Second hand cargo bike with bosch motor, 5000miles

[JDO]

Hello,
I am looking to buy a cargo bike with a performance line bosch CX motor. It has done 5000 miles in just two years. I am assuming the battery will need replacing at some point, which is straight forward. But I am unsure about the motor. Do Bosch motors wear out after a certain mileage? Can it be replaced?

Thanks,

Jane

 

[Benjahmin]

I don't have direct experience with this motor, however there have been a lot of posts on here about bosch motors and bearing issues.
The main issue is that, whatever goes wrong, there are no user serviceable parts in these motors. Bosch policy is that a dealer will remove the motor and return it to Germany for replacement. They will only supply a new motor on receipt of the old and the cost is high. Generally, it seems, only the dealer who sold you the bike will accept it to work on.
There is a forum member called, 'Performance line bearings' who seems to be able to repair some issues.
Also only Bosch batteries can be used with this system and they are 2-3 times more expensive than general market.
Tread carefully with your hard earned.

 

[vfr400]

I would bet that it's already had a replacement motor. Assuming that it's a few years old nd not the latest version, the weak point is the main bearing where the crank spindle exits on the right side behind the small chainwheel. That arrangement is not sufficiently waterproof, so muddy grime gets in and destroys the bearing, which makes a bigger gap to let water come flooding in. It would probably last a long time if never used in the wet or in winter.

There's an after market seal for that shift, which gives it a better chance of survival. Ask the owner if it's already had a new motor and whether the seal is fitted.

You can test the bearing if you remove the chain and turn the crank. Any noise or grindy feeling is a terminal case.

 

[Nealh]

This will be more of an issue as time goes by lots of folks are wise to the shady mid drive close systems and sell their bikes when the warranty nears or passes as they then can become an expensive ornament. The back up and service from brand dealers is expensive, as has been mentioned PLB in Surrey can repair motors mechanically but not often electrically. These brands in the industry need to make repairs more accessible and reasonable instead of treating them as scrap or landfill commodities.

Take Bosh for instance you would expect our wash machine or dry to be expendable after only 2 years.

Take the case of GeorgeHenry's Yamaha battery with broken discharge connector after 8k miles the dealer told him nothing doing can't repair buy a new battery at £800, George and a mate repaired it for about £2 and has since done another 5 or 6k miles. He was also fortunate with getting the motor replaced at or just after the 2 yr warranty ran out for free.

One reason why I would never buy one of these types of closed system bikes.

 

[Ballynoes]

I have a cube ebike with the Bosch CX motor, has done 1000's of miles in 4 years, and never missed a beat. I think a lot depends on the way the bike is treated. I have seen posts on here where people treat their ebikes exactly the same as an analogue bike, ploughing through mud and water, and look where the motor is placed. Ebike motors ARE NOT waterproof, read the manual, at best they are splash proof. If you charge through mud, water and sand, you will f*** the motor and it's bearings, it's no secret, but all ebike motors are the same. They are also in the firing line of everything which comes off the front wheel. It common sense. There is a guy on here can rebuild your Bosch motor for a fraction of the cost, but batteries are pretty much tied down to Bosch. Some have tried to replace the cells, but most manufacturers have that sewn up as well, with clever software. It's like buying a car, you don't know how the previous owner has driven it...boy racer or miss Daisy, if you have to replace the battery and motor, what's the point in buying second hand. A lot can be gained from the general condition of the bike and asking questions. Does it look well maintained, look closely. Or does it looks "cleaned up" for a quick sale. If in doubt walk away don't be too keen to buy.

 

[soundwave]

you can recell the frame batts if the bms is working but it is still going to be about 400 quid but this is not a option with the power tube batts that fit in to the frame.

plb get a lot of motors with water damage to the controller and thus shorted them out and this can not be fixed or replaced.

 

[Nealh]

As vfr has said many times they make for an unusual garden ornament.