Need to know
Find out more about this latest version of the groupset, plus the bikes that are showcasing it in this test…
SHIMANO’S LATEST VERSION of Ultegra Di2 is exceptional. We’ve been testing the 12-speed electonic groupset for nearly a year now and think it’s Shimano’s best option for real-world riders. Not only is the shifting superb, but it hasn’t required adjustment. As for the braking, this has improved over previous generations; and now, thanks to its built-in wireless communication, you can connect it to a head unit, and Shimano’s phone app, in an instant (this means you can use your hood-top buttons for scrolling through bike-computer menus, display on your screen what gear you’re in or how much battery power you have left, and much more). The semi-wireless design means your bike will look cleaner too, with no extraneous cables to worry about. That makes it a great option for aero-optimised road bikes and race bikes alike.
01 The classic
Our first pick of this Ultegra Di2 bike crop is the legendary Giant TCR, now in its ninth generation since its racing debut in 1997.
The latest version follows the same compact frame shape as the original, but it boasts a lightweight, advanced carbon fibre frame and fork that have been aero optimised using what Giant calls a ‘truncated ellipse’ profile for the tube shapes. Giant claims this is a step on from Kamm-tail-like shapes, with a more rounded take on the truncated air foil for lower drag across a wider range of yaw angles (the angle created from the natural wind plus the headwind you create when riding).
02 The Spanish speedster
Spain’s BH (Beistegui Hermanos) has been building bikes in Europe for over 100 years. It’s always had a reputation for building lightweight bikes to take on the steep slopes of the Spanish Pyrenees and Sierra Nevada. The RS1, however, is the brand’s take on a performance aero road bike. With its resistance-beating Kamm-tail frame tube shapes and the super-slick, fully integrated design of its monocoque frame and fork, the RS1 looks every inch the raceready speedster.
03 Dare to be different
British titanium and steel specialist Reilly has taken the classic titanium road bike and brought it bang up to date with the Fusion. At the heart of the Fusion is its combination of Kamm-tail tubes made from 3AL/2.5v titanium and investment-cast 6Al-4V titanium junctions, including the aeroshaped headtube, seat-tube junction and bottom bracket shell. It also uses hollow, investment-cast dropouts. The icing on the cake is the beautifully seamless welding, which helps create a unique titanium bike.
● Warren has been testing bikes long enough to have experienced every iteration of Shimano’s Di2 technology. Back in 2009, Shimano launched the original Dura-Ace Di2 (10 speed, rim brakes). You had to tape the external battery and wiring to the downtube using a heat gun and heat shrink them to protect the connections. Thankfully things have moved on since then…