Bad shifting in 1 single cassette gear

quozl

I have poor shifting into the 2nd smallest sprocket (13) on my rear cassette

Shifting is slow shifting into it from both directions.

I checked my derailleur hanger, it's fine. Indexing is fine (I believe - I've checked, tweaked ad naseum) and all other gears are good.

The sprocket looks ok to me but the only thing I can think of is that that single sprocket is worn out? It would probably be the sprocket that I use the most - either that or the 12, as I spin a high cadence in my small chain-ring all the time unless descending. Cassette probably has about 3000 km on it.

There is no slipping once I'm in the gear though. It's just difficult to get into.

Any other suggestions on what could be wrong? What should I be looking for on the sprocket that would affect the shifting? The teeth look ok to me but I don't know that I'd spot a minor difference.

I guess the next thing to try is to swap cassettes and see if the replacement one also complains at the 2nd smallest sprocket or not.

Bummer to have to replace a whole cassette for 1 sprocket which works fine apart from shifting but it's starting to annoy me

07Lapierre

If your sure the indexing is adjusted correctly, then I'd check/replace the cable (inner and outer) and re-adjust the indexing. If that doesn't work, then it could be a worn chain and/or a worn Rear derailler.

I had a similar problem before, and I ended up replacing the RD to resolve the problem.

WillyFXP

quozl wrote: »

I have poor shifting into the 2nd smallest sprocket (13) on my rear cassette

Shifting is slow shifting into it from both directions.

I checked my derailleur hanger, it's fine. Indexing is fine (I believe - I've checked, tweaked ad naseum) and all other gears are good.

The sprocket looks ok to me but the only thing I can think of is that that single sprocket is worn out? It would probably be the sprocket that I use the most - either that or the 12, as I spin a high cadence in my small chain-ring all the time unless descending. Cassette probably has about 3000 km on it.

There is no slipping once I'm in the gear though. It's just difficult to get into.

Any other suggestions on what could be wrong? What should I be looking for on the sprocket that would affect the shifting? The teeth look ok to me but I don't know that I'd spot a minor difference.

I guess the next thing to try is to swap cassettes and see if the replacement one also complains at the 2nd smallest sprocket or not.

Bummer to have to replace a whole cassette for 1 sprocket which works fine apart from shifting but it's starting to annoy me

I had exactly the same issue with a brand new cassette, although it was a different cog, swapped the chain from shimano to KMC, problem solved.

quozl

WillyFXP wrote: »

I had exactly the same issue with a brand new cassette, although it was a different cog, swapped the chain from shimano to KMC, problem solved.

Very interesting.This started happening pretty recently and I'd forgotten that I swapped from my usual mavic chains to a shimano one about a month earlier. I was assuming bad indexing at first and it's only the last week that I've really throughly gone over the indexing.

So that might well be the answer.

Feck it if it is, what a waste of money on the (admittedly cheap) chain.

joxerjohn

I'd go with the cables and outers needing attention as the likely culprit before you ditch the chain. When were your cables last replaced ?

quozl

Cables and outers are the same ones I put on when I built the bike about 5,500km ago but I have given them a good clean and don't get how that would result in the bad shifting on just one sprocket?

Maybe though you're right and it is time to change them. Plus I did just get a new park tools cable cutters in the post today

Type 17

Get rid of the Shimano chain ASAP, anyway - it might fix the sprocket issue, but more importantly, it will wear out much quicker than other chains (wearing your cassette out with it). Also, if you ride hard, you may find that the Shimano chain develops multiple cracks on the side plates, which can lead to chain failure. Here's a chain I replaced for a customer after less than a year's (admittedly hard) use:

07Lapierre

I use Shimano chains...i've had no issues with them. All chains wear out.

Type 17

Perhaps some Shimano chains are good, but it seems to me that at least some models (or some batches?) wear much faster than other chains (from personal experience, and from working in bike shops).

The bad ones seem to have soft pins (faster wear, meaning stretch) and brittle side plates, like the ones in the shots above - although this is the worst one I've seen, there have been many others with some cracking.

Of course all chains do wear out, but some wear noticeably faster than others...

Zen0

Change the cable and outer. It could be a single loose strand on the cable, but you risk messing up your shifter if you leave the problem to get worse.

granda

Type 17 wrote: »

Perhaps some Shimano chains are good, but it seems to me that at least some models (or some batches?) wear much faster than other chains (from personal experience, and from working in bike shops).

The bad ones seem to have soft pins (faster wear, meaning stretch) and brittle side plates, like the ones in the shots above - although this is the worst one I've seen, there have been many others with some cracking.

Of course all chains do wear out, but some wear noticeably faster than others...

dont mean to hijack this thread but what preferences do people have for chains, personally i've always used shimano ultergra and never had any problems

07Lapierre

granda wrote: »

dont mean to hijack this thread but what preferences do people have for chains, personally i've always used shimano ultergra and never had any problems

"If it's not broke, don't fix it"

smacl

quozl wrote: »

I have poor shifting into the 2nd smallest sprocket (13) on my rear cassette

Shifting is slow shifting into it from both directions.

Have you taken the RD off, cleaned and lubed it, and checked that it moves smoothly through its full range? A bit of grit or build up of crud either in the mechanism or spring could be impeding it at that cog position. I find cleaning the RD on the bike sometimes has the effect of pushing crap further into the mech rather than removing it.

Re indexing, I find it is best done with the bike on a turbo, as the work the mechanism has to do under load is different than without a load.