Stumped, which is a first.
Dura Ace STI’s 10 speed (2008ish)
105 rear mech RD5701.
New inner outers
New cassette
Front works fine.
Can’t get either good up or down shifting, can’t even get good shifting even by sacrificing one or the other.
Tried alternate cable clamping.
Tried all my own wheels.
The levers are operating the rear mech, but it seems load more pull is required.
I don’t know the history of the bike, its a resprayed Litespeed. Mish mash parts, can’t tell if all is straight.
The only thing I can’t try is s longer chain.
?

Are you 100% sure the shifters are 10 speed? 2008 is pretty early for 10 speed. Alternatively, is the cable seated correctly in the shifter? I know this has been a struggle for me in the past.

Just had the same with a drivetrain rebuild on my old 8 speed, that was due to clamping the cable on the wrong side of the bolt.

Correct sized inner and outer combo?

some dura-ace stuff only works with other dura-ace !!!

Chain age?

therevokid – Member
some dura-ace stuff only works with other dura-ace !!!

There is a table somewhere as it isn’t straight forward that ten speed works with ten speed.

From here

http://www.celebrazio.net/bicycling/shimano/2009_compatibility.html

Deffo gear inners outers. Sorry chain is new as well. I think post 97 all 10…10 works.

Have you checked the mech hanger?, that was one of the first things we check on a bike when they come into the shop

Are you 100% sure the shifters are 10 speed? 2008 is pretty early for 10 speed.

No it’s not, Dura Ace went 10 speed with 7800 in 2004.

some dura-ace stuff only works with other dura-ace !!!

Rubbish! They tweaked front mech ratios on 7900/5700/6700, but rear didn’t change, and they’re close enough as to be cross compatible anyway frankly! As shown by the link above.

Hanger ok?

Last cable outer has too much friction. Loosen cable clamp, lube cable and refasten and set.

Frustrating one to track down. Often caused by a very wet ride – ride London in my case.

New cables? Unlikely.

Are the mech pivots very tight? Including the b-axle assembly?

I’d go for bent mech hanger too.

All looks well, set up fine, no friction
Its been suggested that what appear to be el cheapo cables could be to blame, crap cables can be crap. So possibly a cheap first fix.

Bent hanger? Had these symptoms on my at up a few months back and that was the culprit.

+1 for bent hanger, spent a whole night pulling my hair out trying to get my 105 10 speed setup working. Borrowed a park hanger alligmment tool and found it was miles out even though it looked fine.

Straightened the hanger and gears worked straight away

If the limits are fine, but you can’t get consistent indexing within the cluster… bent hanger! I check this within the first minute of any rear mech related repair that comes in.

Well, I had exactly the same symptoms and suspected a bent hanger – measured with the correct tool, it was dead on. A new £1.50 cable outer cured the shifting immediately – one of the ferules had a kink in it and this caused the increased friction and poor shifting.

I’ll bet it is this, after all it indexes up OR down, but won’t shift both consistently.

More gears = more fussy shifting.

Cheap cables are often the cause – I’ve seen barely used Jagwire need replaced on 10s, I dread to think what 11s road will bring. Happily I’m on 8 and 9 on my own bikes.

And don’t even ask my thoughts on Di2 routing.

OP you tried different wheels? Seriously?