Sram / Shimano

[BogusOne]

Ok so i know that SRAM works on a 1:1 ratio and Shimano on 2:1, but if the actual indexing of the gears are in the shifters and not the deraileurs then why wouldnt say for instace,  SRAM X-0 twisties work with an XT RD?

 

Please give your opinions

 

[rad006]

No it will work with a XT FD not RD

[BogusOne]

 

No it will work with a XT FD not RD

 

But why do you say it wont work with the RD? Surely if it will work with the FD it should in theory work with the RD. Remember the indexing is in the shifter and not the deraileur.

 

[rad006]

No as your front derailer on both shifters are 1:1 only 2:1 on RD

[BogusOne]

 

No as your front derailer on both shifters are 1:1 only 2:1 on RD

 

Maybe im stupid but that still doesnt answer my question 

 

[rad006]

Yes it does.... Its simple the rear shifters work differently to the front shifters which work the same. Make sense?

[BogusOne]

yeah i know what you mean Rad, guess i will just have to get a set of X-O twisters and do the exercise and see for myself if it will or will not work.

[Johan Bornman]

The mechanical advantage lies in the lever at the cable anchor bolt on the derailer. A Shimano derailer is designed so that X-distance of cable travel will produce 1/2 X distance of derailer travel. Sram is X to X.

Therefore, it is like you say, not the indexing that sits there, but the mechanical advantage or travel ratio if you want.

 

For instance, if you install the cable on the wrong side of the Shimano der anchor bolt, the leverage is changed and the gears won't shift properly.

 

Does that help?

 

[downhilldemon]

i think its a question of leverage - the rear derailers move a different amount accross for the same amount of cable pulled by the shifter

[stewie911]

I didn't even know about the ratio's, but from this thread it would seem that if you use sram shifters with shimano rd, then for each sram shift/twist the rd will only move half the distance.

So that for example with a 10sp sram shifter, you will only be able to move between 5 gears.

 

Am I right?