Basic Guide To Shifter Compatibility
Shift levers and brake/shift levers are arguably the most important contact point between rider and bike. Miss a shift in the middle of a steep mountain bike climb, and you’re likely to lose momentum and have to get off and push. Do the same during the climax of a road race, and instead of sprinting for victory, you’ll be pack fodder.
To avoid these undesirable outcomes, it’s critical that your bike is properly tuned and that all shift mechanisms are compatible, because shift levers and derailleurs work together to shift gears. In general, avoid mixing shifter and derailleur brands unless the manufacturer specifically states that the combination you are considering is compatible. Here are some other basic rules specific to Shimano shift levers:
Road Front Shifters: Shimano Tiagra, 105 and Ultegra front shifters are compatible with double and triple chainring configurations, but not with mountain front derailleurs. Dura Ace shifters are either double or triple specific.
Mountain Front Shifters: Compatible with triple chainring configurations, but not with road front derailleurs.
Rear Shifters: The shifter must match the number of cogs on the cassette. Road and mountain shifters work with both road and mountain derailleurs.
Shift/Brake Levers: Combined shift and brake levers are installed on almost all road bikes and about half of all mountain bikes.
Road Brake/Shift Levers: Work with cable operated brakes, and are only compatible with caliper and cantilever brakes.
Mountain Brake/Shift Levers: Cable models compatible with v-brakes or mechanical disk brakes, and mixing manufacturers is okay. However, you cannot mix-match brake/shift levers for hydraulic disk brakes.