Shimano XT Cassette, Help Needed!

[som3blok3]

Hi everybody,

I'm slowly changing all the standard chainset on my Boardman Hybrid from Sram to Shimano.... Until today it was easy.

I've done the chainset, now using a 105, 5700 double crank and BB.

Done the front and rear hubs to XT (9 speed of course).

Put a shiny new chain on, HG98.

Today I bought the XT M770 11-34 cassette, fitted it no probs went for a ride and it sounds and feels awful!! It's like some sort of grinding sound but I can also feel it through the pedals.

The chain should work as it's the skinny sort, the rear deralliur (speelcheck needed) is a nine speed, the hub is nine speed and the cassette is nine speed.

What am I missing? Is it because the old Sram cassette was 11-32 and the new is 11-34? Its only an extra tooth on a few of the cogs surely, theres still 9 of them!?

I've tried H + L screws and even the B screw, adjusting all over the place, still no joy. It's a shame because the XT Cassette feels really light and nice.

Anybody else had this issue??

 

[rusky]

I have a feeling that Sram shifters my not be compatible with Shimano mechs.

Also, how old are the cables? I had a similar issue that was traced down to a frayed cable.

 

[som3blok3]

I've had the bike 6 months from new, a few shots of GT down the cables when needed to keep em slick. No problems there.

I do all my bike work with it upside down on a big sheet of cardboard (in the back room of my shop) so I can turn the pedals and look/listen to every part, and I'm sure it's an issue with the chain/sprockets. Just can't get my head round why?!? There was me thinking I've become really 'bike savvy', every days a school day and all that!

If it's the rear mech, will I need to change the Sram X5 shifters aswell??

 

[rusky]

Is the rear mech original?

I had pretty much the same issue, everything seemed OK in the workstand but had a grating noise at the larger end of the casette. The cale had frayed inside the outer. Nothing was obvious until I removed the inner.

 

[RecordAceFromNew]

Sram and Shimano 9 speed cassettes have identical sprocket pitch/spacing and spline, so should be interchangeable.

However if you have increased the max sprocket size from 32T to 34T, assuming you have not changed either the shifter or the rear mech (generally neither of which can be mixed and matched between sram and shimano), then the chain could be too short. Assuming the large chain ring of the chainset remains the same as before, increasing large rear sprocket from 32T to 34T usually means two extra links. However if this is a problem it should only be noticeable when you are on the large chainring and the large sprocket at the same time.

You said "I've tried H + L screws and even the B screw, adjusting all over the place". Have you done it systematically step by step as in here?

 

[som3blok3]

Yeah, original mech. All works ok though. In the last hour of my working day (bit quiet in the ironmongery business post Crimbo!) I swapped cassettes back and forth four times, the Sram P950 was fine and the XT M770 wasn't. Bit odd as sitting side by side on the bench they both look the same?

 

[som3blok3]

Sram and Shimano 9 speed cassettes have identical sprocket pitch/spacing and spline, so should be interchangeable.

However if you have increased the max sprocket size from 32T to 34T, assuming you have not changed either the shifter or the rear mech (generally neither of which can be mixed and matched between sram and shimano), then the chain could be too short. Assuming the large chain ring of the chainset remains the same as before, increasing large rear sprocket from 32T to 34T usually means two extra links. However if this is a problem it should only be noticeable when you are on the large chainring and the large sprocket at the same time.

You said "I've tried H + L screws and even the B screw, adjusting all over the place". Have you done it systematically step by step as in here?

Now that makes sense, didn't think of that! Looking at it earlier it did look like the rear mech was over stretching on the larger sprocket (it looked almost 45 degrees towards the front of the bike, if not more) . As for the front chainring, it never gets a sniff of the smaller ring, never needed.

I kept the 3 links that I took off the new chain so hopefully I can just 'pop' two of them back on?

 

[rusky]

Is it only in the larger cogs you have the problem & is shifting in general OK?

 

[som3blok3]

Shifting works ok but the noise/feeling was from most if not all of the gears.

 

[rusty bearing]

If you've changed the cassette and not the chain there's your problem. Put a new chain on. Simples....

 

[rusky]

If you've changed the cassette and not the chain there's your problem. Put a new chain on. Simples....

Put a shiny new chain on, HG98

 

[TheDoctor]

Not wishing to chuck a spanner in the works, but if you never use the inner ring as it's not needed, why are you going for a wider-ratio cassette?
I'd have gone for a close ratio one, and used the inner ring to give you the lower gears - that's why it's there.
Using big ring - big sprocket is a sure-fire way to get crap shifting and wreck your chain, front mech and chainring very quickly.

 

[RecordAceFromNew]

Now that makes sense, didn't think of that! Looking at it earlier it did look like the rear mech was over stretching on the larger sprocket (it looked almost 45 degrees towards the front of the bike, if not more) . As for the front chainring, it never gets a sniff of the smaller ring, never needed.

I kept the 3 links that I took off the new chain so hopefully I can just 'pop' two of them back on?

Yes, with care please.

Shifting works ok but the noise/feeling was from most if not all of the gears.

This indicates that the problem is not just chain length. Assuming the XT does not move side-to-side on the freehub, if you lay both cassettes on a table are the cogs at exactly the same level? If not indexing will have to be reset. Following the Park Tool guide step by step is likely to help.

 

[som3blok3]

Not wishing to chuck a spanner in the works, but if you never use the inner ring as it's not needed, why are you going for a wider-ratio cassette?
I'd have gone for a close ratio one, and used the inner ring to give you the lower gears - that's why it's there.
Using big ring - big sprocket is a sure-fire way to get crap shifting and wreck your chain, front mech and chainring very quickly.

The works are wide open, waiting for the inevitable spanner, no worries there friend. Tbh I only ever use the highest 5-6 of the rear sprockets, just went for a few extra teeth to help on some of the hills on the daily commute.

 

[som3blok3]

Yes, with care please.




This indicates that the problem is not just chain length. Assuming the XT does not move side-to-side on the freehub, if you lay both cassettes on a table are the cogs at exactly the same level? If not indexing will have to be reset. Following the Park Tool guide step by step is likely to help.

Care will be taken! And I think that laying both cassettes side by side is first on the list tomorrow, I've already got enough to sleep on.

As always, thanks for all the input.