Need help deciding on a reliable motor.

[Bearing Man]

Thanks for all your feedback @Bearing Man. Much appreciated!

What is your experience with the Bosch CX Gen 4 (BDU4xx, non-Smart) in terms of serviceability? Are we also looking at a high repairability percentage similar to Gen 2 motors?

The reason I bring this up is that a few eMTB manufacturers are still selling bike models with Bosch Gen 4 units (non smart) in their 2023 lines. This may be of interest to anyone looking for a Bosch powered bike that don't want to jump on the Smart-system bandwagon.

We thought the Gen 4 was going to be a fantastic motor, but now they are out of warranty we are being swamped with them! There is a few difficult technical issue to get over with calibration etc. But because Bosch put the PCB at the bottom of the motor, any significant amount of water will kill it dead! GAME OVER!

 

[RJUK]

We thought the Gen 4 was going to be a fantastic motor, but now they are out of warranty we are being swamped with them! There is a few difficult technical issue to get over with calibration etc. But because Bosch put the PCB at the bottom of the motor, any significant amount of water will kill it dead! GAME OVER!

Is there anything that can be done to protect it? Weird how they can wash the electronics of a smartphone with a Scotchguard type stuff, but not the electronics of an off road bike!

Also, the ones you're being swamped with, what are the main issues and are you able to repair most of them?

 

[Ark]

Is there anything that can be done to protect it? Weird how they can wash the electronics of a smartphone with a Scotchguard type stuff, but not the electronics of an off road bike!

Also, the ones you're being swamped with, what are the main issues and are you able to repair most of them?

People in the remote control hobby world use it to water proof RC car electronics, or plastidip but you can hardly go spraying plastidip on a pcb inside a motor I'd imagine

 

[RiderOnTheStorm]

But because Bosch put the PCB at the bottom of the motor, any significant amount of water will kill it dead! GAME OVER!

That's good to know, thanks! I'll make sure to keep my gen 4 motor on the dry side.

By "significant amount of water", do you mean the motor would have to be completely submerged in water, or just getting wet for example when riding during heavy rain?

Any tips or recommendations to minimize water ingress in Bosch gen 4 motors?

 

[op2097]

I'm hoping to get some life out of my Yamaha pwx3 on my haibike.

Had a giant with a pwx2 and it had terrible problems with failing smart gateways, controllers and eventually water in the motor.

I'm under the impression that the waterproofing via the crank bearings is still rubbish on the pwx3 but not being a giant version it should have off the shelf PCBs available for when it does go wrong?

 

[RiderOnTheStorm]

@Bearing Man Thinking about ways I could protect my Bosch CX gen 4 motor from dust/water, would you recommend installing the Bosch bearing protection rings to cover the bearing points L1 and L3 of the drive unit? The kit part # is 1.270.020 160. Would it be worth it?

 

[Bearing Man]

Is there anything that can be done to protect it? Weird how they can wash the electronics of a smartphone with a Scotchguard type stuff, but not the electronics of an off road bike!

Also, the ones you're being swamped with, what are the main issues and are you able to repair most of them?

You can remove and coat the board, but the big problem with the Gen 4 is that Bosch have used the motor body as a large heat sink, this puts the electronics close enough to the motor casing to sort out when a drop of water gets to this area (see image below). Unfortunately, once a little water enters this motor, it condensates and usually ends up all over everything. See a typical scene below.

 

[yorkshire89]

@Bearing Man Do you think this water is always getting in through the crank seals? Have you seen any evidence of water getting in through the casing gaskets or anywhere else?

 

[Bearing Man]

That's good to know, thanks! I'll make sure to keep my gen 4 motor on the dry side.

By "significant amount of water", do you mean the motor would have to be completely submerged in water, or just getting wet for example when riding during heavy rain?

Any tips or recommendations to minimize water ingress in Bosch gen 4 motors?

Just one drip in the wrong place will do the job if you're unlucky, but that's the same with most motors.

People in the remote control hobby world use it to water proof RC car electronics, or plastidip but you can hardly go spraying plastidip on a pcb inside a motor I'd imagine

Yamaha, for example, are one of the few who do put a liberal protection coating on their PCB's but it does not really help. Yamaha's PCB's are also at the bottom of the motor, so water seeps through the multi layers of the board and shorts all the tracking out.

 

[Bearing Man]

I'm hoping to get some life out of my Yamaha pwx3 on my haibike.

Had a giant with a pwx2 and it had terrible problems with failing smart gateways, controllers and eventually water in the motor.

I'm under the impression that the waterproofing via the crank bearings is still rubbish on the pwx3 but not being a giant version it should have off the shelf PCBs available for when it does go wrong?

We have not yet played with a PW-X3 so can't comment on the sealing and parts may not be available for this motor as Yamaha are trying to do the same as the other manufacturers with regards withholding the information required to source the parts and not releasing the latest parts.

 

[Bearing Man]

@Bearing Man Thinking about ways I could protect my Bosch CX gen 4 motor from dust/water, would you recommend installing the Bosch bearing protection rings to cover the bearing points L1 and L3 of the drive unit? The kit part # is 1.270.020 160. Would it be worth it?

Your motor should already have these bearing shields fitted and they should be changed from time to time. I would definitely fit a new set going into winter and using the Bosch "tacky" grease, re pack them every 2 to 3 months depending on terrain, cleaning habits and riding conditions.

 

[Bearing Man]

@Bearing Man Do you think this water is always getting in through the crank seals? Have you seen any evidence of water getting in through the casing gaskets or anywhere else?

99% of all water ingress on all motors is through the bearings, not the gaskets or wiring seals etc. Brose have some issues on their earlier motors with water entering by capillary action along the wiring, but this is mostly cured now.

 

[RJUK]

Your motor should already have these bearing shields fitted and they should be changed from time to time. I would definitely fit a new set going into winter and using the Bosch "tacky" grease, re pack them every 2 to 3 months depending on terrain, cleaning habits and riding conditions.

Would Lucas Red n Tacky work? I have a tube of this at home.

It's a thick red marine grease. And can you buy the stuff to coat the PCB yourself? (And is it worth it?)

 

[Bearing Man]

Would Lucas Red n Tacky work? I have a tube of this at home.

It's a thick red marine grease. And can you buy the stuff to coat the PCB yourself? (And is it worth it?)

It depends on what it's made from? Most marine greases are aluminium based and when they come into contact with lithium based bearing grease, it turns it back to oil. This is why many boat trailer wheel bearings fail because people just pump a load of marine grease on top and their normal grease and all the normal grease just runs away from the bearing!

 

[Hattori-Hanzo]

What about hylomar blue gasket and sealing compound, have you had any experience with this?
I've used it on motorcycle engines with good results, it may prove useful for E motors also

 

[Bearing Man]

What about hylomar blue gasket and sealing compound, have you had any experience with this?
I've used it on motorcycle engines with good results, it may prove useful for E motors also

Half the motors have a re-usable silicon sealing bead. The others usually use an RTV silicone sealant. But as I said earlier, no motor will let water in through the gasket faces, it is always through the bearings.

 

[RJUK]

It depends on what it's made from? Most marine greases are aluminium based and when they come into contact with lithium based bearing grease, it turns it back to oil. This is why many boat trailer wheel bearings fail because people just pump a load of marine grease on top and their normal grease and all the normal grease just runs away from the bearing!

So this is the best stuff to use?

Bosch Gen 2, 3 & 4 bearing seal "tacky" grease

Bosch Gen bearing seal Grease for any externally fitted seal or bearing cover. This is an excellent product to greatly increase the life and water integrity

www.ebikemotorcentre.com

 

[Bearing Man]

So this is the best stuff to use?

Bosch Gen 2, 3 & 4 bearing seal "tacky" grease

Bosch Gen bearing seal Grease for any externally fitted seal or bearing cover. This is an excellent product to greatly increase the life and water integrity

www.ebikemotorcentre.com

It's probably not the best stuff in the world! But it's known to work without problems and it's what Bosch recommend.

 

[RJUK]

It's probably not the best stuff in the world! But it's known to work without problems and it's what Bosch recommend.

Thanks.

Here's the description of the red n Tacky... Reckon it'll work?

Lucas Red "N" Tacky Grease is a smooth, tacky, red lithium complex grease fortified with rust and oxidation inhibitors. It has good water resistance and washout properties. It has excellent mechanical stability and storage life. It is able to withstand heavy loads for extended periods of time. It can be used in many agricultural, automotive and industrial applications. Lucas Red "N" Tacky Grease is fortified with a high degree of extreme pressure additives that give it a TRUE Timken load much higher than other greases of this type. Its especially good for sliding surfaces and open gears.

 

[Bearing Man]

Although I know a lot about grease, I would not consider myself an expert so can't really comment on this choice.

 

[Bad Mechanic]

If you want durability, then you want Rocky Mountain's Dyname 4.

It uses a standard bottom bracket, which can easily be serviced to replaced. The motor's cog sits higher in the frame and is protected by a cover with does a good job of keeping water and dirt out. The cog is driven by the motor via a chain in a sealed case, so even if the cog's seals fail, the motor's seals are still protected. The cog, bearings, and chain are all replaceable and user serviceable.

The only knock is it requires the use a mid/high pivot for the suspension. However, as I like how a mid/high pivot rides, I'm quite happy with that arrangement.

 

[Bearing Man]

If you want durability, then you want Rocky Mountain's Dyname 4.

It uses a standard bottom bracket, which can easily be serviced to replaced. The motor's cog sits higher in the frame and is protected by a cover with does a good job of keeping water and dirt out. The cog is driven by the motor via a chain in a sealed case, so even if the cog's seals fail, the motor's seals are still protected. The cog, bearings, and chain are all replaceable and user serviceable.

The only knock is it requires the use a mid/high pivot for the suspension. However, as I like how a mid/high pivot rides, I'm quite happy with that arrangement.

I have to agree the Rocky Mountain is a powerful and user serviceable motor, but it too is not sealed. They rely on just the bearing seals as most other motors do.

 

[Bad Mechanic]

I have to agree the Rocky Mountain is a powerful and user serviceable motor, but it too is not sealed. They rely on just the bearing seals as most other motors do.

-ish. The motor bearings sit inside a sealed space which houses the drive chain connecting the motor to the drive cog. So an contamination would need to make it's way through the drive cog's axle bearings, and then through the motor's bearings.

 

[Bearing Man]

The motor bearings sit inside a sealed space

Ish.. We do find that the water comes through the bearing into the motor housing, as it does on the Brose etc. Sadly there's not one seal on the Rocky Mountain, but I do agree with what you're saying. The drive chain area is pretty well shielded, but the bottom bracket bearings are pretty vulnerable but easy to change, as is the chainring clutch bearing, but when water gets into the output shaft bearing, you're in trouble. Personally, I like this motor, it's built like an American V8

 

[Bad Mechanic]

Ish.. We do find that the water comes through the bearing into the motor housing, as it does on the Brose etc. Sadly there's not one seal on the Rocky Mountain, but I do agree with what you're saying. The drive chain area is pretty well shielded, but the bottom bracket bearings are pretty vulnerable but easy to change, as is the chainring clutch bearing, but when water gets into the output shaft bearing, you're in trouble. Personally, I like this motor, it's built like an American V8

View attachment 116940

Your diagram looks like the Dyname 3.0. On the Dyname 4.0 I don't see an exposed motor bearing. Or are you saying the drive chain cover itself doesn't seal against the motor casing?

 

[Bearing Man]

Your diagram looks like the Dyname 3.0. On the Dyname 4.0 I don't see an exposed motor bearing. Or are you saying the drive chain cover itself doesn't seal against the motor casing?

This diagram is from the Instinct Powerplay Carbon. The bearings fit the same as most ebike motors, where the bearing fits into the machining space for it in the motor housing. Although this protects the the bearing seal to a degree, it does not stop the water traveling along the impute or output shaft and it can then get through the bearing seal and that's then the beginning of the end. Unfortunately, if the bearing is behind the motor case, it is not protected unless there is a seal in front of it (just like any car or motorbike engine). One thing you don't see in that diagram or the BOM list of parts is a single seal on this motor.
Once again, I will agree that the motor drive train and bearings seated behind that plastic cover generally do ok... Well except the clutch bearing crack, but they are generally well shielded so the bottom bracket bearing failure is not an issue for the motor. As I said, these are a pretty good robust (heavy) motor, but they are not sealed.

 

[rzr]

My Levo gen3 motor died (stripped belt) after 10-11 months (3500km, mostly up an down )
however someone said that probably it was from the first batch? and it should be more reliable.

 

[HugoStiglitz]

Botsch make crappy power tools. Shimano make fishing reels. Brose do auto power steering motors. Yamaha has been powering 2 wheels for a long time, my 2018 giant has 15000 kilometers on it no issues. Including dunking it.

Haha, I know a LOT of people that would categorically refute this claim about Bosch and anything they make. They are known throughout the world as making some of the best products. No idea what you're talking about. And just because a company is "known" for a certain thing, doesn't mean they don't and can't make another type of product and make it well. That's silly thinking

 

[RJUK]

Haha, I know a LOT of people that would categorically refute this claim about Bosch and anything they make. They are known throughout the world as making some of the best products. No idea what you're talking about. And just because a company is "known" for a certain thing, doesn't mean they don't and can't make another type of product and make it well. That's silly thinking

Yeah Bosch make a ton of items with motors - washing machines, tumble driers, robot mowers, etc. Admittedly they come across a wide range of price points so the quality will vary.

TBH, for me the reliability is important, but I think the bit that really bugs me and is possibly even more important is the serviceability. The current thought process on that seems to be "when the motor breaks after only a few hundred or thousand miles, just take the whole bike and throw it away, then spend another £5k+ on a new one.... Which will also break in short order and need to be thrown away."

It's obsurd. I'm surprised there's not a consumer law mandating that these things MUST be serviceable with relative ease. I know the EU are looking at creating a "right to repair" law, but it can't come soon enough. I just hope it's sufficiently strict and that charging a customer £600+ for a brand new motor doesn't cut it. It wouldn't take them much to allow us to service the bearings or the gears and replace the electronics.

In an ideal world, motors would all be made to an ISO fitment, so if you didn't like the Shimano motor on your bike, you could sell it and swap in a Bosch... For example.

Then at least you could choose your favourite bike and run it from your favourite motor, or swap out a knackered motor and upgrade to the latest model.

Would be far more consumer friendly and promote greater competition between manufacturers. They'd soon be clambering over each other to make the most reliable, most serviceable motor.

 

[irie]

...
I think that maybe the best and most important question to ask would be... Is this motor repairable!? Then at least when your motor is out of warranty, you can just get it fixed like any other part on your bike.

This ^^^

And the parts to do so must be freely available.