Ultegra Di2 and 105 Di2 are also electronic, before you move into Shimano's mechanical groupsets. These go from 105, which is 12-speed, all the way down to Claris, which has eight speeds.

Some readers will likely note Shimano already has clutch mountain bike derailleurs ... the first to bring you official details on the derailleur as well as the new 105 groupset. We take a look at the ...