SRAM 9 and 10 speed – what's the problem?

I keep reading that SRAM 10 speed rear mechs will not work with 9 speed shifters – Does any one know what the reason is?

It doesnt matter what the reason is, they just wont work

They need different cable pull basically

Clubber – Yet both 9 speed and 10 speed talk about 1:1 cable actuation ratios? So, as the amount of cable pulled is decided by the shifter and not the mech why doesn’t it work?

David – do you still believe in the tooth fairy?

The only person I know who has tried (to be fair, the other way around – putting a 9spd rear mech into a 10spd system because he knackered the original and it was lying around) said it worked fine. As well as the original. Both 9spd and 10spd blurb on the SRAM site talks about 1:1 as you say.

I wonder if the confusion comes from Shimano being different and an implied assumption that sram is the same?

caveat – not done the fettling myself but no reason to disbelieve and seen it running with my own eyes.

Could the primary issue be Jockeys?

9Speed chain/jockey wheels being marginally wider than 10? Hence you may be able to bodge 10 speed chain through the wider spaced 9 speed cage, but not vice versa?

Well SRAM are selling 2011 rear mechs in 9 and 10 speed flavours.

IIRC, 1:1 isn’t actually 1:1 – it’s more like 1:1ish so while they’re both ‘1:1’ the ‘ish’ is different. Give it a go…

1:1 is all well and good but the movement of the mech is not decided by the cable pull. It’s decided by the pivots of the mech so a 1mm move of the cable could have a much greater or smaller effect on the mech depending on the distance between linkages.

Yeah, it doesn’t work at all. Just went through it with an X9 10 speed mech and X0 9 speed gripshift. You basically get almost 9 gears of travel at the mech in 8 clicks at the shifter.
Switched out the mech for a 9 speed X9 and it works perfectly.
They tweaked the cable pull for 10 speed, but didn’t tell anybody. The culprit is “Exact Actuation”, it seems that any mech that features that, whatever it is, only works on 10 speed.

PAul

Just come across this thread whilst wondering how gripshift and 10-speed cassettes can be made to work together.

Did Paulpalf get 10 speeds out of the rear cassette using a 9-speed rear mech and gripshift? Surely the 9-speed gripshift has 9 stops in the ratchet which won’t correspond to those needed by a 10-speed cassette?

http://luckynino.blogspot.com/2009/03/10s-grip-shifter-from-92g.html sells 10-speed gripshift. Has anyone tried it yet?

Well worth looking at his site for the footage http://luckynino.blogspot.com/2009/03/extreme-alpine-biking-on-ht.html of Lucas Stoekli and Thomas Frischknecht (mostly) riding up and back down the 4,165m Breithorn! 🙄

It’s logical if you think about it. The 9 and 10 speed cassette widths are exactly the same, but the shifter/mech has to put in 8 stops for a 9 speed and 9 stops for a 10 speed. So forget the 1:1 whatever that means. If the cassette width is X, each click on a 9 speed moves the mech X/8 mm, and 10 speed X/9 mm

I think the confusion is coming from using 9 speed Shimano mechs on 8 speed stuff. The spacing is exactly the same between the cassette rings so that’s why that works. On a 9 speed hub you have to use a spacer as the cassettes are obviously different widths but on a 9 and 10 speed the cassettes and the same width so it’s obvious the spacing between the caassette rings is different. So when you shift a 9 speed SRAM shfter it will mover the cbale slightly more. The best solution is simple – don’t mix them!