is PLB20127.

Common symptoms of failure

A damaged pulley clutch may cause:

Internal cracking or crunching noises
Loss of drive
Free rotation or intermittent engagement when force is applied
Incorrect engagement between the pulley and the internal transmission
A feeling that the motor is not transmitting assistance correctly

Installation

To replace this clutch, the pulley or transmission gear must be dismantled. In many cases, the large pulley bearing must first be removed and then correctly reinstalled after replacing the clutch.

The pulley must be heated in a controlled manner to remove the gear race without damaging the housing. This is a technical repair that requires suitable tools and experience with Brose motors.

Important information about grease

One-way clutches require a grease specifically designed for this type of component. Standard greases, low-friction greases and greases containing additives such as Teflon, ceramic, MoS₂ or other solid additives must not be used, as they may cause the clutch to slip under load and fail prematurely.

We recommend using a grease specifically designed for Brose motor clutches.

BiciFix note

This product includes only the pulley one-way clutch, part number PLB20126. It does not include the complete pulley, the large pulley bearing or the crankshaft clutch.

For a complete motor repair, it may also be necessary to replace other bearings, the belt and the PLB20127 clutch, depending on the condition of the motor.