Thumbies allow you to mount bar end shifters on your handlebars to replicate the indexed and friction thumb shifters of decades past. Paul Components Thumbies are the original upright handlebar mount. They easily transform bar end shifters into thumb shifters. These shifters are not included, but are readily available in 8, 9 and 10-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 than ever before. These feel much better in our opinion than trigger or twist shifters. Thumbies have a hinged clamp for an easy installation. Available to fit handlebars with a diameter of 26.0mm. On road bike bars this is the thicker section of the bar where the stem clamps on. The clamps of the 26.0 version are designed to work next to inline brake levers like our Cross Lever. The Shimano version has a shifter mounting boss that fits Shimano bar end shifter and some downtube shifter. When paired with Silver Shifter Adapters, Shimano style Thumbies work with the excellent ratcheting Silver Shifters from Rivendell. These shifters work just like the old Suntour Power Ratchet shifters but better. Thumbies are available in left and right pairs for front and rear shifters, or as single front or rear shifter mounts. A single right Thumbie for a rear shifter works great on a bike with a simple 1x10 drivetrain. Specifications: 26.0mm Shimano fittings Only left thumbies available.