“I have to say that I love the new Shimano Di2 Ultegra 8100 12-speed group set. It’s my first time riding Di2 and now I know what the buzz about electronic shifting is all about. The shifting is fast ...

The nutshell version is this: I’ve ridden the new Dura-Ace 12-speed Di2 also, and Shimano’s Ultegra group performs every bit as well, but for a lot less money and only a few extra grams.

The new Ultegra RX derailleur comes in mechanical RD-RX800-GS and Di2 RD-RX805-GS models. Both use the company’s Shadow technology and have the same low-profile appearance as the R8000 and R8050 ...