Bosch sprocket issue

[Sander23]

So I changed my 11 so XT drivetrain to sram ex1 and now my chain touches the motor.

A while ago I had tried 21t kmc sprocket with E-chainguard but I had to much chaindrops on the front sprocket. Then I switched to this sprocket and problem was solved

How can I fix it so the chain won't touch the motor?

 

[Maxb]

Did you change the front chain ring?
If your bike is boost spacing you need the offset chain ring

 

[Sander23]

Yea I did that a half yea ago. But with the 11 speed chain I had no issues

 

[Sander23]

I thought it was the sound off rubbing the chain against the motor but I put a small alluminum ring bestween the motor and the sprocket. Bit the sound is still there.

 

[HumphreytheBear]

Without sounding like a nut , can you put it on backwards , upside down or backwards ... ?
I had the same issue , but my front cog was raised on one side
Offset is probably the best word .
replacement cogs - not Bosch branded are flat .

 

[Sander23]

Without sounding like a nut , can you put it on backwards , upside down or backwards ... ?
I had the same issue , but my front cog was raised on one side
Offset is probably the best word .
replacement cogs - not Bosch branded are flat .

What do you mean? I need to paddle backwards?( If so I can't do that)

 

[HumphreytheBear]

Hahaha , yes , sit on the handlebars !
no , the Bosch rings are offset to counter the boost chain line - I think the haibike don’t run a offset ring .
Although in your message you said you put a spacer ring in ?
Admittedly I ve only ever run the xt durarace chains - I have just bought a kms , so i will have to check it before riding too far
only other q is - are the plastic covers all fitted correctly, , mine filled with mud and was a bit wonky .....

 

[Sander23]

This is the original haibike sprocket that came with the bike.
But that's an 16t and I find it to small. The same sprocket goes 18t I believe. The one above that I have now is a 20t and it's perfect for my usage.
I don't have any plastic covers I believe.

 

[Jamze]

That does sound like the chain hitting the plastic motor cover.

Just looking at those two chainrings (the original that has a guard on both sides compared with the completely flat 20T one) looks like you've moved it >5mm closer, which will be an issue. I think you'll need more than a small spacer.

 

[Sander23]

I installed the original chainring and the sound seems gone after a small test ride.
What options do I have if I want a 20t chainring up front?
The sram ex1 sprocket seems to have up to 18 t but then I have the same problem.
Kmc and connex has only flat chainrings

 

[Sander23]

Miranda Bike Parts
I found this one but has a 3mm offsett. Idk if that will be enough.
Or do I get this https://www.bike-components.de/cach...versal-universal-62269-202487-1515656100.jpeg

Maybe a dumb question but will my chain fit on a 22t sprocket when I made it on a 20t one( biggest sprocket back and front + 2 links +quicklink)

 

[Jamze]

Same issue others have had .

You could measure from the back of the mount plate to the centreline of the chainring teeth on both the original and the 20T, and find a spacer that makes up the difference? Biggest I've seen for Bosch is 2.5mm, and they say only use one ?

 

[Sander23]

I haven't found any spacers for Bosch.
How can I measure the offset?

 

[Jamze]

How can I measure the offset?

I have a digital vernier calliper for stuff like this. Difficult though. You could get a rough idea just doing it by eye with a steel ruler, good enough to get a ballpark figure.

 

[Bones]

I sorted mine with a milk bottle. The new flat basic 14t chainring needed a couple of spacers making.

 

[Sander23]

I contacted Miranda they said the original is a 5mm offset. So the only sprocket they have is a 16 t double bash Wich cost 128€.
They do have a 3mm offset 20 and 22t sprocket. Will that be enough if my sprocket now is witouth offset( at least I think it's without)

 

[Bones]

Just stick a rubber O ring behind the sprocket to get 5mm

 

[Bones]

Edit. My set up allowed for plenty of adjustment before the sprocket did not sit on the splines

 

[Sander23]

Edit. My set up allowed for plenty of adjustment before the sprocket did not sit on the splines

You have any examples of o rings?

 

[Zamzoo]

You have any examples of o rings?

For anyone who ends up here via googling as I did, I've just done the same as Bones. I used two of the Bosch O-Ring For BDU2XX together, stretched on to the splines, to push the Haibike chainring out ~2.5mm. Seems the spacers are hard to come by in the UK now.