Loose cassette

[Nickolp1974]

On my merida e120 900e so where on di2 XT I've been jumping about in 11th (Oh bikes done around 850km) and then more recently 10&11 so just just chain and it's pretty much 0.9 so defo needs replacing. Thought I'd check for wear on cassette and that ain't brilliant but also the whole things loose which has obviously caused havoc with the drivetrain. I always look after my gear and never had this issue before but I've never had an ebike but I understand there will be greater wear and strain. Now should it of got loose or is it a return to shop warranty issue??

 

[Benson]

Tighten it up! Depending on usage and whether it was properly torqued up it isn’t beyond the realms of possibility for it to work loose. It’s also possible a loose cassette could prematurely wear the chain. I wouldn’t think it’s a warranty issue.

 

[Wernher]

On my merida e120 900e so where on di2 XT I've been jumping about in 11th (Oh bikes done around 850km) and then more recently 10&11 so just just chain and it's pretty much 0.9 so defo needs replacing. Thought I'd check for wear on cassette and that ain't brilliant but also the whole things loose which has obviously caused havoc with the drivetrain. I always look after my gear and never had this issue before but I've never had an ebike but I understand there will be greater wear and strain. Now should it of got loose or is it a return to shop warranty issue??

First off your wear seems excessive. I got 1800 km on my Giant with .75 wear. Incidentally both bikes use the same KMC chain that I found to be very durable and your bike has an XT cassette, mine is a SLX cassette. After the first chain was worn to .75 I did replace my cassette with a SunRACE cassette. Reason is my first one was replaced immediately as it was bent on deliver and the second one broke a tooth on the second gear so I lost confidence in the SLX cassette and I preferred the more even spacing between the gears on the SunRACE. My second chain (a Shimano eBike specific chain) on the new cassette wore faster and only lasted about 900 kilometres with the same care and lubrication. I'm still on the SunRACE cassette but back on the KMC chain and so far wear seams to be similar to the first chain.

As far as your loose cassette is concerned. That's not good and will lead to damage and probably excessive wear and bad gear changes. We also found that gear changes become less accurate and precise if the chain becomes dry and if you use dry lube, which we prefer here as a result of the dry conditions, you have to apply it more frequently than oil or wet lube. You need to look at why the cassette is loose because it may be more than just working loose. It could be a failure on the freewheel hub or hub itself. Either way you're probably in for a new cassette and chain at that percentage wear. Best to maintain and replace the chain earlier with less wear as it works both ways. If the cassette is worn too much it starts to wear the chain faster as well. Emtb's eat chains faster than normal bikes. More power and more weight.

 

[Nickolp1974]

Tighten it up! Depending on usage and whether it was properly torqued up it isn’t beyond the realms of possibility for it to work loose. It’s also possible a loose cassette could prematurely wear the chain. I wouldn’t think it’s a warranty issue.

I'd agree with tightening it up but now there's quite a few teeth missing and I need a new chain, so should I pay for that???

 

[Nickolp1974]

First off your wear seems excessive. I got 1800 km on my Giant with .75 wear. Incidentally both bikes use the same KMC chain that I found to be very durable and your bike has an XT cassette, mine is a SLX cassette. After the first chain was worn to .75 I did replace my cassette with a SunRACE cassette. Reason is my first one was replaced immediately as it was bent on deliver and the second one broke a tooth on the second gear so I lost confidence in the SLX cassette and I preferred the more even spacing between the gears on the SunRACE. My second chain (a Shimano eBike specific chain) on the new cassette wore faster and only lasted about 900 kilometres with the same care and lubrication. I'm still on the SunRACE cassette but back on the KMC chain and so far wear seams to be similar to the first chain.

As far as your loose cassette is concerned. That's not good and will lead to damage and probably excessive wear and bad gear changes. We also found that gear changes become less accurate and precise if the chain becomes dry and if you use dry lube, which we prefer here as a result of the dry conditions, you have to apply it more frequently than oil or wet lube. You need to look at why the cassette is loose because it may be more than just working loose. It could be a failure on the freewheel hub or hub itself. Either way you're probably in for a new cassette and chain at that percentage wear. Best to maintain and replace the chain earlier with less wear as it works both ways. If the cassette is worn too much it starts to wear the chain faster as well. Emtb's eat chains faster than normal bikes. More power and more weight.

This was my thoughts as I've not had one loose before. I've not had the cassette off thought I'd leave that to the bike shop as the freehub etc will need checking.
I know they eat through chains which is why I thought it was skipping. I never change gear under load, like I said I'm always carefully to prolong the lifespan of the drivetrain. Always degreased and oiled correctly.

 

[Gary]

but now there's quite a few teeth missing and I need a new chain, so should I pay for that???

You continued riding knowing your cassette was loose on the freehub?

 

[steve_sordy]

I had loose gears on a Shimano cassette. The rivets on the spiders had sheared and several rings were loose as a consequence. That was a warranty claim. Once I had sent pictures, the claim was paid without quibble by Chain Reaction Cycles.

 

[Nickolp1974]

You continued riding knowing your cassette was loose on the freehub?

No, at the time just thought I needed new chain, only when i checked chain also inspected cassette for wear as no point replacing one and not the other.

 

[Benson]

I'd agree with tightening it up but now there's quite a few teeth missing and I need a new chain, so should I pay for that???

Nah, new bike time ??

 

[2unfit2ride]

Any updates on this, did you find the cause?
I just changed my chain at 600 odd miles & nearly .75 wear, I bought a KMC, hope it lasts longer but it was only £20.
Cheers.

 

[Nickolp1974]

Any updates on this, did you find the cause?
I just changed my chain at 600 odd miles & nearly .75 wear, I bought a KMC, hope it lasts longer but it was only £20.
Cheers.

No mate, no stand out cause found. Been fine since new cassette and chain, just made sure the new one was nice and tight.