Fuel EXe Rear wheel won't spin freely after upgrade to SRAM GX T-type transmission?

ZillaG

Member
Nov 15, 2022
58
43
Cary, NC USA
I upgraded my stock Fuel 9.7 to an SRAM GX T-type transmission. I upgraded the following and torqued everything to spec.
  • XD driver and end caps
  • Cassette
  • Derailleur
  • Chain
  • Remote

But now my rear wheel will not spin freely. Notice how when I stopped back-pedaling, the rear-wheel stopped. Conversely, when I hold the wheel, the cranks won't spin along with the chain.

NOTE: The bike shifts flawlessly, and the cassette spins freely when the wheel is off the bike!

What can I look for?

 
Last edited:

Stihldog

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Jun 10, 2020
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Coquitlam, BC
The new cassette seems to be crushing into the spokes. Or the free wheel hub is not installed correctly.

Maybe a spacer is required?

Check the routing of your chain, carefully, but it doesn’t seem like that.
 

Stihldog

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Jun 10, 2020
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Coquitlam, BC
Are the jockey wheels turning freely. Is the chain correctly threaded through the transmission (easy to make this mistake). Did an axel cap fall off. Correct speed cassette 10-11-12? Is the axel torqued correctly (usually 10nm).
“B” screw adjustment?
Install the wheel without the chain and check.
It could be one of those ah-ha moments.
 
Last edited:

ZillaG

Member
Nov 15, 2022
58
43
Cary, NC USA
Are the jockey wheels turning freely. Is the chain correctly threaded through the transmission (easy to make this mistake). Did an axel cap fall off. Correct speed cassette 10-11-12? Is the axel torqued correctly (usually 10nm).
“B” screw adjustment?
Install the wheel without the chain and check.
It could be one of those ah-ha moments.
I did everything correctly per manual and videos. There's no B or limit screw adjustment on the T-type. Everything seems to work fine, including the actual shifting, except for this phenomenon.
 

Stihldog

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Jun 10, 2020
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Coquitlam, BC
There may be someone here who has more experience with this than I do with T type transmissions. We’re both missing something. Sry 🤷‍♂️
 

Montana St Alum

Active member
Feb 13, 2023
257
204
Park City Utah
12 speed on XD needs a spacer according to this. I don't know if it applies to your situation, though. I'd guess a new cassette would have come with it, if you needed it.
Time 0:42
 
Last edited:

Paul Mac

E*POWAH Elite World Champion
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Jul 9, 2018
997
1,046
Uk
I think the bontrager wheels are sensitive to how tight you do up the rear axle.
On my old trek rail without the new axs installed, if I torqued up the axle too much it would stop the wheel spinning freely.
 

Koban

Member
Oct 15, 2023
86
134
Germany
On my DT HXC 1501 wheel set with 240 hubs I had something similar. I had same with the XX1 cassette. In my case it was the free hub. Sometimes the cassette is not fitting correctly. Casette was tied. But spacing of the end cap was not correct. And tidying more was not fixing it. It was damaging the thread from the cassette.

When I notice that the cassette is not vitting correctly (spacing end cap). I remove the cassette. Clean the threads from the cassette and hub. Some new grease on it. 9 of the 10 times will do it. ;-)
 

Dave_B

E*POWAH Elite World Champion
Aug 29, 2020
1,467
1,593
Newquay
I upgraded my stock Fuel 9.7 to an SRAM GX T-type transmission. I upgraded the following and torqued everything to spec.
  • XD driver and end caps
  • Cassette
  • Derailleur
  • Chain
  • Remote

But now my rear wheel will not spin freely. Notice how when I stopped back-pedaling, the rear-wheel stopped. Conversely, when I hold the wheel, the cranks won't spin along with the chain.

NOTE: The bike shifts flawlessly, and the cassette spins freely when the wheel is off the bike!

What can I look for?


why don't your cranks spin backwards free of the chain ring?
 

Stihldog

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Jun 10, 2020
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Coquitlam, BC
why don't your cranks spin backwards free of the chain ring?
…and should only engage when rotating fwd?

My motor(and cranks) acts as a free hub when rotating backwards. The chainring doesn’t rotate while peddling backwards.

Have you noticed another problem? 🤔 maybe.
 
Last edited:

Colin46

New Member
Aug 11, 2023
28
9
United Kingdom
Something more serious is wrong as some have rightly said the cranks should rotate backwards without the chainring engaging. I would get your motor checked out, it’s not disengaging on a backpedal
 

Dave_B

E*POWAH Elite World Champion
Aug 29, 2020
1,467
1,593
Newquay
He had the chainring velcro strapped to the crank
Not sure why you would do that? Why create a scenario that does not exist on the actual correct functioning of the bike.

I’d simply take everything off the bike and identify why item on the rear wheel is jamming. It’s either the freehub body or the mech.
 

Stihldog

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Jun 10, 2020
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Coquitlam, BC
If it was me …I would start the re-assembly process from the beginning, again. After each (and every) step of assembly I would check when or how the issue occurs. This may be a matter of “process of elimination” to isolate when and how the cassette stops spinning freely.

This may be difficult for some of us to diagnose when the bike is not infront of us and we have a video and some information to rely on. The OP is making numerous efforts to discover the problem. Providing a video is definitely helpful …but that can’t show everything and that can’t show each and every step (unless it’s a lengthy video).

Thankfully or sadly this will become a learning process for most of us. I’m curious and this has my attention. 🧐
 

Dave_B

E*POWAH Elite World Champion
Aug 29, 2020
1,467
1,593
Newquay
Take the chain off and spin the freehub.
Does it rotate backwards? Yes/ No
If no, is it hitting the frame? Yes / no
If no, take the wheel off, spin the hub.
Does it rotate backwards? Yes/no
If no, the cassette is not on correctly.
If yes, maybe the hub spacer is incorrect, or the axle is way over tightened and the hub spacer is interfering with the cassette in some way.

Etc
Etc

Look at one thing at a time and it should be easy to resolve.
 

JayGoodrich

Member
Aug 11, 2023
38
48
Alpine, Wyoming
It’s hard to diagnose without really seeing the details of the bike.

I will say that my Fuel EX-e does not back-pedal like that. Spinning the crank in reverse with the motor on or off just has the crank spinning not the transmission assembly.

So maybe the problem lies in the motor/front chainring.

Also, there is a tab inside of the transmission derailleur universal hanger area that needs to line up before tightening the derailleur/hanger bolt down. That could be screwing up the spacing.

Hope this helps further trouble shoot.
 

jamtb

Member
Nov 21, 2021
13
5
Grove City, Pennsylvania
There is a very think spacer that goes on the axle and it looks like it is part of the axle. It may be missing or in your XD driver you took off. I just went thru this with a bike and it sounds like it. Its about 3/4 long and very thin and goes inside the XD driver
 

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