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

[livpoksoc]

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.

 

[bikingdad90]

Sounds like a new chain with a worn cassette on your commonly used gears or vice versa? Usually a mismatch can cause this issue.

The other things that can sometimes cause these issues are a stiff link causing the chain to ride up and a bent mech hanger.

 

[roubaixtuesday]

As well as the good suggestions above, if it's shifting OK one way but not the other, a sticking cable is often the culprit.

In order of likelihood of solving:

1. Bodge by squirting as much wd40 as you can inside the outers and hope for the best.

2. Replace the cable as well

3. Replace the outers as well as the cable.

(1) normally works ime, (2) if its a frayed cable, (3) is best but a lot more work.

 

[ebikeerwidnes]

Probably not relevant if it has just come back from the LBS
but I have a similar problem from time to time
I generally find that giving the chain and whole gears system a damn good clean sorts it out
Last time I did it (a few weeks ago) changing to the most used gear took an age and involved a lot of clatter

when I cleaned it I discovered that, apart from general gunk all round the derailleur cogs - the chain was VERY stiff in places
A good clean through a chain cleaner and a good lube followed by a short ride sorted it out
A few weeks later it is now changing as well as it ever did - although 4th gear does look a bit worn (one of the problems with a mid drive ebike!)

 

[mickle]

Pop the outer cable out of the frame stops and check for a kink in the inner. Sliding the outer to and fro over the inner will help you locate the problem. Also check to ensure that the cable is routed correctly - under the BB for eg.

 

[Ajax Bay]

Sounds like a new chain with a worn cassette on your commonly used gears or vice versa?

Whatever else, it's not this.
@livpoksoc If you put the 'gravel' wheels back on do these reported symptoms replicate?

 

[livpoksoc]

It's a brand new bike. Covered 60 miles across two wheel sets, so shouldn't be anything worn at inconsistent rates.

I'll pop the gravel wheels on later and see if I get similar.

 

[Teamfixed]

Could be a tight link in the chain? Can happen when a chain is reconnected. Go round each link checking, if you find one, give the chain a very gentle "flex" across itself where the tight link is.

 

[bikingdad90]

Whatever else, it's not this.
@livpoksoc If you put the 'gravel' wheels back on do these reported symptoms replicate?

It's a brand new bike. Covered 60 miles across two wheel sets, so shouldn't be anything worn at inconsistent rates.

I'll pop the gravel wheels on later and see if I get similar.

As it’s a new bike (which wasn’t clear from the OP) with 60miles on it then @Ajax Bay is correct, very unlikely to be worn parts.

 

[T4tomo]

Given its virtually brand new, I'm thinking slightly misaligned mech hanger - could easily have been knocked when shipped.

with matching cassette and discs, swapping wheels over should not bother the indexing or brake alignment at all (I do this on my gravel bike) particularly if it has thru axles, which pretty much every gravel bike does now.,

 

[livpoksoc]

Given its virtually brand new, I'm thinking slightly misaligned mech hanger - could easily have been knocked when shipped.

with matching cassette and discs, swapping wheels over should not bother the indexing or brake alignment at all (I do this on my gravel bike) particularly if it has thru axles, which pretty much every gravel bike does now.,

It's subtle adjustments as the wheelsets are different - stock for Gravel, Hunt for Road. The discs are also not matching - both Shimano, but the bike came with one style, the extras were the ice-tech ones. Same size, but I just take half a turn off the mount bolts, subtly move and tighten.

I wonder if this could be the KMC missing link. It was a b*****d to get back on, in the end I ordered their reconnecting tool to aid, but wonder if needs some additional TLC to free it up.

 

[bikingdad90]

If it the quick link, the tell tail sign would be the chattering appearing at the same point on each revolution.

 

[T4tomo]

I wonder if this could be the KMC missing link. It was a b*****d to get back on, in the end I ordered their reconnecting tool to aid, but wonder if needs some additional TLC to free it up.

possibly - did you break the chain at the split link and reassemble (not sure why you would on a new bike) but they don't recommend this for 11 spd links, although I know people do. easy to check whether it pivoting freely though, or only skipping when the KMC link is on the cassette.

Just a thought if you have had the chain off, have you threaded it back correctly through the rear derailleur, its easy to get it wrong side of the little guide tab, which would make it chattery..

 

[ColinJ]

Just a thought if you have had the chain off, have you threaded it back correctly through the rear derailleur, its easy to get it wrong side of the little guide tab, which would make it chattery..

I did that once. It took me 45 minutes to work out what was going on! (I was in a hurry to meet someone and didn't want to be late.)

 

[livpoksoc]

possibly - did you break the chain at the split link and reassemble (not sure why you would on a new bike) but they don't recommend this for 11 spd links, although I know people do. easy to check whether it pivoting freely though, or only skipping when the KMC link is on the cassette.

Just a thought if you have had the chain off, have you threaded it back correctly through the rear derailleur, its easy to get it wrong side of the little guide tab, which would make it chattery..

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.

On the guide, I've made that mistake before on my old bike. Once bitten...not this time.