Upgrading the BROSE engine

The eBike Motor Centre has noticed that cases of Brose motorcycle failures have been widely reported and discussed on forums and social networks around the world. They could also see from their own experience and the large number of Brose bikes that have passed through their workshop that there were some issues to be addressed, especially when using eBikes on trails and forest paths. Although Brose has tried to deal with some of these problems, this does not help those that are outside the warranty period. So they decided to do something about it!

I can now offer upgrades for all Brose engines. This includes the following:

  • Improved, thicker and stronger Brose carbon drive belt.
  • Improved reinforced drive shaft bearing.
  • Improved reinforced drive shaft bearing on the belt side.
  • A seal on the outside of the drive shaft that prevents water from entering the needle bearing on the shaft and prevents rust damage and premature failure of the needle bearing on the shaft.
  • Original Brose bearing cap seal for right needle shaft bearing (not fitted until 2017).
  • A waterproof, long-life lubricant that is installed between the outer bearings and the engine covers (this helps prevent water from pooling in these areas and seeping into the outer bearings).
  • We also fit an external X-ring seal on each side of the shaft to further prevent the possibility of water ingress into the engine.
  • Remove the two screws of the ECU (Engine Control Unit) cover and seal them to prevent water from entering the ECU.
  • Finally, protect the electrical plugs of the motor to prevent corrosion and capillary ingress of water through the wires into the ECU.

Brose engine upgrade price

The price is based on the engine being in good working order, with no other parts or repairs needed. If I open your engine and find any problems that require attention, such as a worn or defective bearing etc., I will contact you with a price to repair these problems before we proceed with any upgrade work.

  • *BroseT €191.55 incl. VAT
  • *BroseS €191.55 incl. VAT
  • *BroseTF €191.55 incl. VAT
  • *BroseS-Mag €215.77 incl. VAT (if 2020 belt not fitted)
  • *BroseS-Mag €122.98 incl. VAT (if 2020 belt already fitted)

If you want extra reassurance or want your Brose engine to be as strong, watertight and reliable as it currently is, simply send us your engine. This upgrade is also a must for those of you who use your Brose Electric Bike for racing or competitions.

* Return shipping costs

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Questions and Answers

Questions about bearings

Can I relubricate the bearings?
The bearings in all electric bike (ebike) motors are already greased and should be good for the life of the motor. If the bearing is damaged by water or dirt, it will be permanently damaged and no amount of grease will help. It will only make the inevitable damage go away.

Why are ebike bearings so bad?
Bearings for ebikes are often high-quality, oversized bearings. Much bigger and stronger than they should be. It’s not the bearings fault, it’s usually the environment the bearings are facing.

But what if I just keep driving, loud bearings do last a long time, don’t they?
No, they don’t last long if it’s an e-bike engine that’s been driven in harsh conditions or washed regularly. Let’s look at an example of a crank bearing: As the bearing wears, the balls in the bearing become smaller, allowing the bearing to move, and it is usually felt as play in the crank. This ‘play’ lifts the bearing seals out of place, allowing water and dirt to enter the bearings, leading to further problems. If you hear the bearings while driving, it’s already too late!

What type/quality of bearings do you use?
We always try to use original or better bearings. There are cases where a manufacturer may prefer to use a bearing with less friction rather than a sealed bearing. For example, if we have noticed that a particular bearing often fails in the field, we will replace it with a better sealed bearing.

Engine repair and shipping issues

How much will it cost to repair my engine?

As a very rough guide for most e-bike engines, the lowest price is around 60 to 80 euros, and the worst case scenario would normally be 250 to 350 euros. (Not usually, but if internal parts need to be replaced, this cost can be exceeded. Again, you will be informed before any work is carried out).

What is the current implementation time?

We are currently working with a timeframe of 10 to 12 working days from the moment your engine arrives with us.

Who should I use to ship my engine?

The courier you choose to send your engine to us is entirely up to you.

What is involved in a comprehensive renovation?

Your engine will first be tested, then all internal parts of the drive train will be removed for ultrasonic cleaning and inspection. All bearings on the drive train will be removed and replaced with original or better ones. New grease will then be applied to all relevant surfaces, and additional specialised lubricants may be used to protect against wear or water ingress. New gaskets, O-rings and clamps will be installed. The engine will then be reassembled. (If any part is worn, you will be informed before we proceed and install the new part).

What is included in the service/repair?

Your engine is disassembled and inspected, then we contact you with a report and price before we proceed with any work. Usually only parts or bearings that have failed are replaced. Often with certain makes of engine we need a complete overhaul.

General questions about the engine

My engine squeaks, is it the bearings?

Bearings do not usually squeak. When people bring their bikes to us with these sounds, they are the reasons we have so far found for the squeaking or popping of engines of all kinds: loose engine bolts, (causing the engine to squeak against the frame), loose chainring bolts on the spider, loose crank arms, squeaking pedals, squeaking seat stays, squeaking rear suspension links, loose front chainring (usually the wrong type of chainring for a Bosch or worn spider mounts for a Yamaha). Loose spokes in the rear wheel or squeaking rear wheel axle (when we say loose we don’t mean they are not tight, but not tight enough to prevent squeaking).

Is my engine waterproof?

The answer is probably no. At the moment, it would be commercial suicide for e-bike motor manufacturers to seal the motor properly, as this would lead to added friction and reduced battery range. This does not look good on comparison charts when people are deciding on buying an e-bike. Most current bike motors rely on dust seals rather than any special seals against water. This situation is good enough for most road bikes, but bikes used off road will be problematic.

How can I protect my engine from water ingress?

There are customised products for some engines, but not all. There are also some simple steps that can help. Store the bike upright, in a dry place. If you are transporting the bike behind a vehicle, make sure the engine is covered if the roads are wet. Do not direct water spray at the engine, especially at the crankshaft area. Do not cross any water deeper than the bottom of the engine.

If water gets into my engine, will it dry out?

The Yamaha has a small breathing membrane that allows the engine to dry out over time. If there is more than a drop of water, the engine will be in trouble. Most other engines do not have this small membrane, and once the water is inside, it cannot escape. (Engines are certainly not designed for moisture of any kind inside them).

Does my crankset sometimes get stuck when I push my bike out of the garage?

This is because water has entered the bearing during washing or driving. Water will rust the bearing balls on the bearing raceway. This usually means the beginning of the end for the bearing.

Is it OK if I put some oil on the bearings or in the crank?

No! If you think you need to put oil on the bearings, something is already wrong and needs attention. Besides, these engines are not designed to contain oil inside. This can cause problems with the journal bearings, circuits, coatings and lubricants. Above all, it creates a mixture of grease and oil that goes where nothing should be and smears surfaces that should be clean. Even if you only drip a few drops occasionally, it will build up over time.

Does driving in turbo mode cause additional wear or damage to the engine?

Turbo mode adds a little more power through the drivetrain and so the engine may wear out a few kilometres faster than at some of the lower power levels, but in truth we have not seen any difference in any engine that has worn out or failed because it was used at its higher power levels.

Does tuning or chips cause any damage?

We have not yet seen any damage caused by the use of an engine restriction device.

What can cause engine damage or wear besides water and dust?

Slightly higher wear rates are observed for engines used with slow cadence in high gears, so that the engine revs relatively slowly but tries to add full power. Pedalling at higher cadence (rpm) is definitely better and more efficient for the engine. Pedal knocks and bumps can cause damage, but that’s all! As a rule, engines are very resilient if they are well maintained.

When should I have my engine serviced?

Most e-bike engines are not serviced and will last for thousands of kilometres when dry. Yamaha and Impulse engines are the exception to this rule, as they have a special grease that wears off or dries out, which can cause excessive friction and wear. Yamaha and Impulse do not give a recommended distance for this, but in our experience we would service a Yamaha used off road after 2,500 to 3,500 kilometres, and if used on road, 5,000 to 6,500 kilometres. We would recommend servicing the Impulse engine at 2,500 kilometres at the latest.

Can I get more power from my engine?

At the moment, this cannot be achieved in a straightforward way.

Can I exchange my engine for a newer model?

In some cases it might be possible, but not as easy as it sounds. Motors can vary greatly from one model to another; size, type of driver, size and position of mounting screws, type and position of plug for wire connection, etc. All of this can change, along with compatibility with older batteries and controllers. If you are experiencing these problems, then it is usually cheaper and easier to buy a new bike.

Brose

Does my engine need regular maintenance?

The Brose engine should have the drive belt replaced after 15,000 km. The rest of the engine is not designed to be serviced and should only be repaired if it starts to fail.

The motor works in walk assist mode but not when I pedal?

This is usually caused by a faulty torque sensor and should be sent to us for a replacement.

My shaft is hard to turn back

This is usually the first sign that the engine’s needle roller shaft bearing is starting to deteriorate due to rust or a build-up of dust or grit.

My engine makes popping, crackling or squeaking noises

A pretty sure sign that one of the engine’s two clutch bearings is failing. It is definitely worth investigating as this will result in a complete loss of drive.

My engine keeps running when I stop pedalling

This can happen for one of two reasons:

  1. The motor shaft needle roller bearing is badly worn, degraded or contaminated. This causes the motor shaft and the sprocket carrier (torque sensor) to become one unit or very difficult to turn independently of each other.
  2. The clutch bearing starts to fail and the “clasps” (the little shoes that lock the bearing) start to stick or stick together. Both scenarios allow the motor to continue adding power because it can only see that the motor shaft is still rotating. This can happen up to the cut-off speed.