Bosch gen 4 removal

[RustyMTB]

Anyone taken their motor out? I need to replace my dropper cable & figure the easiest methofd will be with the motor out of the way. Is it a few bolts & connectors to get it out? I wouldn't need the cranks to come off.

 

[Doomanic]

I've taken the motor out of my Rail for just that purpose. Just remember to unplug all the cables first.

 

[Hamina]

The connectors are all different so it's not possible to connect them in a wrong way. Take a photo though how the wires are sorted out before removing everything.

 

[Dave_h34]

You might be able to get reasonable enough access without taking the rear bolts out, just let the motor pivot out of the way on those loosened bolts. Saves all the plugging unplugging.

 

[RustyMTB]

Cheers lads, looks like I'm on the right track.

 

[Aikone]

You might be able to get reasonable enough access without taking the rear bolts out, just let the motor pivot out of the way on those loosened bolts. Saves all the plugging unplugging.

It’s worth putting a zip tie through the frame hole & motor hole to reduce the stress on the cables and connectors while the motor is hanging down.

 

[RustyMTB]

That went well in the end. Thanks again all.

 

[Akelu]

Are the only cables the ones on the side where the sensor/display etc connect? Is the battery connected via there too?

 

[RustyMTB]

Not sure what the exact question you're asking is but in the picture of my bike above, the cable on the left is for the wheel sensor, the middle one connects the battery & on the right is for the purion display. All connect to the motor.

 

[Don_Singer]

It is hard to find a manual, thread, YouTube video or anything on actually taking the motor out. Forget about finding the bolt torque for putting it back together. I have all six bolts out and the motor moves but it didn't just drop out. How hard should a tug on it, or is there something else still connected. Sorry about my frustration but I've been researching running a new brake cable for weeks. Thanks for your help.

 

[RustyMTB]

There are metal plates on the side of the motor that act as spacers and provide thread holes for some of the bolts. They will be holding the motor in situ by friction. Just wiggle it out with as little force as you can get away with & it will dislodge. As for refitting, if it's an aluminum frame, just buzz the bolts up to feel with some blue threadlock or check with the manufacturer for torque settings if you don't trust yourself. If your frame is carbon, then I'd definitely seek out torque values.

Removal tip, turn the bike upside down & lift the motor out rather than dropping it if you're concerned about damaging cables.

 

[Don_Singer]

There are metal plates on the side of the motor that act as spacers and provide thread holes for some of the bolts. They will be holding the motor in situ by friction. Just wiggle it out with as little force as you can get away with & it will dislodge. As for refitting, if it's an aluminum frame, just buzz the bolts up to feel with some blue threadlock or check with the manufacturer for torque settings if you don't trust yourself. If your frame is carbon, then I'd definitely seek out torque values.

Removal tip, turn the bike upside down & lift the motor out rather than dropping it if you're concerned about damaging cables.

Thanks for the info, it turns out there was a small rock behind the chain guide that was causing the friction and the grinding sound that didn't sound good. After that the motor more or less dropped right out. Nice that Trek routed the wires around the back of the motor with a nice service loop.

Does anyone know the torque for the six motor bolts? I know a bunch of people have a problems with creaking and would think the spec is posted everywhere but I'll be darned if I can find it.


Thanks again,

 

[Akelu]

Does anyone know the torque for the six motor bolts? I know a bunch of people have a problems with creaking and would think the spec is posted everywhere but I'll be darned if I can find it.


Thanks again,

Page 244, make sure your looking under the right motor section for your model.

BoschAE_HB2020_UK

Read BoschAE_HB2020_UK by Bosch eBike Systems on Issuu and browse thousands of other publications on our platform. Start here!

issuu.com

 

[TR5_20]

Does anyone know the torque for the six motor bolts? I know a bunch of people have a problems with creaking and would think the spec is posted everywhere but I'll be darned if I can find it.

For the 2020 Rail Alloy it is 20Nm.
Taken from this manual.

 

[Don_Singer]

Page 244, make sure your looking under the right motor section for your model.

BoschAE_HB2020_UK

Read BoschAE_HB2020_UK by Bosch eBike Systems on Issuu and browse thousands of other publications on our platform. Start here!

issuu.com

Thank you, thank you, THANK YOU! 20nm. say it again 20NM!

Never in the history of the internet have I experienced a number so hard to find. It's like Bosch hacks every post and deletes it.

Page 227 also has the diagram for the BDU450CX....or course the Bosch website directs me to the manual for BDU480 CX for 2021, but I assume the motor mount torque would be the same for the same motor series..

 

[Hamina]

Just found out something today:

I was wondering why Bosch sells T40 1/4 torx with a 8 euros price tag here locally. Well one reason could be that Bosch CX GEN 4 T40 bolts are torx PLUS and not ordinary torx.

There's a small difference:

 

[Spiff]

It is still not fully clear for me: When you remove a Motor Bosch 4Gen from bike frame, you have too remove Motor + Mounting brackets from frame or you have to remove the motor from Mounting brackets still attached to the frame?:

• If you remove Motor + Mounting brackets from frame, you take out bolts that attach the Motor Mounting brackets to frame, so you get a motor with the Mounting brackets attached to it . For this you have to follow bike manufacturer instructions for the type of bolts and torque. I guess this is the right answer because these bolts are the ones accesible
• If you remove the motor from Mounting brackets which are still attached to the frame, then you take out the bolts that attach the motor to the Mounting brackets, so you get a motor without Mounting brackets and to do this you have to follow intructions from Bosch and you use a Torx 40 PLUS and a Torque of 20Nm. These bolts are hidden inside the frame, so it is not possible to remove them.

 

[Stihldog]

I’m not exactly sure what the ’interface plates’ are? I guess I call those motor mount brackets. Those generally don’t need to be removed since they attach directly to the motor with smaller security type bolts (sometimes), 4 bolts for each bracket.

There are 6 larger motor mount bolts that require a #40 Torx Plus to remove and/or tighten to 20nm.

Flip the bike upside down. Remove the skid plate. Take a picture for wiring reference. Remove the plugged wires from the motor. The larger plug (power) usually has a clip which needs to be pressed …be careful.
Remove all 6 of the larger motor mount bolts. Carefully lift the motor out. This may take a bit of wiggling …use the crank(s) to help.

The casing is only magnesium so don’t drop it .

 

[Spiff]

Ok, thank you. When I said "Interface plates" I meant "Mounting brackets"

 

[Stihldog]

After dropping the motor, on several Bosch CX type bikes, I got tired of fiddle-f**king with the dropper cable on my bike. I switched to the AXS reverb dropper. (Was 150mm cable, installed 170mm AXS).

Dealt with the rats-nest in the motor area also.

 

[Spiff]

I read in the Bosch manual and here that the motor bolts are M8x16 Torx40 Plus, but this manual is valid for the motor BDU 450 Performance Line CX 2020-2021.

But my motor is BDU3740 Performance Line CX Smart System 2023, I bough a Torx 40 Plus and tried it but it does not fit in the bolt head, then I tried a Torx30 (without removing the bolt) and it fits, but I am not sure if it should be a Torx30 Plus. Does anybody know which one is required

 

[ralfturfsmurf]

I read in the Bosch manual and here that the motor bolts are M8x16 Torx40 Plus, but this manual is valid for the motor BDU 450 Performance Line CX 2020-2021.

But my motor is BDU3740 Performance Line CX Smart System 2023, I bough a Torx 40 Plus and tried it but it does not fit in the bolt head, then I tried a Torx30 (without removing the bolt) and it fits, but I am not sure if it should be a Torx30 Plus. Does anybody know which one is required

the 6 bolts that holds the motor to the frame?
Torx plus 40, also called 40IP