We put the new Shimano Dura-Ace R9100 electronic groupset head to head with SRAM Red eTap
With the launch of Dura-Ace R9100, Shimano has launched a new salvo in the battle of top-end electronic groupsets against SRAM Red eTap and Campagnolo EPS.
If you’re buying a new bike with electronic shifting in the next year, the likelihood is that it will be fitted with with either SRAM eTap or Shimano Di2, so we’ve put them head to head to see how they compare.
Ease of setup
Compared to mechanical groupsets, SRAM eTap and Di2 are both easy to set up. Although both still have high and low limit screws on the derailleurs, all of the rest of the set up is done using buttons on the derailleurs and the shifters, which makes micro-adjusting the shifting a particular doddle.
SRAM eTap is the easier of the two systems to set up initially, and should be well within the capabilities of anyone with a decent set of Allen keys and the ability to read an instruction manual.
Watch: how to install SRAM Red eTap
Our step-by-step installation guide will give you a full run-through of how to fit SRAM Red eTap, but it really is as simple as bolting on the derailleurs and lining up the gears using the function buttons on the shifters and the limit screws on the derailleurs.
Shimano Di2 has a slightly more complicated setup process. Bolting on and adjusting the derailleurs is done through a broadly similar process, however you also have to deal with the routing of the cables to connect the derailleurs, shifters, battery and junction box.
If there’s one area where Di2 wins outright, it’s on battery life. The latest iteration of Shimano Dura-Ace Di2 should be good for 2000km on a full charge, which might be only two weeks riding if you’re making your way around France in July, but should be a good couple of months for the rest of us.
Power for Di2 is provided by a single central battery which is usually located inside the frame. This is then recharged through a plug in the junction box, with charging only taking a few hours. The junction box also includes a light which gives an indication of the battery life when you hold down a shifter button for a couple of seconds.
Watch: buyer’s guide to road bike groupsets
SRAM eTap is powered in a different way, with the derailleurs having separate rechargeable batteries, while the shifters each have a CR2032 coin cell battery. Battery life is then indicated by a light on each component, which changes colour depending on how much juice you’ve got left.
Although the SRAM shifters will last up to two years on a single battery, the derailleurs have a stated battery life of 60 hours or 1,000km, so roughly half that of Shimano Di2.
However, when the batteries do need charging, the process is nice and easy, with SRAM Red eTap coming with a charging dock which simply needs to be plugged into the mains, into which you put a removable battery from the derailleur which will be fully charged in an hour.
Dura-Ace R9100 comes with redesigned front and rear mechs with the latter now able to handle cassettes of up to 30 teeth. It’s telling that when Shimano explained to us why they do not see the need to update Dura-Ace to wireless shifting, they said that the feedback from the pros was that the shifting on Shimano Dura-Ace Di2 was so good that there was simply no point messing with it.
The new Shadow rear derailleur architecture, which is transferred over from Shimano’s MTB groupsets, ups the game still further on shifting quality, with the mech body positioned directly below the cassette rather than to its right for more precise shifting.
Where the new Di2, and indeed all electronic shifting systems (including eTap), stand out is with the front derailleur shifting. Having an electronic motor in the front derailleur gives a hell of a lot more power than you get with mechanical systems, which is a particularly good thing if you have small hands and struggle to properly reach the shifting levers.
Watch: SRAM Red eTap review
While mechanical systems can require a decent amount of force to be applied to the lever, particularly when shifting from the small ring to the big ring, with an electronic system you just need to give a quick press of a button applied with no more force than if you were shifting from the 12 to the 11 with the rear derailleur.
So if Di2 and eTap can’t be separated at the front, it’s at the rear derailleur where Di2 really sets itself apart.
As you’d expect, the shifting is crisp and precise, but also seriously fast, so you can always be confident that you’ll quickly be able to find the right gear when it’s needed to respond to an unexpected attack.
With Dura-Ace R9100, Shimano allows you to fine-tune your shifting parameters without needing to plug into a laptop. Its new E-Tube phone/tablet app connects wirelessly to the groupset’s “brain”, allowing you to program shifting parameters or port these over complete from another bike without needing to hook up a computer, as was the case with its older version.
Unfortunately, SRAM Red eTap can’t quite match Di2 at the rear derailleur. The shifts are just as accurate, but just a little bit on the sluggish side. Ok, to call them slow would be pushing it, as they’re still completed within half a second or so, but if it’s race performance that you’re after then you might hope for a little more.
SRAM has acknowledged this slow shift speed, saying that the decision was made to slow down the shifting speed in an effort to prolong battery life, but perhaps it could offer a firmware update to enable faster shifting for racers who would be prepared to sacrifice decent battery life.
However SRAM eTap does claw back some ground with its intuitive shifting system. While the hand movements used to shift on Di2 are the same as with mechanical Shimano systems, SRAM has taken a completely new approach with eTap, using the right lever to shift up at the back, the left lever to shift down, and both together to change the front derailleur.
This can take a bit of getting used to, but is dead easy to use once you get the hang of it, even when wearing bulky winter gloves. The SRAM eTap shifters also give a bit more of a click when you’re shifting, meaning that you can always be sure that the button has been pressed and the signal has got through.
Dura-Ace R9100 now allows you to set up the shifters to work in a Synchronised Shifting mode.
A single shifter can be used to control up and down shifting, with the system determining when a gear change requires a shift of the chainrings as well as the cassette sprockets. There’s also a semi-synchronised mode in which the rear mech is automatically trimmed in response to the rider shifting chainrings, so that there’s not a large change in ratios.
This all goes some way to closing the gap with SRAM’s system.
With all of the non-electronic parts (i.e. the chainset, cassette, chain, brake calipers, and bottom bracket) being taken from SRAM Red, the world’s lightest groupset, it’s no surprise that SRAM Red eTap is more than 150g lighter than Shimano Dura-Ace Di2. In fact it’s the first electronic groupset to duck in below the 2kg barrier.
Watch: which climbs faster – a lightweight bike or an aero bike
However if you add up just the comparable electronic parts, then SRAM Red eTap totals 658g while Shimano Dura-Ace Di2 comes in 36g lighter. But on top of that you of course need cables and cable housing (and frame ports) for Dura-Ace but not for eTap.
|SRAM Red eTap||Shimano Dura-Ace Di2|
|Chainset||557g||609 – 621g (dependent on rings)|
Shimano hasn’t yet announced UK prices for Dura-Ace R9100, but its older groupset was bettered by SRAM Red eTap and the latter doesn’t require cabling or junction boxes either. It will be interesting to see where this new version of its top end groupset is positioned by Shimano.
This page was updated on June 30, 2016 with the release of the new Shimano Dura-Ace.