This bearing supports the left hand side of the Bosch Gen 4 crankshaft. It will fit the Gen 4 Performance Line CX, Cargo and Speed motors.

Bosch Generation 4 motor BDU4xx.

Please see bearing identifier for bearing position.

Bearing will fit the Gen 4 Performance Line CX, Cargo and Speed motors.

Bosch Generation 4 motor BDU4xx.

This kit contains every bearing that is changeable in the Bosch Gen 4 motor. We don’t usually say this, but we would not recommend you tackle this motor without a lot of specialist tools and a strong mechanical engineering background.

This kit will fit the Gen 4 Performance Line CX, Cargo and Speed motors.

Bosch Generation 4 motor BDU4xx.

This is the bearing that supports the right hand (drive side) of the Bosch Gen 4 crankshaft. It will fit the Gen 4 Performance Line CX, Cargo and Speed motors.

Bosch Generation 4 motor BDU4xx.

This O-Ring sits between the front chainring (or chainring spider) and the lock nut. The O-ring is not fitted to all bikes, a new one should only be fitted if an old one is removed.

Bosch Generation 4 motor BDU4xx.

Please see bearing identifier for bearing position.

Bearing will fit the Gen 4 Performance Line CX, Cargo and Speed motors.

Bosch Generation 4 motor BDU4xx.

Please see bearing identifier for bearing position.

Bearing will fit the Gen 4 Performance Line CX, Cargo and Speed motors.

Bosch Generation 4 motor BDU4xx.

This kit is designed for the mechanic or engineer who has the tools to fix their motor but is undertaking this work for the first time. It includes the special tools required to remove the motor and all the seals to help keep your motor running smoothly once your work is done.

We have taken a genuine Bosch service / repair kit, removed the felt seals*, then added all the parts required for the rest of the motor. Left-hand crankshaft bearing, freewheel gear bearing, both transfer gear bearings, left-hand crankshaft O-ring and sprocket carrier O-ring, all 10 new circlips, the two thrust washers that sit each side of the main crankshaft drive gear, right hand crankshaft seal (this replaces the Bosch felt seals and is 100% waterproof), MudShield for main motor bearing protection, stainless steel bearing shield to offer limited protection for the left hand crankshaft bearing, crankarm puller, special lockring tool to remove front sprocket and a full set of new damping films to fit between the motor and frame. If you already have these tools, please see our Service kit +

We know that many of the motors we work on have suffered water damage to the other bearings used in the drive unit that are not replaced by fitting a Bosch service kit. We have now added these bearings and components to service the left-hand side of the motor too. This ensures you have everything you need to do the whole job properly.

We can fit this kit and bearings for you, and offer our own 12 month Performance Line Bearings parts and labour warranty. Fitting cost £350.50 + p&p

This kit is sold on the understanding that you have a basic level of technical expertise and does not include hand tools or INSTRUCTIONS.

*The felt “seals”, these are causing severe issues and motor failure in wet or dusty conditions.

Bosch Generation 2 motor BDU2xx (NOTE: Small chainring below).

This Kit is designed for the workshop mechanic that already has the ancillary parts required to overhaul this motor (grease, circlips, tooling etc.). Or the shop that just wants to know they have stock of each bearing on the shelf.

Kit includes every bearing required for the motor gears and drive train. Includes two crankshaft O-rings and drive sprocket O-ring.

Don’t forget to order genuine Bosch drive unit grease, Bosch seal grease, MudStop and right hand crankshaft seal separately if required.

Bosch Generation 2 motor BDU2xx (NOTE: Small chainring below).

This kit is designed for the mechanic or engineer who has the tools to remove the motor and is looking to do a full overhaul properly.

We have taken a genuine Bosch service / repair kit, removed the felt seals*, then added all the parts required for the rest of the motor. Left-hand crankshaft bearing, freewheel gear needle roller bearing, both transfer gear bearings, left-hand crankshaft O-ring and sprocket carrier O-ring, all 10 new circlips, the two thrust washers that sit each side of the main crankshaft drive gear, right hand crankshaft seal (this replaces the Bosch felt seals and is 100% waterproof) and a full set of new damping films to fit between the motor and frame.

We know that many of the motors we work on have suffered water damage to the other bearings used in the drive unit that are not replaced by fitting a Bosch service kit. We have now added these bearings and components to service the left-hand side of the motor too. This ensures you have everything you need to do the whole job properly.

We can fit this kit and bearings for you, and offer our own 12 month Performance Line Bearings parts and labour warranty. Fitting cost £315.00 + p&p

You may also want to consider our own Mega kit containing all you need to fully overhaul your own motor from scratch, and seal it to lessen the chance of failure happening again. Even the special tools to remove it are included.

This kit is sold on the understanding that you have a basic level of technical expertise and does not include hand tools or INSTRUCTIONS!

*We strongly recommend not fitting the felt “seals”, these are causing severe issues in wet or dusty conditions.

Bosch Generation 2 motor BDU2xx (NOTE: Small chainring below).

Genuine Bosch service / repair kit for the Bosch Gen 2 ebike motor. This part is available for you to buy and fit yourself. We would strongly recommend not fitting the felt “seals”, these are causing severe issues in wet or dusty conditions. Please disregard these felt seals and either fit nothing or our double lip rotary shaft seal. Bosch can not offer any warranty if you fit this part yourself.

If you decide against fitting this part yourself we would be happy to fit it for you. As a Bosch service partner we can honour the 12 month warranty and the fitting cost would just be £25.00 + p&p.

If you think your motor may need the left hand side looking at too, we offer the Bosch service kit + and our own Mega kit containing all you need to fully overhaul your own motor from scratch, and seal it to lessen the chance of failure happening again. Even the special tools to remove it are included.

Bosch Generation 2 motor BDU2xx (NOTE: Small chainring below).

Kit contains: Main motor bearing, left-hand and right-hand crankshaft bearings, both crankshaft O-rings, sprocket carrier O-ring (if required) and both outer 2mm thick circlips.

Don’t forget to order genuine Bosch drive unit grease, MudStop and right hand crankshaft seal separately if required.

Bosch Generation 2 motor BDU2xx (NOTE: Small chainring below).

Bosch Active Line, Performance Line & Performance Line CX main motor bearing.

We only use high quality bearings and ensure they have labyrinth seals for extra protection from water ingress.

DO NOT fit bearings with “MAX” designation, these bearings are designed as pivot bearings and not as a rolling bearing. They will fail prematurely in a motor application.

Bosch Generation 2 motor BDU2xx (NOTE: Small chainring)

This bearing, has been specially manufactured to fit the Bosch Active / Performance Line / CX crankshaft.

Bosch Generation 2 motor BDU2xx (NOTE: Small chainring)

Will replace Bosch Active / Performance Line / CX left-hand crankshaft bearing.

Bosch Generation 2 motor BDU2xx (NOTE: Small chainring)