Unanswered Cassette sprockets loose

[Oldebiker]

After a short ride (60 miles) the individual sprockets are loose and move independently of each other and the main body of the cassettes with the lower gears. This has happened on a couple of occasions. Any ideas? I have tightened the lock ring to the correct torque value (40NM). The cassette is a Shimano Deore CS-M5100, 11-51T on a Cube Kathmandu Hybrid Pro 625.

thanks.

 

[salko]

Missing spacer behind the cassette maybe?

 

[steve_sordy]

I had that on a Shimano cassette (can't be sure but probably XT, at least an SLX). The rivets holding one of the clusters together had failed. It wasn't obvious until I removed the cassette. I had bought the cassette from Chain Reaction Cycles and they backed a two-year warranty for all Shimano kit. E-mailed them and sent a few pics, warranty claim accepted by return.

 

[Oldebiker]

Missing spacer behind the cassette maybe?

Thanks for the thought. The documentation doesn’t show a spacer behind the cassette. All the other spacers are in their correct locations.
thanks

 

[Oldebiker]

I had that on a Shimano cassette (can't be sure but probably XT, at least an SLX). The rivets holding one of the clusters together had failed. It wasn't obvious until I removed the cassette. I had bought the cassette from Chain Reaction Cycles and they backed a two-year warranty for all Shimano kit. E-mailed them and sent a few pics, warranty claim accepted by return.

Thanks for the thought. I will take it apart… again and inspect closely.

 

[Bones]

I had an SLX cassette go tits up last week. The large gears are riveted to the main body and they came loose. It wasn't my bike so no idea about warranty but only 2 months old.

 

[Rod B.]

Here's a YouTube video showing the Deore CS-M5100 with the loose cog issue you are describing. Your cassette may still be under warranty.

 

[Oldebiker]

Here's a YouTube video showing the Deore CS-M5100 with the loose cog issue you are describing. Your cassette may still be under warranty.



View attachment 92104

Thanks for this. I will investigate further.

 

[Oldebiker]

Have checked everything… again and all seems to be in order. None of the issues with the cassette mentioned in the replies seems to apply.
thanks all the same to those who replied.

 

[All4Fun]

Sounds to me as if the cassette isn't being clamped enough by the lock ring, missing lock ring washer?
Is the lock ring resting/ tightened against the "bottom" of the body because of too many threads?

What is the distance from the body flange to the tightened lock ring without the cassette and what is the wide of the cassette, if the cassette is smaller than there needs to be an extra washer or so to made it bigger, extra lock ring washer?

 

[Oldebiker]

Sounds to me as if the cassette isn't being clamped enough by the lock ring, missing lock ring washer?
Is the lock ring resting/ tightened against the "bottom" of the body because of too many threads?

What is the distance from the body flange to the tightened lock ring without the cassette and what is the wide of the cassette, if the cassette is smaller than there needs to be an extra washer or so to made it bigger, extra lock ring washer?

Thanks for this. No washer is specified as required in the manuals. The lock ring looks to be hard up against the cassette.

 

[All4Fun]

Thanks for this. No washer is specified as required in the manuals. The lock ring looks to be hard up against the cassette.

Yes, there is one, no:19.

si.shimano.com

 

[RustyMTB]

On that cassette the top 6 sprockets are separate from the rest & install onto the freehub body individually with spacers as noted above. It is perfectly possible for the lockring to be nipped up tight & still have loose sprockets if they have been installed onto the cassette body incorrectly.

Each sprocket fits onto the one behind it very precisely in one location only which you can feel by hand when installing. If you get it right, the sprocket will click into place on the spline with even spacing relative to the previous sprocket around its circumference.

You can check whether this is the issue by rotating the wheel & observing whether or not the high 6 gears look wonky as they rotate. If so, undo the lock ring, reinstall the sprockets carefuilly & ride off into the sunset. Outside of a brokn rivet or similar, it's almost certainly an assembly error by whoever hammered the thing together.

 

[irie]

IIRC the sprockets have tiny alignment marks on them which must be correctly lined up.

 

[RickBullotta]

After a short ride (60 miles) the individual sprockets are loose and move independently of each other and the main body of the cassettes with the lower gears. This has happened on a couple of occasions. Any ideas? I have tightened the lock ring to the correct torque value (40NM). The cassette is a Shimano Deore CS-M5100, 11-51T on a Cube Kathmandu Hybrid Pro 625.

thanks.

Another possibility is an alloy freehub body that has gotten damaged/scored. Remove the cassette and inspect the freehub body.

 

[Oldebiker]

On that cassette the top 6 sprockets are separate from the rest & install onto the freehub body individually with spacers as noted above. It is perfectly possible for the lockring to be nipped up tight & still have loose sprockets if they have been installed onto the cassette body incorrectly.

Each sprocket fits onto the one behind it very precisely in one location only which you can feel by hand when installing. If you get it right, the sprocket will click into place on the spline with even spacing relative to the previous sprocket around its circumference.

You can check whether this is the issue by rotating the wheel & observing whether or not the high 6 gears look wonky as they rotate. If so, undo the lock ring, reinstall the sprockets carefuilly & ride off into the sunset. Outside of a brokn rivet or similar, it's almost certainly an assembly error by whoever hammered the thing together.

Thanks for the thought. The individual sprockets all have one larger gap that corresponds to a single larger ridge in the free hub so they only fit in one place. The spacers are not similarly keyed so they fit anywhere.
All are fitted correctly.

 

[Oldebiker]

Another possibility is an alloy freehub body that has gotten damaged/scored. Remove the cassette and inspect the freehub body.

Thanks for the thought. It is a new freehub body and is unmanaged.

 

[RustyMTB]

Thanks for the thought. The individual sprockets all have one larger gap that corresponds to a single larger ridge in the free hub so they only fit in one place. The spacers are not similarly keyed so they fit anywhere.
All are fitted correctly.

We may be at a misunderstanding. The sprockets do indeed have a gap on the spline designed to ensure correct fitment but it is still not that simple. This video is a good explanation of what can go wrong.

 

[RickBullotta]

Thanks for the thought. It is a new freehub body and is unmanaged.

They all start new. ;-)

It only takes one ride on a loose lockring to damage one.

Hope you figure it out!

 

[All4Fun]

Yes, there is one, no:19.

si.shimano.com

Little update: i have a brand new CS-M5100 11-51 on spare here for a new bike.
Thought i have a look at it, guess what, no spacer, question now, is this a production failure or isn't the PDF right..
Found a used spacer from a CS-6500 and have added this one, spacer is only 0.1mm thick, so it forms to the little teeth of the lock ring.

 

[Oldebiker]

We may be at a misunderstanding. The sprockets do indeed have a gap on the spline designed to ensure correct fitment but it is still not that simple. This video is a good explanation of what can go wrong.

Hi. Just noticed this as I am not a regular visitor/watcher. The spacers on my cassette (CS-M5100 11 speed 11-51t) are all the same; there is no difference in thickness nor spline tooth spacing so they are all interchangeable. The serial number on Shimano’s website is the same for all three of them (item 15) as shown in the diagram below:

The point made in the video about careful locating of sprockets 9,10 and 11 is however valid. I had a couple of times when they did not locate correctly too.
thanks

 

[Brobbo1989]

hey man
ive had this on 3 different occasions on the same deore 5100, the first two I just re torqued to 40nm, the third occasion I removed the cassette completely, degreased, removed every bit of debris, cleaned the free hub and made sure everything was clean and re assembled and torqued, im 200 miles in and still solid.
whether its luck I have no idea but I had the same individual loose sprockets, when tightened to 40nm none of my sprockets move now

hope this helps

 

[Oldebiker]

hey man
ive had this on 3 different occasions on the same deore 5100, the first two I just re torqued to 40nm, the third occasion I removed the cassette completely, degreased, removed every bit of debris, cleaned the free hub and made sure everything was clean and re assembled and torqued, im 200 miles in and still solid.
whether its luck I have no idea but I had the same individual loose sprockets, when tightened to 40nm none of my sprockets move now

hope this helps

Thanks for this. I did exactly the same removal, de-grease, clean re-torque to 40nm as you… several times! After the last time, even though it seemed OK, I just re-torqued without disassembly and now it still seems OK.

none of the ideas/suggestions on here actually identified the root cause so I am none the wiser. Just riding now!

 

[Brobbo1989]

Thanks for this. I did exactly the same removal, de-grease, clean re-torque to 42nm as you… several times! After the last time, even though it seemed OK, I just re-torqued without disassembly and now it seems OK.

none of the ideas/suggestions on here actually identified to root cause

Have you got in touch with Shimano?

 

[Oldebiker]

Have you got in touch with Shimano?

No. Can’t be bothered now that it is behaving!

 

[Oldebiker]

Yes, there is one, no:19.

si.shimano.com

Hi. Thanks for taking the time to reply and I apologise for not replying earlier. There is no lock ring washer specified in the Shimano documentation for my specific cassette. There is no item 19 on the list. See diagram below:

 

[Mikerb]

I am not sure what Shimano rear hub you have and therefore what the freehub arrangement is but it seems to me, given how you appear to have resolved it, that your problem was not with the cassette but rather with the freehub......specifically whether is was fully fixed onto the hub ( it either screws directly into the hub body or is secured to the hub body by an internal bolt ( depending on the specific hub).

 

[Gyre]

FWIW, you might need one of these thin plastic spacers if the issue comes back. They were hard to find when I needed one but helpful.

https://www.mtbr.com/threads/12-speed-xtr-cassette-spacer.1094355/

Edit: Correction - looks like the M5100 is an HG cassette instead of MS, so probably not applicable in your case.