New cassette & chain rattling in middle gears?

[Deleted member 89023]

Hi All, I've just replaced a worn cassette & chain (see previous post) but the bike still makes a noise in the middle gears. The new cassette is a fixed unit (apart from the two smallest sprockets), so there should be no unevenness between the middle sprockets. I've lubricated the new chain & cleaned the rear derailleur, so I'm thinking it's either a case of adjusting the B Screw on the rear mech, or the front chain wheel - which I haven't replaced in over 2000 miles - is worn? Any suggestions? Many Thanks.

 

[screenman]

When was the last time that you checked the rest much for alignment, I can guess the answer.

 

[Paulus]

Quite possibly the indexing needs a tweak.
I'll take it that the new chain was the equivalent length of the old one, so leave the B screw alone for the time being.

 

[Ajax Bay]

Chain ring is not worn, nor cause of symptom.

 

[Deleted member 89023]

Quite possibly the indexing needs a tweak.
I'll take it that the new chain was the equivalent length of the old one, so leave the B screw alone for the time being.

Yes, the chain is same length as the previous.

 

[fossyant]

Check the indexing.

 

[Deleted member 89023]

Quite possibly the indexing needs a tweak.
I'll take it that the new chain was the equivalent length of the old one, so leave the B screw alone for the time being.

Check the indexing.

Because the gears were shifting fine with the bike on the stand it didn't occur to me that could be the problem.

 

[fossyant]

Chain in under load whilst riding, so may shift a tiny amount in comparison to on the stand. Go take a look from behind, low down and see if the top jockey is perfectly aligned with one of the sprockets.

Also, there is a chance the gear cable is grubby - check how smooth the rear 'loop' is running.

 

[Deleted member 89023]

Chain in under load whilst riding, so may shift a tiny amount in comparison to on the stand. Go take a look from behind, low down and see if the top jockey is perfectly aligned with one of the sprockets.

Also, there is a chance the gear cable is grubby - check how smooth the rear 'loop' is running.

Cable is new, will check indexing and RD.

 

[fossyant]

Some cassettes can sit slightly different on the freehub, and even a fraction of a mm can cause a rattle. Always make sure the cassette is indexed to the middle sprockets. Check the jockey wheels aren't overly worn - bearing/bushes too.

 

[Fastpedaller]

A couple of weeks ago I renewed the chain and rear derailleur cable on my bike (old one was less than 3% but I wanted a chain for an 'occasional use cheap beater so it made sense not to put new chain on beater)..... Anyway, on first ride it would sometimes change to next sprocket, and I fiddled with the cable adjuster during the ride but no joy. On getting it home and in the stand it became clear it would work fine in the stand, but viewing the alignment as described by Fossyant showed it wasn't good. Once good alignment was restored it was ok on the road. Regarding the B-screw..... I've found from bitter experience it's always best (if there's a problem with new parts) to never adjust anything or replace anything that wasn't changed in the last session or it ends up even worse.

 

[fossyant]

One other point, you've not forgotten the spacer, and the cassette is tight and not wobbling.

 

[Ajax Bay]

One other point, you've not forgotten the spacer, and the cassette is tight and not wobbling.

Why would the OP need a spacer on this cassette?
https://www.cyclechat.net/threads/doe-my-cassette-look-worn.300090/

 

[faster]

Why would the OP need a spacer on this cassette?
https://www.cyclechat.net/threads/doe-my-cassette-look-worn.300090/

He'd need a spacer if the cassette wasn't being clamped tightly between the freehub and the lockring.

 

[Ajax Bay]

The OP would need a spacer if this 9sp cassette was being fitted onto an 11sp freehub (it isn't).