Changing the front sprocket to a 32t on an E8000

[Silver fox]

I have a 2020 Sight VLT C2. The factory options for the front sprocket start at 34T, and I would like to step down to a 32T. Shimano does not offer a 32T for this configuration and I’m wondering why. I can see that a smaller diameter front sprocket may not fit inside the chain retention device as it does have a slot that the chain rides in which may not be low enough to accommodate the smaller sprocket. Also the chain may rub on the rubber device on the rear triangle When in the small sprocket on the cassette. Has anyone made this switch and not had any problems?

 

[Gary]

The E8000 uses a normal 4 bolt 104BCD (bolt patern) on it's spider so any 4 bolt 104bcd ring will fit.
in order to allow the chain device to still offer good retention simply pack the top inner of the guide plastic with a strip of 3M mastic tape (this will also quieten it.
sorry can't help you with anything helpful concerning frame clearances. But if you meant the small rubber piece on the end of the chain guide plastic rotating the devices mounting plate slighty (undo the 4 retaining screws and reposition) but be careful to leave enough clearance for the chainstay when your rear suspension fully compresses.

 

[Silver fox]

Thank you Garry.
My understanding on the piece that positions the chain retention device can only to moved to suit a 34 or 36T.
The chain guide is narrower on the bottom then the top, as the guide does cover the sprocket and the chain, the chain being wider. It seems to me that be using a smaller sprocket, the chain position would be lower and thus rub on the retainer. Also, getting at the piece behind the retainer involves removing the spider, and no one here stocks the required tool, ( for sale). I’ll have to order one on line.

 

[Gary]

No. 34 or 38t

I run a 36t ring with the guide in the 38t position and a strip of Mastic under the top of the inside of the plastic guide to close the upper gap. the same would work fine running a 32t ring with the guide in the 34t position.

Also, getting at the piece behind the retainer involves removing the spider

No it doesn't. simply undo the 3 screws behind the chainring/spider and you can rotatye and reposition the backplate.
you only need a specific tool to remove the spider. Which you don't need to do unless you are removing the backplate completely.
If you are fitting a guide with a 2 bolt backplate you could simply cut through the Shimano backplate. (I've cut a portion of mine to allow quick removal without having to use the spider retaining ring tool)

 

[Silver fox]

Garry, thanks again.
Did you find a Shimano 32T narrow/wide that will fit onto the spider? The local shop here has a knock off brand that didn’t look anything like the Hollowtech.

 

[StuE]

Garry, thanks again.
Did you find a Shimano 32T narrow/wide that will fit onto the spider? The local shop here has a knock off brand that didn’t look anything like the Hollowtech.

I had a 32t Hope ring on mine

 

[Kernow]

It could depend on what your lowest gear is on the rear , the sensors in the shimano motor don’t seem to cope with lower gearing . I can’t remember the numbers now as I don’t have that bike but when I tried a smaller front ring the motor would switch in and out When using the lowest gear , rendering it useless

 

[Gary]

I thought that only happened when the motor was derestricted?
ie. only sending wheel sensor data every second time the magnet passes it.

 

[DSA]

E8000 has no problems with the 32t, using this for 2 years now.

 

[Silver fox]

As I’m still under warranty, and Shimano does not seem to make a 32 in the 8250 Series, I think that I will stay with the 34T for now.
as an aside I have been playing with the “walk” mode and it does leave a lot to be desired. It only seems to want to assist when you are in a high gear, and you need it when you are in the lowest gear!

 

[Kernow]

I thought that only happened when the motor was derestricted?
ie. only sending wheel sensor data every second time the magnet passes it.

Yes your right , it was de restricted and turning off the dongle cured it . I remember now . It was a pain having to choose which to have on

 

[Kernow]

As I’m still under warranty, and Shimano does not seem to make a 32 in the 8250 Series, I think that I will stay with the 34T for now.
as an aside I have been playing with the “walk” mode and it does leave a lot to be desired. It only seems to want to assist when you are in a high gear, and you need it when you are in the lowest gear!

You can change gear in walk mode to get it to run at the right speed , just shift as you normally would ,I think all ebikes are the same . I know what you mean when you need walk mode it’s because you’ve come to a halt in the lowest gears

 

[Silver fox]

Thank you, I will try that. The problem seems to be that there is zero assist from “walk” when I’m in granny on a steep slope, so shifting was not possible ( the cranks have to be moving to shift).

 

[rafaellop]

I run a 36t ring with the guide in the 38t position and a strip of Mastic under the top of the inside of the plastic guide to close the upper gap. the same would work fine running a 32t ring with the guide in the 34t position.

I'm at the moment upgrading my E8000 bike to 32T as shown in the picture below, but I'm not quite sure how to modify the chain guide. Could you please mark it on the photo or post a photo of yours?

 

[Gary]

I don't have an E13 chain guide. I have a shimano one.

 

[Silver fox]

The ethirteen came on mine also. I don’t think that they can be adjusted that far.

 

[rafaellop]

My guide is at the max bottom on the adjustment as possible. I'll try to test the 32T on Monday and I'll let you know how it works on my bike (not derestricted).

 

[bikedrd]

You can change gear in walk mode to get it to run at the right speed , just shift as you normally would ,I think all ebikes are the same . I know what you mean when you need walk mode it’s because you’ve come to a halt in the lowest gears

The cranks will move in walk mode. That's how the motor assists. So you can shift.

You are holding the walk button down, yes?

 

[Silver fox]

I had the opportunity to try walk mode today and it was a non event. While I could hear a sound that sounded like an engagement, there was no help. I was likely in the 3rd smallest sprocket after numerous downshifts. Do you need to continually hold the walk button down to get a response, or only when down shifting?