Indexing gears. Fine in the workstand; terrible on the road.

[Kajjal]

Just got my gravel bike back from the LBS after it's first service. I mentioned there was some chain chatter, which they duly fixed. When I bought the bike, I ordered a spare set of wheels to run road tyres (plus matching cassette and discs to the stock wheels that have gravel tyres on), on to essentially make it a dual use bike.

I subsequently swapped over to my road wheels and got it on the work stand to realign the brake calipers and index the gears. Got it all nicely done, all shifting smoothly.

Took it out for a 15 mile ride at lunch. First 6-7 miles, living the dream. Then I noticed a little chatter, which eventually became a ridiculous ride where any of the middle gears wouldn't run smoothly. Initially under load when climbing, but then became permanent regardless of terrain.

I stoopped to test, shifting up, no problems. Shifting back down, 11 to 10 to 9 to 8 was ok, but 8 to 7 wouldn't shift, and 6-4 I got a bunch of jumping around, chain not settling at all. I stopped to adjust the barrel 1/4 turn ACW, and then again another 1/4 but this did nothing.

Any ideas why this would happen? Advice greatly appreciated.

My gravel bike when new did the exact same thing, took it back to shop and they fixed it. It started happening during a 50 mile mainly off road ride , have no idea what they did to fix it. As the bike was new I just took it into the shop for them to sort out. Been fine ever since on or off road.

 

[T4tomo]

It was a b*****d to get back on, in the end I ordered their reconnecting tool to aid,

The missing link came with the bike so I have to assume the lbs set it up without breaking it other than to shorten as required out of the box.

? but you took the chain off at come point?

 

[lazybloke]

? but you took the chain off at come point?

That puzzled me too; no need to break the chain to change wheels.

 

[Ian H]

If it's not changing properly in one direction or over certain sprockets, then it is highly unlikely to be the chain.
Assuming the cable is in good order and the cassette is properly tightened, it's most likely to be dirt. You can clean the rear mech by putting it in the smallest co then manually pushing it up and down the range as you turn the pedals. Use WD40 or something to clean it as you work it. Then check under bottom-bracket guides for cleanliness, and anywhere else where the cable bears. Finally, adjust the gears and road-test.

 

[livpoksoc]

That puzzled me too; no need to break the chain to change wheels.

Ah sorry, did it to clean the chain. It got gunked up on a gravel ride.

 

[livpoksoc]

This afternoon I put it on the workstand and the chain wasn't settling the same way as it had been on the road. In the end I gave it a full turn and a half more on the barrel adjuster and it settled on the stand.

I just took it on a club ride for 25 miles and was absolutely golden, so I assume it might have just been the two relatively new components getting acquainted with one another as opposed to any bigger problems.

 

[livpoksoc]

Thank you all for your contributions though. Good to read some of the possible problems to look for if I get issues down the line.

 

[MontyVeda]

haven't had to re-index my gears since last putting a new cable on, so 10, maybe 12 years ago... however, I always found they needed a little tweak on the bar adjuster when riding for the 1st time, despite indexing perfectly in the workshop (kitchen).