Wee Sprocket

[Gummo]

The wee sprocket on my Shimano CS-HG500 10-speed cassette (11-34T) is causing the chain to skip on every chainring, so despite the cassette being less than a year old it is disappointing. I've tested the chain and it's in good order, ityself being less than a year old.

My question is: how can I be sure to buy the correct sprocket for the cassette?

 

[Ajax Bay]

Do you reckon you use the 11t sprocket quite a lot, because it is normally a lightly used one?
Any spare 11t sprocket will do, eg from another cassette that you have held onto for 'r'on. Doesn't matter if it's 11sp: the RD will be limited by the H limit screw. Your LBS might let you have one from their bin.

 

[davidphilips]

Would be very surprised if its worn, perhaps problem is down to cable adjustment, may have one if needed as tbh very seldom use an 11t sprocket

 

[Dogtrousers]

I have no advice (other than to rather unhelpfully say "so don't use that one") but you might want to read this recent thread
https://www.cyclechat.net/threads/chain-skipping-on-smallest-sprocket.291600/#post-6966847

 

[Ajax Bay]

I . . . rather unhelpfully say "so don't use that one"

Give than man kudos for consistency.

 

[Dogtrousers]

Give than man kudos for consistency.

I'm just following the teachings of the great sage Tommy Cooper.

"Doctor, it hurts when I do this"
"So don't do it"

 

[Paulus]

Is the rear mech going over sufficiently to allow the chain to sit on the sprocket fully? Either the limit screw needs a tweak, or the cable needs adjustment.
Is there any obstruction sitting in the gap between the 11T and the 12T sprocket?

 

[Ming the Merciless]

Slightly stiff link, skipping on the tighter radius of the smallest sprocket ?

 

[Ajax Bay]

Basically 11-speed wheelsets need a cassette spacer to go on the freehub before the cassette so it fits properly.

. . . have a look at the latest postings in the Bargains thread for a Superstar Components wheelset. I picked up one of the ones they had left, paying £52 in November. It's now £37.50 with their 75% discount code 75WHEEL.

I've just bought the wheelset at £37.50.

Is the cassette on this wheel? Did you use both the 1mm spacer and the 1.8mm spacer? Does the lock ring engage at least two full turns?
Check there's clearance with the chain on the 11t, between the chain and the drop out. If mudguards check securing screw (inner end).

 

[Gummo]

First of all, thanks for your kind suggestions. I'm afraid my cup of shame runneth over. Something I've never seen before in all my years of cycling - a hardened disc of gunk firmly attached to the cassette lockring - can only mean the chain was bouncing off that.

An extra unexpected occupational hazard in the life of a nature-loving photographer habitually in very dirty circumstances.

Thanks again for your time and knowledge.