Ultegra r/mech problem

[Dangermouse]

I changed the rear mech to Ultegra a few weeks ago 6700 and ever since it always sounds as if it is wanting to change gear, only very lightly but I can hear it, it is running on the Madone with 10 speed cassette and KMC X10 chain so really cannot see there being a compatibility issue, the mech has been indexed and indexed again so it is or seems perfect when going through the gears off the ground, no cables are caught and every thing seems fine, but it has this slight niggle which is annoying me............oh and the missus says the bike was knocked over by the dog weeks ago when it still had the 105 mech on, I have had a look at the hanger and even that seems fine as the bike had a soft landing, any ideas as this really is annoying.

 

[Rohloff_Brompton_Rider]

Check the mech hanger, there are you tube videos - but basically look down the length of the bike from the rear (easier with the chain off) and check that the jockey wheels are in line with the cassette. A ruler is very helpful, put it between the cassette sprockets in the middle and ensure it's pulled flat. Then eyeball or measure each jockey wheel centre they should be the same distance from the rulers edge.

 

[User33236]

Check the mech hanger

+1 my Mrs had the same problem with her Lapierre recently and the hanger turned out to be the issue.

 

[Dangermouse]

I have just re indexed it and reseated the cable, and it seems fine............for now, I will give it a test ride later and if it still makes the noise under load I will get a new hanger ordered, I have given it a good look over and it all does seem to be perfectly straight, but as you say, with hangers you cant really tell.

Cheers for the advice fellas

 

[Rohloff_Brompton_Rider]

A new hanger? It's really easy to sort out your existing one.

 

[Dangermouse]

A new hanger? It's really easy to sort out your existing one.

How, do they bend easily back into place?

 

[Dangermouse]

I will get a pic and pop it on here, let you see if it has bent

 

[User33236]

Mrs SG went to the LBS and they straightened it for her in about 10 minutes.

 

[raleighnut]

Check the mech hanger, there are you tube videos - but basically look down the length of the bike from the rear (easier with the chain off) and check that the jockey wheels are in line with the cassette. A ruler is very helpful, put it between the cassette sprockets in the middle and ensure it's pulled flat. Then eyeball or measure each jockey wheel centre they should be the same distance from the rulers edge.

Now this one sounds like it may be the hanger. LBS 10 mins with a hanger tool should either fix or eliminate that.

 

[screenman]

I wrote about the rear mech alignment tool a while back and was shot down in flames by a few string and hammer guys, it really is a worth while investment, even without a knock the hanger can go out of alignment over time. They also only take a very slight sideways knock like the one you describe to move them a bit, if you buy a tool you will be suprised how little effort is needed to align them.

 

[Dangermouse]

Looking at this, it does look like it has twisted

 

[Cuchilo]

My grandad used to blame the dog when he passed wind

 

[Dangermouse]

 

[Dangermouse]

Just waiting for LBS to open and give them a call, for a quote, it has to be cheaper than 15 quid as that's how much a new hanger costs

 

[Dangermouse]

Well we rode up to our LBS and its closed today............but the good news is, after the cable was refitted and the gears indexed AGAIN the problem has gone, absolutely no noise from any of the 20 gears, climbing hills or on the flat.............problem solved