OK. Sram bizarre 10spd groupsets help needed #Mk2

[Carge]

Re: Re:

of course not. 9 speed shimano is 1:2, 10 speed is 1:1 (approximately) so it was never going to work properly.

Apart from that not making any sense - who mentioned Shimano??
I was referring to SRAM X0 - if you'd read the thread - you'd know that.

 

[mattr]

Re: Re:

Wadsy is pretty darn good when it comes to setting up mechs etc...
But he (we) got no joy from a 9spd shifter and a 10spd mech.

of course not. 9 speed shimano is 1:2, 10 speed is 1:1 (approximately) so it was never going to work properly.

Sorry, thought we'd moved onto shimano by that point.

But on the other hand SRAM actuation ratios also vary from 9 to 10 speed. (Either side of 1:1 IIRC)

And it makes perfect sense, if you understand the differences in actuation ratios.

 

[mattr]

And for further reference, here is a useful link to all things actuation ratio.

http://blog.artscyclery.com/science-beh ... atibility/

 

[dyna-ti]

Re: Re:

And it makes perfect sense, if you understand the differences in actuation ratios.

Now T.ow Thats enough of that Bloody engineering questions. I reckon the shipyards were full of such squabbles

But heres the thing matty dear
Place a board under your bike drivetrain with a felt tip pen sellotaped the the lower half of the cage.
Run through the gears and the mech will follow an arc, which the felt tip will draw on the board.
Now swop the 10 spd for the 9. Same 10spd cassette/chain, only the mechs different
Now will the drawn line follow the same arc ?
If it follows the same arc then the swing is the same, as is where the chain gets deposited.

I could point out that once the chain is on the block any settling will be done by itself, afterall, the front ring and rear cog is in alignment, so the chain will too. The rear mech is only there to deposit it. A lower guide pulley(what are these jockey wheels ?? you all refer to ) has to have some play, that would allow a pick up and deposit and then running with it a bit of leeway.

Its an interesting subject but i think too prone to company SELL THE LATEST THING mentality.

 

[stevet1]

Now will the drawn line follow the same arc ?

No, not if the actuation ratio is different. Lets say the shifter moves the cable 5mm. for each shift. 5mm in cable movement will move a 9 speed and 10 speed rear mech by a different amount. In the extreme example of moving from 2:1 to 1:1 if you keep the shifters the same then each shift will move the 10 speed rear mech by half the distance it needs.

 

[dyna-ti]

An interesting thread here
This is what i love about forums. a niggle, a flummoxing and off we go
http://www.pinkbike.com/forum/listcomme ... did=148662

Best stuff is the problem solving. A great sense of satisfaction

 

[mattr]

Re: Re:

And it makes perfect sense, if you understand the differences in actuation ratios.

Now will the drawn line follow the same arc ?
If it follows the same arc then the swing is the same, as is where the chain gets deposited.

same arc, different motion per click. As per stevet1s post.

Its an interesting subject but i think too prone to company SELL THE LATEST THING mentality.

a lot of it is to sell more kit, make old stuff incompatible. BUT the newer mechs and shifters should also be far more tolerant to dirt and cable settling.

In reality it doesn't make *that* much difference.