Shimano Ultegrea di2 6870, electric

There's been a feast of groupsets this year and everyone is dining out on introducing 11-speed to their ranges.

If you've been following the sequence of component-related events, it will come as no surprise to hear that Shimano is finally launching the extra sprocket to its Ultegra Di2 electronic groupset, giving it the designation 6870.

In typical trickle-down manner, Ultegra Di2 11-speed gains many of the same features that Dura-Ace 9070 adopted with the advent of 11-speed, albeit using a cheaper bill of materials akin to the mechanical version. Like the Dura-Ace 9070 Di2 STIs, Ultegra 6870 Di2 also gains larger paddle shifters, but like the 6800 they are in aluminium as opposed to the carbon sported by 9000.

With Dura-Ace adopting the same ‘E-tube' wiring earlier this year, the system is now standardised across the Shimano Di2/Alfine ranges, which also means Ultegra now benefits from some of the previous Dura-Ace only features, like the ability to run either the three or five-port junction box.

Three-port or five?

The three-port box allows space for both STIs, sprint button shifters (generally mounted on the inside of the drop bars) or the mounting of a Classics/climbers-style button shifter on the tops à la Sammy Sanchez.

The five, however, has enough ports for the inclusion of the new Ultegra tri-bar shifters, which Shimano says it produced in response to large Ultegra Di2 6770 customer demand. Seeing as the cabling between Ultegra and Dura-Ace is now the same, this will also offer Dura-Ace customers a more affordable option.

The other E-tube standardisation benefit is the ability to use the Dura-Ace internal battery and, with the help of a slight software rejig, the ‘multishift' option (the ability to change multiple gears with one button hold). Interestingly enough, this can also be retro-programed into the 6870 10-speed with a software update.

It's likely that shops with the plug-in diagnostic kit are likely to charge you for the privilege of updating software, but it's worth having a chat about any shifting preferences you may require at the bike-buying negotiation stage.

The one upgrade that Ultegra Di2 gains over Dura-Ace is the choice of two rear mechs: standard short reach for up to a 28t sprocket, and the longer GS to allow for the new 32t sprocket option.

10-speed surplus

The elephant in the room though is the significant number of bikes with Ultegra Di2 10-speed still available. There's no denying that although there was a huge demand from retailers for Ultegra 6770 Di2, customers weren't quite as digitally on board as was originally expected, with some retailers citing performance and quality as reasons for poor sales.

Shimano UK representative Mark Greshon from Madison UK believes that the reason for lack of sales is twofold: "Firstly demand from retailers was 50 per cent more than what Shimano had forecast.

This initially led to supply delays, but Shimano upped production and within six months delivered everyone's orders, so manufacturers ended up with it on several different ranges of bike. The other issue was price. Ultegra Di2 costs about the same as Dura-Ace mechanical, which led to retailers pairing it with as-cheap-as-possible bikes.

Newcomers to the bike market were more reserved about purchasing electronic shifting and more experienced cyclists realised that the frame and wheels were budget. As an OEM seller, Madison got the forecast just about right, and we're seeing a large number of high specced bikes being fitted with Ultegra."

The cost of the new 6780 will still be on a par with Dura-Ace 9000 (mechanical) and retailers have learnt from being over-eager and initial forecasts are lower than those previously made. If you are sold on electronic shifting, it's still significantly more affordable than Dura-Ace 9070 at nearly £3k for the groupset, and going on our past experiences we'll be more than keen to give it a go.


As with all 11-speed groupsets, the addition of the extra sprocket will almost certainly mean you need at least one new wheel. The good news is that there are a few brands out there already equipped to take 11-speed.

If you like your collars matching your cuffs, then you'll be pleased to know that all the carbon/alloy clinchers of the WH-RS81 C50, C35 and C24 have the wider 131mm hub to accommodate the extra sprocket on the cassette, and of course matching front wheels are also available.

10-speed to 11-speed

With a mechanical groupset, the addition of an extra sprocket requires a complete overhaul of the shifter design - but with electronic this isn't necessary as the extra click is just a question of software.

The ‘brain' element of shifting within the front and rear mechs is in effect the shift buttons just switching power supply on and off. So going forwards, if you're already Di2-ed up, you can save yourself many hundreds of pounds just buying the mechs, wheels (well a new hub body at least) and chainset. Factor in the possibility that you might be able to pick up a bargain 10-speed Ultegra 6770 shifter and it's clear that upgrading to 11-speed needn't cost the earth.

Disc brakes

The influx of road bike disc brakes is proving to be more snack than feast. While we're yet to be persuaded of the advantages of rotors on the road, and the UCI still debates their legality in the WorldTour, we're starting to see a steady stream from manufacturers. Shimano's hydraulic disc brakes are one of the more technically advanced options, thanks to the ability to tap into its mountain bike technology as well as its experience with designing shifters for electronic groupsets.

Still in its early stages, you shouldn't expect to see a Di2 hydraulic unit landing in shops any day soon. Initial versions follow a similar design profile to SRAM's, with the fluid reservoir positioned in the lever hood; the final design has yet to be confirmed. For the time being R785 levers and brakes are being designed around the use of a 140mm rotor with 11-speed hubs in a 135mm width and Shimano's mtb-proven Center Lock disc mount.

Frame manufacturers will no doubt be applying the pressure to get a look ASAP, and delivery is hoped for May 2014 - but no one is holding their breath.

Ultegra 6870 prices - new groupset breakdown

  • Rear derailleur Ultegra Di2 6870 £219.99
  • Front derailleur Ultegra Di2 6870 £199.99
  • STI gear shifters Ultegra Di2 6870 from £299.99
  • E-tube SEIS handlebar cable set from £89.99
  • E-tube SEIS frame cable set £209.99
  • E-tube SEIS wire lengths from 300mm £19.99
  • E-tube SEIS battery mount £99.99
  • E-tube SEIS battery - internal £129.99
  • E-tube SEIS battery - external £59.99
  • Battery charger from £64.99
  • STI gear shifters ST-R785 Di2 inc caliper £599.99
  • Disc brake rotor - single £54.99

This article was first published in the July 4 issue of Cycling Weekly. Read Cycling Weekly magazine on the day of release where ever you are in the world International digital edition, UK digital edition. And if you like us, rate us!

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