Miss thumb shifters? Converting a drop bar bike to flat bars? These easily transform bar end (aka barcon or TT) shifters into thumb shifters. The shifters are not included, but are readily available in 8 through 11-speed versions, and many have an option for friction-shifting.
Thumbies bring back the thumb shifting of old, and we think it makes shifting more precise and smoother. These feel much better in our opinion than trigger or twist shifters.
Thumbies have a hinged clamp for an easy installation and fit mountain bike handlebars with a diameter of 22.2mm. The clamp is raised up to give clearance for hydraulic brake levers.
They have a shifter mounting boss that fits Shimano bar end shifters and most Shimano downtube shifters.