MTB Trigger Shifter - Actuation Ratio

[jethro10]

Can someone explain what this actuation ratio is?

Been looking at shifters and a lot are 1:1 ratio. The Sram Attack levers, and no doubt others are 2:1 just noticed!
Does this mean, and it would make sense, that you move it twice as far, for a given gear movement, but this makes it twice as easy to push?

It's just my wife struggles big time with strength to move the levers, especially moving up in gear size on the front, and I wonder if this is an option.
Don't know why she suffers, you would thing all the housework and gardening I give her, would strengthen her up a bit

EDIT: Just looking more, perhaps it's a brand thing, they seem to be designed to work with shimano equipment. So totally lost now
Ta
Jeff

 

[spence]

SRAM Attack (and Rocket if you can find them) are designed to work with Shimano rear mechs that are 2:1. SRAM X7, X0 etc will only work with SRAM rear mechs 1:1 pull.

If your wife is finding the shifer hard/stiff to use replace the cable, works wonders.

 

[jethro10]

Ok Thanks,
so are shimano all 2:1 and Xram all 1:1 so you never mix brand?

Out of curiosity, are rear cassettes all interchangeable or are they matched to the rear changer?

and front cogs to front changer.

ta
Jeff

 

[P.H]

What spence said plus-
Shimano and SRAM cassettes and chains are interchangable.
SRAM make both 2:1 and 1:1, just remember if it's got a name you can mix and match and if it's called a number it's SRAM only.
The SRAM 1:1 is a bit lighter, the main advantage is it's more tolerent to being slightly out of tune.

 

[jethro10]

Ok, gotcha thanks.

Jeff