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Answered Own service

Gixxer162

New Member
Mar 11, 2019
10
6
Lake district cumbria
Hey I just got my bike in January has the Bosch cx motor and I am going to learn everything I can about this thing to do my own servicing how often should I be doing it ??
 

SquireRides

E*POWAH Elite World Champion
Sep 4, 2018
540
555
UK
Bosch don't give you much (any) information about how to look after a Performance Line CX motor... But these forums can help!

I've used this motor for a year and a half, and had one failure/replacement in that time. Something I didn't want to repeat, so I did a lot of research.

What you need to know is this:

The biggest risk is to the drive-side internal motor bearing. This is what usually fails, and it's also the only thing you can maintain or replace yourself.

The motor seals are not water proof. Their IPX rating is pretty poor: Sealed to light spray and larger-than-sand debris.

DON'T SUBMERSE OR HEAVILY SOAK THE MOTOR - I think my problem was I frequently cycle through a ford!

YOU MUST MAINTAIN THE DRIVE-SIDE SEAL

Take you drive side crank off, the Bosch chain ring (you'll need the Bosch spider tool) and behind that you'll see a black seal.

Take it off carefully, clean behind and pack behind with lots of grease with a good water resistance. Replace seal. Replace cranks etc...

That's all the maintenance you can do.

After that, if the drive side bearing still fails, Bosch now offer a replacement you can do yourself (or your LBS can help). Previously, you had to send the whole motor/bike away to get a replacement (and probably still do if its a warranty fix in the 2-year warranty period).

This is it: New Bosch CX Motor Refresh Kit (EMBN) <3 <3 <3 - EMTB Forums

Hope that helps! If I'd known this before, I'd probably still be on my first CX motor!
 
Last edited:

Gixxer162

New Member
Mar 11, 2019
10
6
Lake district cumbria
Bosch don't give you much (any) information about how to look after a Performance Line CX motor... But these forums can help!

I've used this motor for a year and a half, and had one failure/replacement in that time. Something I didn't want to repeat, so I did a lot of research.

What you need to know is this:

The biggest risk is to the drive-side internal motor bearing. This is what usually fails, and it's also the only thing you can maintain or replace yourself.

The motor seals are not water proof. Their IPX rating is pretty poor: Sealed to light spray and larger-than-sand debris.

DON'T SUBMERSE OR HEAVILY SOAK THE MOTOR - I think my problem was I frequently cycle through a ford!

YOU MUST MAINTAIN THE DRIVE-SIDE SEAL

Take you drive side crank off, the Bosch chain ring (you'll need the Bosch spider tool) and behind that you'll see a black seal.

Take it off carefully, clean behind and pack behind with lots of grease with a good water resistance. Replace seal. Replace cranks etc...

That's all the maintenance you can do.

After that, if the drive side bearing still fails, Bosch now offer a replacement you can do yourself (or your LBS can help). Previously, you had to send the whole motor/bike away to get a replacement (and probably still do if its a warranty fix in the 2-year warranty period).

This is it: New Bosch CX Motor Refresh Kit (EMBN) <3 <3 <3 - EMTB Forums

Hope that helps! If I'd know this before, I'd probably still be on my first CX motor!
That is exactly the info I wanted pal thanks so much ????????
 

SquireRides

E*POWAH Elite World Champion
Sep 4, 2018
540
555
UK
Never used gasket seal, but I assumed it is intended for non-moving parts, such as a... gasket?

Through the drive side seal is the main drive shaft in to the motor, which rotates. Grease is good on rotating parts.
 

Uppy

Well-known member
Mar 8, 2018
94
114
Cambridgeshire
I had the same problem, my motor failed after riding it 318 miles from new,.water got into the motor..bosch where good, replaced the motor under warranty and another 2 years on the motor starts again..
I was told by the service guy you can sort of prevent it by maintaining the drive side..so I brought myself a Bosch spider tool for my cx motor. Extract the crank arm, remove the chain cover with bosch tool..there are different suppliers tools which are cheaper to buy, if you didn't want to buy a bosch one. When this is removed you can remove 'o' ring that sits in front of the chain ring..once removed there is sometimes a spacer behind the chain ring. Take that off, then you see the seal..pop that out. You can reuse these if you don't damaged it..clean it up, clean the bearing, regrease, po seal back in, wipe access grease away. Reassemble, and ride..I do this every 3 months..
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
If this seal service every three months saves the motor, you'd think it would be in Bosch's interests to provide the specialist tools and full instructions with every Bosch motor.

Eventually, someone at Bosch will realise that improving the seal might be a better solution.
 

SquireRides

E*POWAH Elite World Champion
Sep 4, 2018
540
555
UK
If this seal service every three months saves the motor, you'd think it would be in Bosch's interests to provide the specialist tools and full instructions with every Bosch motor.

Eventually, someone at Bosch will realise that improving the seal might be a better solution.

Let's see what the Gen4 motor is like....
 

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