Gear indexing - front ring

mcstumpy

Hi

I changed wheels and cassette at the weekend and gave the drive train a good clean, degrease and lube. Gears were a bit clicky so I adjusted barrel at rear derailleur until smooth changing. But I only checked the big ring. Gears are fine on that front cog.

But on small ring (50/34) when out yesterday the gears were jumping on occasion, I think whenever under load on a steep hill.

Factor to note in case relevant - this is my flat bar Triban 540 that was recently converted to drop bar, the front derailleur is controlled with a bar end friction shifter. Yesterday was first real spin since that conversion.

So was wondering, should I check and adjust rear derailleur barrel when on front ring until all ok? Is it a front mech adjustment needed? Or something else?

All advice gratefully received, thanks.

mcstumpy

Just to clarify, rear mech controlled via 4600 sti. Ie indexed. Its just front mech that is friction shifted.

arlowood

Did you renew your chain when you fitted the new cassette. Gears jumping is often a symptom of a worn chain running on a new cassette.

My first suggestion would be to check your chain for wear or if the chain is the same age as the old cassette you replaced then buy a new chain

mcstumpy

Thanks. Chain is only 8 months old, done around 400 miles. So should be ok?

mcstumpy

And in case I'm using wrong terminology, by jumping I mean that when pedalling the chain moves up 1 sprocket on the rear cassette.

arlowood

McStumpy wrote:

And in case I'm using wrong terminology, by jumping I mean that when pedalling the chain moves up 1 sprocket on the rear cassette.

To further clarify - "moves up 1 sprocket" Does that mean moving from a smaller to a larger or from a larger to a smaller sprocket?

mcstumpy

Smaller to larger sprocket.

StillGoing

McStumpy wrote:

Smaller to larger sprocket.

Start again by indexing the RD properly. Inner ring (34) and disconnect the cable from the RD. Wind the barrel adjuster in fully and back out 12 turns. Push the RD in so it is under the largest sprocket on the cassette and adjust the L limit screw so the top jockey wheel sits directly under the sprocket. Let the RD back to it's position under the smallest sprocket and adjust the H limit screw so the jockey wheel sits just outside (away from the wheel) being directly under the sprocket.

Ensure the shifter is set to be selecting the highest gear (12/11) and reattach the cable. You don't need to strain on the cable to reattach it. You may need to re-attach the cable a couple of times to get the right tension in it, but fine adjustment can then be made with the barrel adjuster.

mcstumpy

Thanks for that, will do as suggested.

arlowood

McStumpy wrote:

Thanks for that, will do as suggested.

For additional info here is one of the best video's on gear indexing

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

mcstumpy

arlowood wrote:

McStumpy wrote:

Thanks for that, will do as suggested.

For additional info here is one of the best video's on gear indexing

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

Cheers for that

StillGoing

philthy3 wrote:

McStumpy wrote:

Smaller to larger sprocket.

Start again by indexing the RD properly. Inner ring (34) and disconnect the cable from the RD. Wind the barrel adjuster in fully and back out 1 to 2 turns. Push the RD in so it is under the largest sprocket on the cassette and adjust the L limit screw so the top jockey wheel sits directly under the sprocket. Let the RD back to it's position under the smallest sprocket and adjust the H limit screw so the jockey wheel sits just outside (away from the wheel) being directly under the sprocket.

Ensure the shifter is set to be selecting the highest gear (12/11) and reattach the cable. You don't need to strain on the cable to reattach it. You may need to re-attach the cable a couple of times to get the right tension in it, but fine adjustment can then be made with the barrel adjuster.

Predictive text! It should say 1 to 2 turns and not 12.

mcstumpy

Thanks for all the advice, that video especially was excellent. Followed that and now all sorted.