Overseas Orders

Refer to Worldwide partners page Click for More Info

FAQs – Bosch

All Bosch motors are very different internally. When diagnosing or quoting for repair, it’s important for us to know exactly which motor you have. It’s very common to believe you have a Gen 3 motor when you actually have a Gen 2, Hopefully this page will help you correctly identify your motor.

Which generation is my Bosch motor?

Generation 1

Gen 1 Bosch “Classic” Line 50Nm (2011 – 2014) Mostly fitted to road bikes, but used in a few early EMTB’s such as Moustache and Haibike.

Bosch Gen 1 “Classic”

Generation 2

Bosch Gen 2 Performance Line
Bosch Performance Line CX

Generation 3

Bosch Gen 3 Active Line
Bosch Gen 3 Active Line (Note large chainring)

Generation 4

Bosch Gen 4 Performance Line CX

Does my Bosch motor require regular service?

Bosch motors are not designed to be serviced and should only fixed if they start to fail. The motors are sealed for life and if kept dry will do in excess of 50,000 miles (80,000km) without problem.

My motor sounds a bit rough, should I just keep riding it until it stops?

No! If you can hear your motor is noisy while riding, it’s already too late! The bearings have failed, the balls within the bearing will be wearing rapidly; as they wear they get smaller, this causes the seals of the bearing to be lifted from their seat’s allowing water or dirt straight into the motor! All ebike motors fail like this when the bearings are in distress, and it’s a cascading effect. Don’t ignore any change in noise level from your motor, there are limits to what can be repaired.

Why do the bearings fail, are they bad quality?

The bearings fitted to most Brose motors are extremely good quality and well sealed, but although a bearing is classed as “sealed” it is not waterproof! They are at best water and dust resistant. This is the same for 99% of the ebike motors on the market.

Why don’t they seal ebike motors against water and dirt?

It would be very easy to seal a motor during design stage, but seals add drag and drag equals battery consumption. It would be commercial suicide for a manufacturer to release a motor that achieved 1 mile less battery range than their competitor.

My motor is creaking, are the bearings failing?

Normally. Bearings tend to rumble, grind, crank and crunch intermittently or seize. They don’t creak. Creaking is usual caused by one of the following:

Can I get any extra seals for my Gen 4 motor?

There is currently no extra protection for the Gen 4 motor. but there are already some pretty good seals on this motor. They do need removing and re-greasing from time to time and this will depend on your riding terrain, cleaning habits, weather conditions etc.

    Your Cart
    Your cart is emptyReturn to Shop