36t Cassette with Deore LX Mech

[Spiderweb]

So I’ve finally got around to swapping my cassette from a 34t to a 36t on my CX bike. The chain length seems ok but I feel the top jockey wheel is too close to the 36t sprocket, is there anything I can do to make this work?

 

[Blue Hills]

Have you checked the capacity of that mech?
I recently built up a bike with a 9 speed 12-36 cassette on the back.
I thought it would work as the componentry matched my Hewitt. Or I thought it did.
But I couldn't get the XT rear mech to work.
Despite endless tinkering, screwing the B screw right in etc.
Then I discovered that Mr Hewitt had put a 34T big tooth cassette on the back even though the printed specs said he'd put a 36T on.
Changed the mech on my build and all well.

 

[si_c]

Assuming winding in the b-tension screw doesn't work - on the last photo above it looks like it's not all the way so you should be able to adjust it off, you can try two things.

If winding the b-screw in doesn't work then if it's almost working then you try screwing it in from the wrong side - this should give you an extra couple of mm of adjustment.

If that doesn't work then a derailleur hanger extension like a wolftooth road link or a Sunrace Derailleur extender (I use the latter on my MTB to use a 42t cassette) will work well.

 

[Ming the Merciless]

As above try adjusting the b screw to move it away from cassette

 

[Blue Hills]

You can also get longer B screws - I never tried that remedy though - just fitted a different rear mech.

 

[Spiderweb]

Thank you everyone.

The capacity of this mech is, I think, 34t but as with a shorter cage mech (capacity 28t but from experience 30t works fine) I was hoping it would be ok too.

I’ve screwed the B screw right in now and it looks to have given that tiny amount of extra clearance that I needed.

These are actually a second set of wheels with nobblier tyres, I wanted to be able to swap wheels to suit riding conditions rather than faffing about changing tyres. I feel as though occasionally I need an easier gear and already had the new 12-36t cassette in stock so thought I’d give it a try too.

 

[Spiderweb]

You can also get longer B screws - I never tried that remedy though - just fitted a different rear mech.

I didn’t know that, thanks for the info👍

 

[Cycleops]

That’s an MTB mech so should be able to handle 36t. The B screw looks like it’s just about all the way out so screwing it in should fix it.

 

[figbat]

I have the same situation on a frankenbrew drivetrain I have put together. I have a longer B-screw inbound (M4 stainless bolt) and will look to a Wolftooth if that isn’t enough.