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Brose Motor Servicing


Both the original Brose S&T (Gen-1) motors and the latest Brose SMag motors are very similar internally, the motor casing material and weight is the big difference. When diagnosing or quoting for service or repair, please refer to the questions and answers below for a guide to what the issues may be. 

The Brose motor is currently the best motor to service. This motor can be upgraded with stronger belt, stronger sprag (clutch) bearings and fitted with an additional single lip rotary shaft seal, to stop water ingress into the crankshaft, and additional waterproofing... go to our eBike Motor Upgrades page for more information and full pricing.

Brose Belt Replacement ($450.00)

  • Motor Belt Casing removed and cause of belt failure diagnosed (dependent on the cause of the belt failure, we may notify the motor owner to discuss further, as the belt failure is not just from wear or high load)

  • Planetary Gears inspected, cleaned and regreased with a specialist nylon lubricating/silencing grease 

  • Uprated latest generation Brose OEM carbon fibre belt installed, belt lubricated with specialist lubricant

  • Belt tensioner /pulley assembly cleaned, serviced and refitted

  • Motor Belt Casing refitted with new gasket and screws

  • Belt is correctly tensioned to 0.25Nm, and then tested

  • New external right-hand crankshaft seal fitted

  • Motor is bench tested to check proper belt operation

Brose Full Bearing Overhaul ($714.50)

  • All internal drive train parts removed for thorough cleaning and inspection

  • All drive train bearings, and other critical bearings, will be removed and replaced with original or better

  • New seals and O-rings fitted

  • Where parts are found corroded, failed or worn beyond acceptable limits, the owner will be contacted to discuss options and pricing

  • Specialist greases are applied to all relevant surfaces/parts to maximise protection from water ingress and wear

  • No belt replacement is carried out with the Full Bearing Overhaul

  • Motor is reassembled and tested

Brose SMag Bearing Overhaul+Upgrade ($942.00)

Full bearing/seal overhaul + Brose Upgrade, price reduced where individual bearings not required to be replaced.

  • All internal drive train parts removed for thorough cleaning and inspection

  • Main Crankshaft drivetrain bearings removed and replaced

  • Uprated latest generation Brose OEM carbon fibre belt installed, belt lubricated with specialist lubricant

  • Uprated motor and crankshaft drive pulley sprag clutch bearings

  • Crankshaft lip seal added to stop water ingress to crankshaft needle bearing (not found on std Brose build)

  • Genuine Brose bearing cover seal (r/h crankshaft)

  • Specialist long-life waterproof grease packed between outer bearings and motor covers. (helps stop water pooling around outer bearings)

  • External X-ring crankshaft seal added

  • Compromised ECU cover screws sealed to stop water ingress into ECU, circuit board (Gen-1 T/S/TF only)

  • Motor is reassembled and tested

Frequently Asked Questions

Does my Brose motor need regular service?

Brose motor should have its drive belt changed after 15,000kms. The rest of the motor is not designed to be serviced and should only be repaired if it starts to fail.

Motor works on walk assist but will not work when I pedal?

This is usually caused by failure of the torque sensor and should be sent to us for torque sensor replacement.

My crank is stiff to turn backwards?

This is normally the first sign that your motor crankshaft needle roller bearing is failing due to water ingress or dust ingress, or a combination... resulting in corrosion or a build-up of dust or grit.

My Brose motor makes cracking, popping or screeching sounds?

A fairly sure sign that one of the two motor clutch bearings are failing. Definitely worth getting this investigated as it will result in complete loss of drive.

My motor runs on when I stop pedalling?

This can be one of two reasons:

  1. The crankshaft needle roller bearing is badly seized, breaking up or contaminated. This causes the crankshaft and sprocket carrier (torque sensor) to become one or very stiff to turn independently of each other.

  2. The clutch bearing is starting to fail and the ‘sprags’ (small feet that lock the bearing) are beginning to jam or stick. Both these scenarios allow the motor to continue to add power because it can only see that the crankshaft is still turning. This may happen right up to the cutoff speed.

Specialized Levo Kenevo Brose Gen1 motor aluminium
Brose S & T (Generation-1)​

The first generation Brose motors with the original aluminum casing. This is a very strong motor, very quiet and very reliable with various builds of 50Nm, 70Nm and 90Nm torque deliveries.

Brose SMag Specialized Levo Kenevo Brose Gen2 Gen3  motor magnesium
Brose SMag (Generation-2)

The second generation Brose motor is recognisable by its smaller black magnesium casing. This is an excellent, powerful yet natural feeling motor with 90Nm of torque, although it did have some earlier issues with the first 2019-2020 motor builds. Since that time, the belts have been upgraded to much stronger material and design, and the firmware has been updated to remove unwanted "torque spikes" that were damaging to both the belt and sprag bearings. It is now a very reliable motor, although water ingress is still an issue, like many eBike motors today.

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