Electric Is Here To Stay Shimano’s New Dura-ace Di2 Groupset
Ridersmight have been skeptical, but the arrival of Shimano’s Di2 groupset four years ago raised the bar for bicycle components. Triathletes have the most to gain from this innovative system thanks to the bar end and brake hood shifting, but will also benefit from the improved shift speed and reliability. The new 9070 Di2 group shares cranks and brakes with its mechanical sibling, but the entire group is much lighter than in years past. It’s also much more user-friendly and customizable. It won’t be this year or next, but Shimano’s latest Di2 offering proves that the future is electric. Battery The external battery is the sole component carried over from the original Di2 group. Now, though, there is also an internal battery option that fits inside the seatpost. According to Shimano, when using the internal battery (which holds a charge similar to the external one), the new Di2 group is actually lighter than mechanical Dura-Ace. Rear Derailleur The new rear derailleur is steamlined and looks comparable to its mechanical relative. The 9070 derailleur also has the ability to shift through the entire cassette with a single touch. Crankset The new four- arm spider gives the 9000- series cranks a striking new appearance. By eliminating the fifth arm, and carefully positioning the remaining four, the chainrings are well supported during the power phase ( picture your pedal stroke as working around a clock – this would be between 3 and 9 o’clock), maintaining stiffness that enhances shift quality. The three- dimensional hollow chainrings provide impressive stiffness, which directs all your energy into moving forward, but remain remarkably light. An added bonus of the new arrangements is the ability to swap from a standard ( 52/38, 53/39 or 55/42) to a compact setup ( 50/34 and 52/36) without swapping cranks. Racing a flat fast course like Ironman Arizona? Set a new PB with the 53/39 setup. Racing Muskoka 70.3? Throw on the 50/34 compact to spin your way up the steep grades to a berth at the world championship. Shimano’s new 52/36 option promises to offer the best of both setups for courses like Challenge Penticton and Ironman Mont-Tremblant, with the combination of long uphills and fast descents.