Indexing my rear gears.

webboo

I struggling to get my rear gears indexing correctly 10 speed shimano. When I change up the cassette I.e. Going into a bigger sprocket , it seems to have gone past as when I click to go down it is then correct. Does need more tension on the cable or less.

StillGoing

Your description isn't very clear so to start from basics.

With the cable disconnected, the top jockey wheel of the derailleur should sit directly underneath the biggest sprocket on the cassette when you push it across. If it isn't, adjust the L limit screw until it does. Let the chain move back so the jockey wheel is under the smallest sprocket and it should sit just outside i.e. towards the derailleur. Again, if it doesn't, adjust the H limit screw. Wind the barrel adjuster all the way in, then 2 turns out, ensure the shifter is clicked all the way to the highest gear position, pull the cable inner all the way through the derailleur and attach it. You shouldn't need to apply additional tightness by pulling the cable to clamp it. Check the shifter moves through all the gears and dial any noise out with the barrel adjuster making small turns until the noise disappears.

arlowood

In addition to the advice above on lining up your high and low limits - have a look at this video

https://www.youtube.com/watch?v=SkzvfCaIbyQ

One of the better ones out there

nuclearred955

Unless you've changed your rear wheel or cassette, it's highly unlikely your limit screws will need any adjustment - they don't tend to move on their own.

For Shimano mechs, get the cable sufficiently tight that each click moves the chain one sprocket, than fine-tune it by shifting to the middle of the cassette, then adjust cable tension so the jockeys line up fractionally inboard of the sprocket you're on.

If that doesn't sort it, then you're maybe looking at worn chain/sprockets, worn cable or a bent derailleur hanger.

webboo

Limit screws are fine, it's when I click up. It's almost going up 2 sprockets, so I can hear it's not running right. Click to go down and it doesn't drop a sprocket but it's now in line.

StillGoing

Webboo wrote:

Limit screws are fine, it's when I click up. It's almost going up 2 sprockets, so I can hear it's not running right. Click to go down and it doesn't drop a sprocket but it's now in line.

As stated, your first description is unclear of what the problem is so I've suggested going back to basics and re-indexing from scratch. Doing so will also enable you to find out if the cable inner is sticking anywhere.

But, if you don't want to do that, change into your smallest gear. Change down counting the clicks until you get to the gear where you're having problems. If it is jumping up too many sprockets, you need to take some of the tension off with the barrel adjuster. If it isn't changing up, you need to tighten it.

rolf_f

Once the limit screws are fine, my approach is to make sure the cable adjuster is in mid adjustment and then free the cable. Pull the cable taut with a pair of pliers and reclamp to the mech. Then do what your gear manufacturer recommends to index - for Campag I go to the fouth sprocket up and ensure that chain sits centrally between the sprockets on either side (helps to have a light background behind the bike whilst doing this). Then recheck that you still have all gears (possibly you've turned the cable adjuster the wrong way if you hadn't done a good job taking up the tension in the first place!)

Of course, if you have done a lot of miles in bad weather on the bike, then you should also change the cable outer to the rear mech which gets a lot dirtier than the others and can really mess up the indexing even if all of the settings are correct.

hububalli

Could be your hanger is misaligned. If you don't have the tool your LBS can check it for you. I spent hour trying to get my rear indexing sorted on a new bike and it turned out to be a misaligned hanger.

Bobbinogs

arlowood wrote:

In addition to the advice above on lining up your high and low limits - have a look at this video

https://www.youtube.com/watch?v=SkzvfCaIbyQ

One of the better ones out there

Blimey, he made that seem nice and easy. Excellent vid, watching it should be a compulsory part of every bike purchase!

webboo

After watching that video. I could get the changes going up the cassette perfect but alas then it wouldn''t drop down. So it looks like new inner and outer cables are needed.

gozzy

Bobbinogs wrote:

arlowood wrote:

In addition to the advice above on lining up your high and low limits - have a look at this video

https://www.youtube.com/watch?v=SkzvfCaIbyQ

One of the better ones out there

Blimey, he made that seem nice and easy. Excellent vid, watching it should be a compulsory part of every bike purchase!

It's the video I always point people too who are stuck with their gears. Never fails.

rolf_f

Webboo wrote:

After watching that video. I could get the changes going up the cassette perfect but alas then it wouldn''t drop down. So it looks like new inner and outer cables are needed.

No, not necessarily. As I said, it may just be that the outer to the rear mech needs changing. And you certainly don't need to change the outers every time you change the inners - takes a while for the outers on the bars to need changing.

Also, the guide under the bottom bracket can affect shifting if you don't keep it clean.

sebbyp

you might still want less tension. tension on the cable moves the chain towards the wheel (bigger cog!) . wind the adjuster at the rear mech clockwise if looking from behind the bike. turn it a tiny tiny turn until its correct. They are really sensitive I have found. You can turn a quarter turn at a time I think. degrease and lube the chain too, can help alot!

EDIT: Check the cable is not frayed when it turns sharply into the top of the shifer, peel back the rubber on the shifters and have a good look. the cable doesnt release if it is frayed. happened to me

webboo

As I said I can get it shift up ( lower gears/ bigger sprockets) but then one click to go down bigger gear but it doesn't quite go. I spent about an hour but I could only get to shift well one way at I.e it went up the cassette with one click but not down or one click to go down but it wouldn't go up with one click.

sebbyp

like I said, ultra bleeding sensitive. very small adjustments! or another problem, frayed cable, bent hanger. etc.

arlowood

Webboo wrote:

As I said I can get it shift up ( lower gears/ bigger sprockets) but then one click to go down bigger gear but it doesn't quite go. I spent about an hour but I could only get to shift well one way at I.e it went up the cassette with one click but not down or one click to go down but it wouldn't go up with one click.

Strikes me as a typical issue with the inner/outer cable being fouled up or possibly the derailleur parallelogram being gunged up or the spring being shot in some way.

When you're changing from a smaller to a bigger sprocket you are using the positive action of the shifter to pull the cable and move the derailleur chain guide inwards. When you flick the inner paddle to move the chain from a bigger to a smaller cog you are relying on the spring tension in the derailleur parallelogram to pull the chain guide back towards the smaller sprocket.

The symptoms you describe indicate that the inner cable is fouling somewhere so that the spring tension is not strong enough to make the upward shift properly.

As a first option try disconnecting the inner cable and remove it from the rear outer (rear mech to chain stay cable stop). Make sure the shifter is clicked all the way to the highest gear (smallest sprocket). Pull the hood back on the shifter to expose the cable insertion hole and push the inner out sufficiently so that you can grip the cable end nipple. Get some teflon spray or similar lubricant and spray the inner liberally as you pull it back and forward a few times. Pull it back into the shifter housing and make sure it is properly seated. Then re-thread the inner through the rear outer and go through your indexing procedure again.

At the same time you could try de-greasing and lubricating the derailleur parallelogram and spring.

If, after that, you still have problems then think about trying a re-cabling exercise

SME

What initiated the problem in the first place - have you changed a cable, cable outer, chain, sprockets, mech? Or is it just a problem that's developed - wear and tear?

If you set your limits screws OK and on the small cog the cable is just about tensioned (not tight at all and not sloppy) then you should be able to index your gears OK. Do check that your cable is running quite freely in it's outer cable sheath and that there's no drag - as mentioned, such things as dirt under the bottom bracket can cause this.

If you're having trouble shifting down the gears ie small to big cogs, then turn the little adjuster anticlockwise, 1/4 turn at a time (it should click in place). If you're having trouble shifting up the gears (big to little cogs), turn the adjuster clockwise 1/4 turn at a time.

webboo

Thanks for all the replies. I will try a new outer cable sheath on the rear mech to see if that's the problem.