Conversion - Installing Bosch Gen4 Speed in Bosch Gen4 CX Frame

ruppia

Active member
Dec 14, 2020
250
183
Italy
Hello to you all,

For weeks I have been reading posts about the difficulty of performing unlocking in Bosch Gen4 engines.

I was wondering if it was theoretically possible to replace the CX with the 45kmH Speed version

This would give a perfect result for me, as long as it can be mounted without problems.

Motors on ebay you can find several, even the CX American version with 32kmh limit

What do you think ? Do you have any idea if it could work without going to the mechanic ?
 

Bones

E*POWAH Elite
Subscriber
Apr 3, 2020
893
1,167
Harrogate
The motor cases ,mounting holes and mechanics are all the same as far as I know.
It's only the electronics that's different.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,548
5,039
Weymouth
The motor cases ,mounting holes and mechanics are all the same as far as I know.
It's only the electronics that's different.
not if the frame was made for the Bosch Smart version of the CX motor.
 

ruppia

Active member
Dec 14, 2020
250
183
Italy
If it's the regular gen 4 just derestrict it.
It's cheaper and it's been flawless on my bike
Derestrict it could be quite complicated for some bike and rim magnet.
Sander, what is your bike ? which brand is your chip ?
 

Sander23

Active member
Aug 28, 2020
740
457
Belgium
I have have a regular bosch gen 4 running on a self made rotor magnet.
Chip bikespeed rs and is from Germany.i have it on 3 motors 2 old gen2 (for 15k km) and 1 gen 4 ( 6.5k km) and it's been flawless, no error and no speed limitation.
 

ruppia

Active member
Dec 14, 2020
250
183
Italy
I was referring to the Bosch smart system and the difficulty in getting a stable and effective unlocking.

With an extra expense you could get very good speed without any error problems, and a spare motor just in case you need it or sell the bike

That's why I wanted to know if the change was possible, especially electronically and mechanically.
I would also like to know if it is necessary to go to bosch for some sort of initial setup
 

Sander23

Active member
Aug 28, 2020
740
457
Belgium
I was referring to the Bosch smart system and the difficulty in getting a stable and effective unlocking.

With an extra expense you could get very good speed without any error problems, and a spare motor just in case you need it or sell the bike

That's why I wanted to know if the change was possible, especially electronically and mechanically.
I would also like to know if it is necessary to go to bosch for some sort of initial setup

They have devices on the smart systemwith all sort of sensors.
The after sales support is also on point, very very fast .

I also don't know if you can just order a speed version. I've read that you have to show/exchange them the old motor
 

fasterjason

Member
Dec 17, 2022
108
59
USA
I was referring to the Bosch smart system and the difficulty in getting a stable and effective unlocking.

That's why I wanted to know if the change was possible, especially electronically and mechanically.
I posted this question last year, but about non-smart gen 4. Everything is the same except PCB, which limits container files that can be installed. I have not used a smart gen 4 line speed. I haven't tried the swap because I still use my commuter.

 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
973
2,322
UK
I was referring to the Bosch smart system and the difficulty in getting a stable and effective unlocking.

With an extra expense you could get very good speed without any error problems, and a spare motor just in case you need it or sell the bike

That's why I wanted to know if the change was possible, especially electronically and mechanically.
I would also like to know if it is necessary to go to bosch for some sort of initial setup
If both motors are "smart" system, they can be swapped but then the bike would have to be connected to Bosch software to let the controller know it now has a new motor and to talk to it. I am not sure whether you will have a problem at this point, if the Bosch software recognises that your bike was not originally fitted with a speed motor. Personally, I don't think it will work. But let me know if you find otherwise.
 

aegidius

Member
Sep 30, 2023
48
28
brisbane
I would imagine that the new motor would work with any Bosch battery, otherwise battery swaps would be too complex - but it may have to be paired with the display (Purion etc). You may be able to get around this by buying a new motor along with its display. (I'm thinking of getting a NZ spec CX for a similar motor swap, and have been wondering about these same questions)
 

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