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?

[Eyebrox]

Sure it's not a tensioning issue or the H limit screw needing adjusted? If there's a rogue tooth on the smallest cog you can straight it with a chisel or long nose pliers or file it down.

[keyboardmonkey]

Personally, I would only use the 11T sprocket whilst on the largest chainring, but if the chain is skipping whilst on ‘every’ chain ring is it possible that until recently you have rarely if ever used the 11T sprocket? Mine sees very little service.

If your chain has worn over use during the past twelve months along with all the larger sprockets, and then you drop the chain on to the smallest sprocket, you should expect it to skip; this is why you can get way with pairing a new chain with a slightly worn cassette, but shouldn’t put a new cassette on your bike and leave a part worn chain in place. Just a thought.

[TheBomber]

Do you have the right lockring? Some aren’t compatible with 11sp and will prevent the chain from sitting on the teeth correctly.

[531colin]

If the chain and cassette are both less than a year old, and it all used to work together and now it doesn't work, then something has changed and its unlikely to be wear, because they wear together.
As somebody already said, try backing off the top gear limit screw "H" a quarter of a turn at a time for up to a whole turn. By the same token, make sure the chain can't overshoot the big sprocket and go into the spokes. (Tighten the "L" screw to make sure if theres any doubt)

By the way, can you buy single sprockets these days? It used to be a difficulty years ago when I wanted some individual sprockets.
It they are any use to anybody, I have a few from my days of assembling cassettes with my own ratios;
8 speed 11, 13, 15, 17, 20, 23, 26
9 speed 11, 13, 15, 17, 20, 23

[mattsccm]

If it is damaged then scrap cassettes from shop bins may help. The 11 rarely wears as it get little use unless you have small chain rings.
It is usually also an awful mix with an inner ring as most set ups allow enough chain to prevent damage with occasional big to big cross training. This can be too loose to make little to little be nice even if you did chose to use it. Not universal but enough to make a bin raid worth a try.

[mattsccm]

Checkedmech hanger alignment? Small sprockts are less forgiving.

[iandusud]

Do you have the right lockring? Some aren’t compatible with 11sp and will prevent the chain from sitting on the teeth correctly.

I have come across this using the lockring supplied with the new cassette!

[Redvee]

Do you have the right lockring? Some aren’t compatible with 11sp and will prevent the chain from sitting on the teeth correctly.

I have come across this using the lockring supplied with the new cassette!

When 12-28 etc was the norm this wasn't an issue but when 11-28 etc came along you had to make sure you had an 11t lockring as they are slightly smaller than a 12t lockiring.

[Mick F]

11t sprockets are an abomination.

Either buy a new sprocket - I bought three - and replace it.
This is what I did with my 11-28 10sp until I'd used up the three, then bought a 12-30 instead. Much much better.
Yes the top gear is lower, so buy a larger chainwheel - much better investment than another stupid 11t cassette or endlessly buying 11t individual sprockets. You can even sell your old chainwheel to part fund the new chainwheel - nobody wants a worn sprocket.

The fewer the teeth on a sprocket, the more the teeth wear. Goodness knows how bad a 10t or 9t are!

[Mick F]

I bought my 11t sprockets from here, from advice on this very forum.
You only pay for shipping once per order, so buy as many as you want. I picked three as it seemed a good bet.

https://www.bike-discount.de/en/shimano ... m771-10-bl?

[Jdsk]

I bought my 11t sprockets from here, from advice on this very forum.
You only pay for shipping once per order, so buy as many as you want. I picked three as it seemed a good bet.

https://www.bike-discount.de/en/shimano ... m771-10-bl?

€2.94/ sprocket.

But:

For customers from Great Britain (except Northern Ireland) the following conditions apply:
For customers from Great Britain there is a minimum order value of 175 GBP incl. shipping costs. Unfortunately, it is currently not possible to ship complete bicycles and bulky goods to the UK.
https://www.bike-discount.de/en/service ... -customers

Jonathan

[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.