How to get gears to index

[Deleted member 35268]

Hi, my rear Shimano Ultegra on a 9 speed cassette (and triple mech upfront) is jumping the smaller gears.

I have just replaced the chain, with a correct 9 speed, and the gear cable snapped in the week so that is new too.

The cassette was not replaced at the same time as the chain as it is newish (2000 miles ?)

With all the new bits, my shifting is in a mess.

The smaller cogs are jumping (necessarily under load) - which tells me the Cassette may be OK.

I know the limiters are not going to help with indexing, and the b-tension adjuster won't help either - which just leaves me with the cable adjusters at the shifters and at the rear mech.

Am I on the right track to adjust the cable adjusters to tweak the indexing?

Failing that, I will take it to my LBS.

 

[Dogtrousers]

Have a look at this

 

[boydj]

Re-indexing is simple to do starting from scratch. Shift the gears to get the chain on the smallest cog then disconnect the cable at the mech. Screw the cable adjuster on the mech all the way in and then back it out 1 turn. Using pliers to pull the cable reasonably tight, re-connect the cable at the mech. Now try the shifting - it should be pretty close to correct, and some fine-tuning on the adjuster should get it spot on.

I'm concerned that the chain jumping may be due to a worn cassette. It may not have done a big mileage, but if it has been used for a while with a worn chain, then it may have worn to fit the chain and will then have problems with a new chain.

 

[Deleted member 35268]

Yeh, I think the cassette is probably dead too.

Can a visual inspection be accurate on a cassette?

 

[Cyclist33]

On the assumption that the "first month" or "six week" first service that most bike shops offer on new bikes is usually marketed as mainly to reindex the gears after the initial cable stretching period, maybe you need to let the new parts bed in for a few weeks riding and then reindex from scratch?

I dunno.

 

[Hacienda71]

Yeh, I think the cassette is probably dead too.

Can a visual inspection be accurate on a cassette?

Imho no. I have replaced a chain and left a cassette which looked fresh and hadn't done many miles and it slipped with the new chain. A worn cassette tends to manifest itself with a slipping chain in certain gears when power is applied rather than jumping, which would happen with little or no load and is down to fine adjustment of the rear mech.

 

[yello]

Must admit that my first thought was the cassette. I thought your assumptions about limit screws was spot on and whilst playing with barrel adjusters might help, I think it unlikely.

I reckon cassettes and chains can meld (or some such) over a period meaning a change of one requires a change of the other to ensure clean shifting. That's my experience anyway though admittedly at a greater milage.

 

[Deleted member 35268]

Cassette going to cassette heaven