My bike has a Suntour RDER and Suntour power shifters on the down tube. I have to move the lever 30-45 degrees to shift from one cog to another. This happens with both a V-GT and a 1st gen Cyclone GT, whether I'm up- or down-shifting.

A couple of days ago, I rode a bike with Shimano 600 Arabesque shifters and RDER. The seller said the bike used friction not SIS. The shifts required much less lever movement than my bike needs. I think shifting through all 6 cogs required less than 90 degrees of movement.

Is something wrong with my RDERs or shifter?

Thanks in advance.