Head-wall-repeat ... what am I missing here?!

First up, apologies it's not a proper retro, but I cannot seem to get Kiran's gears shifting properly at both top and bottom of the cassette - it's either one or the other and then it runs out as if it's pulling/releasing too much cable per shift :?

Set up is:
m770 shifters
m770 rear mech (tried two with various jockeys - OEM, Tacx, KCNC)
Various cassettes including m770, m760, m970 and SRAM XO
Few chains, new and used, KMC 9SL, SRAM, Shimano XTR
Swapped from ordinary cables to i-Link, no change
Two OEM mech hangers and a new BETD

The only thing I haven't swapped (yet) is the shifters themselves, nothing else has made any difference. It's very much like the time I mounted a gear cable the wrong side of the clamp bolt (some road mechs gave you two options to work with both 7 and 8 speed without changing shifters).

Am I missing something? The frame's ally so shouldn't be bent (although I am checking now)!

Interesting. Only thing I can think of would be to check the limit screws and make sure I was using compatible gear, ie 7 speed shifters and cassette, not 7sp shift and 8 speed cassette etc. Other than that, I would be curious to hear the solution to this.

Shifter missing a 'click'?

sticky cables?

Kink in the cable?

sticky rear mech (almost impossible to detect)?

Always use Shimano jockey wheels for proper shifting btw.

Whatleymeister":1sjj32ep said:

Interesting. Only thing I can think of would be to check the limit screws and make sure I was using compatible gear, ie 7 speed shifters and cassette, not 7sp shift and 8 speed cassette etc. Other than that, I would be curious to hear the solution to this.

Shifter missing a 'click'?

Click to expand...

That is the phenomena for sure, but it's all matching m770 9sp (shh!).

double check your cable clamping as above. that will ruin it.

legrandefromage":1mjzeqbi said:

sticky cables?

Kink in the cable?

sticky rear mech (almost impossible to detect)?

Always use Shimano jockey wheels for proper shifting btw.

Click to expand...

Changed mechs and fitted new cables and outers. You're suggesting the mech isn't pulling strongly enough due to stiction somewhere? That makes sense to me too but I haven't managed to track it down :?

Might fit a bigger rear loop or a rollermajig this afternoon....

elPedro666":1oyzkeci said:

Whatleymeister":1oyzkeci said:

Interesting. Only thing I can think of would be to check the limit screws and make sure I was using compatible gear, ie 7 speed shifters and cassette, not 7sp shift and 8 speed cassette etc. Other than that, I would be curious to hear the solution to this.

Shifter missing a 'click'?

Click to expand...

That is the phenomena for sure, but it's all matching m770 9sp (shh!).

Click to expand...

Don't worry mate. Between you and me, I am running 9sp too...
The purists will see us burn if it ever gets out!

Yeah what the big cheese said plus:

Check chain alignment
Is the bottom bracket axel the right lengh to give a good chain line
is the hanger bent (or nto tight if its replacable)
Is the rear axel bent affecting alignment

cheers
pete

That's a Shadow type rear mech, right? The cable goes "in front" of the pinch bolt as you look at it from the drive side. Ummmm - check that the last loop of outer is long enough to allow free movement, but not too long. All the parts you're using should be compatible, so it's most likely an excess friction/routing type issue. Good luck!

weird, but i had a similar problem with my M770 transmission set, it wasnt shifting to the last gear (smallest cog on rear cassette).
the shifter was mega stiff toward the end of the shifting too.

i opened up the shifter and found a long spring wedged in it. removed it and the problem was solved.
Have no idea why the spring was there/how it was located. but it works fine now.
when i first had the problem i swapped it for a deore shifter (9spd) and that worked fine:

like this:



here is my thread about the problem i had, not sure if this will help at all:

http://www.retrobike.co.uk/forum/viewto ... highlight=