If you are replacing your own bearings, you can find the bearings you need and their part numbers in our bearing identifier. These parts can then be found in our shop. If you need other engine parts, please contact us and we will be happy to help.
Generation 4
- Gen 4 Performance Line CX 75 Nm mountain bike engine. Later upgraded to 85 Nm in 2020 - still on the programme.
- Gen 4 Speed Line and Cargo Line engines also exist, but essentially all engines are designed specifically for a particular function and battery consumption.
Does your Bosch Motor need regular maintenance?
Bosch motors are not designed to be serviced and should only be repaired if they become faulty. The motors are sealed and, when kept dry, will run for over 80 000 km without any problems.
My Bosch engine sounds a bit rough, should I keep driving it until it stops working?
No! If you hear your engine making extra noise while driving, it's already too late! The bearings are damaged, the balls inside the bearing wear out quickly and as they wear they shrink and this causes the bearing seals to lift up from the inner/outer cavities, allowing water or dirt to enter directly into the engine! All Ebike motors fail in this way. Don't ignore the noise level changes in your engine as there is a limit to what can be repaired.
Why do bearings fail, are they of poor quality?
The bearings fitted to most Bosh motors are of very good quality and well sealed, but even if a bearing is classified as “sealed”, it is not waterproof! At best, they are water and dust resistant. This is true for 99 of the Ebike motors on the market with the %.
Why do manufacturers not seal Ebike engines from water and from dirt?
Sealing the engine at the design stage would be very easy, but seals increase drag and battery consumption. It would be a competitive disadvantage for a manufacturer to launch an engine that achieves 2km less distance than its competitor.
My engine is squeaking whether it's the bearings
- The bearings will thunder, grind occasionally or seize. They usually do not squeak. The creaking is usually caused by one of the following:
- Loosened engine bolts. This causes the aluminium engine frame to creak against the aluminium frame.
- The seat pan creaks in the frame (most sounds travel along the frame and into the engine area).
- Crank loose
- If a new cage and front wheel are installed, (Gen 3 and 4) check the front wheel bolts
- The pedal makes noise
- Suspension joints make noise
- Rear wheel axle loose
Can I get an additional gasket for my Gen 4 engine?
There is currently no additional protection for the Gen 4 engine, but this engine already has pretty good seals installed when new. They will need to be removed and re-lubricated from time to time, depending on driving conditions, your cleaning habits, weather conditions, etc.
Will the tuning damage or wear parts on my Bosch motor?
No damage to the engine has been observed during maintenance due to the use of the deceleration device.
What can cause damage or wear to my engine besides water and dust?
Slightly higher wear rates have been observed in engines used at low pedal speeds and high gears, where the engine is running relatively slowly and trying to increase power. Pedalling at a higher pedal speed is definitely better and more efficient for the engine. Damage can be caused by pedal shocks and collisions, but that's it! Engines are generally very durable if you take care of them.
When should I take my engine in for service?
Bosch motors are maintenance-free and last for thousands of kilometres when kept dry.
Can I get more power from the engine?
Not at the moment.
Can I change the engine to a newer model?
In some cases this would be possible, but not as easy as it sounds. Engines can vary greatly from model to model, size, comb type, mounting bolt size and location, plug type and location, etc. These can all change, as can compatibility with older batteries and controllers. In general, at the end of the day, it is cheaper and easier to buy a new bike at this time.
