Small Indexing Problem

wilky27

Hi all.

I've just upgraded my rear derailleur and I'm having some issues indexing it correctly. When I'm on the small ring (front) it changes up and down as smooth as a babies behind, but when I'm on the big ring I'm having a few issues. It sticks in gear 2 and jumps into 4. If I adjust this using the barrel it skips gear 9. Plus the general changing in the other gears is really clunky.

It may seem like an extremely small issue but it's driving me around the bend, especially after spending money upgrading. Any advice is massively appreciated.

Thanks,
Wilky.

ride_whenever

is the chain too short?

wilky27

err could be, although its the same chain that was on before i swapped my derailleur. How do I find the correct length?

wilky27

Could it be the chain is slightly too long? There's is a tiny bit of wear!

zx6man

has the new rear mech got a longer cage? what is the upgrade

wilky27

No I don't think so. It was a campag xenon to a campag centaur! Both short cage.

thanks.

g00se

Xenon 9 or Xenon 10?

If it was 10, then it should be OK.

wilky27

10 yeah.

g00se

OFFICIALLY, since 2011, 10-speed kit is not backwards compatible - the rear mech on the newer stuff uses the same parallelogram from the 11-speed kit - so the cable pull required is slightly different. However, all the anecdotal evidence is that it works OK. especially as it's OK on the small ring.

As it occurs when going big to big, could it be a chain-tension issue? How old is the chain and is it warn? Could one of the chain ring bolts be loose (sounds odd but when that happened to me, it presented itself as sloppy rear shifting)? Make sure the chain isn't touching the front mech at that angle.

wilky27

Hi goose,

Cable pull from the levers? I have ordered some centaur levers too, not installed them yet though.

There is some slight wear on the chain, 0.5 falls through but 0.75 doesn't when using my park tool chain checker.

not sure about the chain ring bolts. Will check!

Chain isn't touching the front mech.

g00se

It's a bit unclear from what Campag have said, but they basically decided to use the same rear mech parallelograms on the 10-speed powershift groups as the 11-speed stuff. In getting one of these mechs to move the cage over the gap of two sprockets, it uses a minutely different amount of cable pull compared to the older 10-speed kit.

So, the rules say, if you've got 2010 and older 10-speed kit, it's all compatible with itself. For the 2011+ stuff, you can only use the powershift mechs and levers.

However, it appears that they're so close, that those that have mixed them, say there isn't any problems.


By the way, there were new shape Veloce and Centaur levers and mechs in 2009 and 2010 that still used the old dimensions (the ultrashift stuff). They also had the ultrashift thumb levers like the current Chorus, Record and S Record groups. They had the older style group logos on them.

g00se

But for all that waffling, I say it's probably worth replacing the chain too. According to Sheldon Brown.

0.5% (1/16") chain wear = chain stretched, replace it but the sprockets should be OK.

0.75% (3/32") chain wear = sprockets probably starting to wear too. A new chain will not last as long as the damaged sprockets will wear the new chain more quickly.

1% (1/8") chain wear = sprockets warn, much past it and a new chain will likely skip so will need a new cassette too.

wilky27

KMC Chain ordered. With this and my new levers it will hopefully sort it!

Thanks for your help goose!!

wilky27

Quick one, should I cut the chain to the same length as the old chain? (obviously minus the wear)

g00se

Would be fairly safe (don't forget you get the extra link from the KMC quicklink too). That or this:

http://www.parktool.com/blog/repair-hel ... gth-sizing

For which, you can do the rigorous equation here without the maths:

http://www.machinehead-software.co.uk/b ... hcalc.html

wilky27

Cheers!

wilky27

The new chain didn't solve my issue. Installing the new levers tonight so fingers crossed!

wilky27

Nope, same issue. Looks like it's going to the shop!

Weird thing is my adjuster barrel doesn't seem to be working.

sancho_uk

Wilky, I had a similar issue and after having the bike in the shop cause it was driving me mental as it is you by the sounds of it, they said i had a slight bend in my Rear Mech Hanger.

The have bent it back to how it should be and now shifts like a dream! I didnt fancy bending it myself cause knowing my luck it would of snapped!

Could be worth a shot. I have now ordered a spare hanger just in case it goes again

wilky27

Ah, that could be it.

Out of interest which shop did you take it to? One in Warry??

Thanks!

sancho_uk

CycleHouse

Round the back of Tesco, great shop and the chaps there are really helpful

wilky27

Cheers Sancho!

sancho_uk

Don`t thank me yet mate its not fixed ha

Hopefully that will sort it though good luck!

wilky27

I've fixed it!!!

I fixed the inner cable to the wrong side of the clamp as it came out of the barrel adjuster so it was coming out at a slight angle. Small things eh!

Heard good things about that shop though. My brother had a service there and another lad I know has just had a bike fit that's improved his riding position. Might pop in this weekend.

zx6man

Good man.