trouble setting up new Ultegra rear shifter

[Chris Long]

Hi, I bought a new Colnago CRS frame recently and transferred my Ultegra groupset. New brakes, new rear mech, new front mech, year old crank, new chain

But I am using my old 105 shifters as I have never upgraded those.

Polished and cleaned everything so they were spotless and put them on.

First ride out after setting up gears are moving well, odd little noise so I adjusted.

Since then I just haven't been able to get them smooth. I've even started again.

New cables, new outer cables, etc

could it be the 105 shifters?

Chris

 

[Tenacious Sloth]

Have you checked the alignment of the rear mech with a hanger alignment tool?

Graham

 

[Chris Long]

i haven't, but its a new hanger, new frame, new mech?

 

[Tenacious Sloth]

I run 105 shifters with Ultegra mechs with no problems, so I wouldnt expect them to be causing problems unless defective.

I’ve heard stories of rear hangers being out of alignment on brand new bikes being assembled in bike shops, so I wouldn’t rule that out as a possibility.

Also, I would imagine that incorrect chain line could cause problems, I.e. chainset too far out or in, but have no personal experience of that or how to set it up correctly.

What exactly is the problem? Is it noisy chain operation or problems with shifting?

Graham

 

[Chris Long]

The smallest three cogs shift fine. Its the middle. Of the cassette that is the issue. Changing up OK, changing down, just can't get it smooth.

I've just checked the hanger. On one of the allan screw I managed to get a full turn on it which means it has either loosened since I put it together four weeks ago, or I hadn't fully tightened.

If that's the case it could have been slighty out. If re indexed from scratch. Seems smooth but still tricky getting the changes smooth at the top end. I won't now now till I give it another test run.

 

[mikeymustard]

Typical behaviour of a misaligned/bent hanger. Now you've tightened it all up with any luck that will have solved the issue. if not then the alignment's probably still out

 

[gds58]

Might be the ‘B’ screw adjustment. This is the little screw usually towards the back and inside of the rear mech which adjusts how far the top jockey wheel is from the cassette sprockets. It can sometimes be crucial and can make an enourmous difference to the slick operation of the gears.
Worth experimenting with this a bit.

 

[davidphilips]

Silly idea perhaps but check rear wheel is aligned if it is out then same symptoms as a rear mech out of alignment?