Originally Posted by HDTVKSS
can somone explain the difference ith 1:1 and 2:1?
With 1:1, the shifter mechanism moves the exact same amount as the derailleur and cable. With Shimano's 2:1, the shifter mechanism moves twice as much to move the cable and derailleur the same amount.
Some say this gives the edge to SRAM with regards to precision shifts.