Rear Derailluier doesn't shift mid cassette

[antnee]

Well Fitted a new shifting cable to rear derailliuer as sheared and frayed too after having to strip shift lever to remove the nipple end from lever housing, fitted new cable & set up gearing after found that gearing was mishifting First of all wouldn't shift to the largest sprocket then after adjusting the inner shift adjusting screw and corrected that. found gears mishifts mid cassette. So after doing a search on the web I havn't found anything to help me cure this. So am wondering if anybody can help me its a 10 speed Ultegra GS derailluier. Thanks anybody got any Ideas Cheers.

 

[fossyant]

Did you change the outer cable too - if not, do so. Miss-shifts, especially mid gears, point to issues with the cables. Road shifters really need decent cables. Make sure you don't have any debris in the shifter !

 

[Milkfloat]

In memory of @screenman who was correct in this statement 'have you checked derailleur alignment?' I would also suggest looking to make sure you have the routing of the cable into the tension bolt correct.

 

[antnee]

Will Look into both of these suggestions Though having to remove cable end from shift lever mech did close inspection of the lever to make sure no debrie left within and looking at the cable fixing at the the derailliuer end I thought it was correct

Thank you.

 

[T4tomo]

if some of the changes are fine, but it runs like its mid shift between two gears at the other end of the cassette range, the check hanger alignment, but defo eliminate sticky cables first.

 

[Smokin Joe]

Try clamping the cable round the other side of the bolt (Above where you have it in the photo). That does cause the problem you mention.

 

[Once a Wheeler]

In the past, when replacing a frayed cable, I have had a similar problem that seemed incapable of resolution until meticulous inspection revealed a section of a single strand of the old frayed cable had become lodged in the outer casing. It did not prevent the insertion of a new cable nor totally prevent gear changing — it just led to the symptoms you describe. New outer casings will solve the problem or you may be able to chase the fragment out with a length of welding rod, steel wire or a chopped down spoke. Best of luck.

 

[antnee]

Thanks again all.
I tried the cable above the fixxing screw and it didn't sem to make any difference, Though as the most of cable is internal (through the frame) The only parts of the cable that pass through outer cable is the bit beneath the bar tape, then into the frame then the section at the rear to the derailleur. though I feel I must add I didn't think the cable passed through the inturnal section as well as it might. though at the moment after some more fiddling with the adjustment screw it seems to change ok well thats in the work stand, but out on thte road is a different story sometimes which I will have to test tomorrow.

 

[Ajax Bay]

gears mishifts mid cassette.

Observation: Lack of cable tension (chain on smallest sprocket) shown in the image (which won't affect the shifting mid-cassette).
Think you may need to be more precise. Are they OK for the smallest 3 sprockets and the largest 3 sprockets?
What STIs?

 

[T4tomo]

then the section at the rear to the derailleur

that's the bit of outer cable that benefits most from being changed when you change inners as it gets all the wet, gunk etc thrown up off the road at it, so most liable to internal corrosion. Fortunately also the easiest bit to change.

 

[antnee]

Thank you T4tomo. That does make sound sense thinking about it, I must say I always think of the most complex ideas first will get some more cable end nipples and check this out.

 

[Ian H]

What is the 'inner shift adjusting screw'?
If it wouldn't move to the large sprocket I would have adjusted the cable. Similarly for alignment with the other gears. Though,As others have said, the cable may be a bit sticky as well.

 

[T4tomo]

What is the 'inner shift adjusting screw'?

also called a limit screw

 

[Ian H]

also called a limit screw

Which is what I assumed. There's no reason to adjust that after a cable change. It doesn't adjust the shift.

 

[Roseland triker]

I'll go with too much cable tension causing ghost shifting.