retrobiker273891
Retro Guru
Obviously I am talking about friction not indexing on thumb shifters.indexing on thumbies works exactly the same as any other shifter - the indexing relies on an accurate cable pull for each click to move the RD the right amount. there is no extra latitude you magically get with thumbies
smaller number of sprockets tends to be less finicky than higher though (ie a 7 speed system will be easier than an 11 speed as the more gears that are stuffed in there the more accurate the pull needs to be)