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 ...

In this case, Shimano went off book with their DI2 groupset, leaving [kwakeham] with a reverse engineering job on his hands. [kwakeham] gives us a great example of how to approach reverse engineering.

The Selle Italia SLR Boost Superflow saddle is a treat when you’re on it too, while the shifting comes from Shimano’s Ultegra Di2 groupset, and that as it turns out is one of the highlights here.

All specs of the Xelius are fitted with Shimano electronic groupsets, ranging from 105 Di2 up to Dura-Ace ... steps up to a semi-compact Shimano Ultegra groupset with the same alloy wheels.