We had our first introduction to ‘electronic shifting’ late in 2008 when Shimano launched some press Di2 equipped bikes – there were immediately both sceptics and fans of the idea. We though we’d take another look at the Di2 system and see if any of the initial fears and concerns were realised.

Electric systems on a bike?! What if it rains? How long would the battery last?…………….Wow, if I press this button I change gear – How cool is that!

Shimano Di2 replaces the usual mechanical derailleurs, shifters and steel cables for derailleurs with servos, shifters with buttons along with a battery and electrical cables. They’ve managed to integrate these neatly and without them looking too bulky and heavy. The total weight of the groupset was claimed at 67g lighter than the 7800 DA it replaced which if you bear in mind that it includes a lithium battery and a few more cables, is impressive – it also shows how much lighter the 7900 chainset is!

All looking good so far, this just left the price…over £2400 when it was first released. Prices have since come down though at its current £1900 it isn’t something you’d buy on a whim. However after using it most people wouldn’t go back.

What do I get?

Di2 Rear Derailleur	A rear mech with an extra box on the back which houses the motors and electronics
Di2 Front	A front mech with an extra addition, this box also houses the main ‘brain’ of the system.
Shifter	Shifters which instead of the usual shift levers use buttons to shift up and down – a very strange sensation shifting from the small to big ring at the touch of a button.
Battery	This is how the system sits on the majority of bikes, although some manufacturers now have come up with novel places to place the battery – under the saddle or underneath the BB.

This and you need two cable sets. One which connects the shifters to the battery/control unit and another which connects the derailleurs to the battery/control unit. The chainset, brake calipers, chain and cassette are all standard 7900 – top quality and lightweight.

What if it rains?!

So far Shimano’s Di2 has gained great praise for dealing with all the conditions a rider can throw at it. Rain, snow or mud, the gears still work and this has even allowed Di2 to feature on many cyclocross bikes. The connectors and battery are all sealed and water ingress is not an issue we’ve heard of. Given its use on Pro Team bikes in all conditions it must be reliable.

A Di2 system working just fine even when coated and clogged with mud – Nothing a quick hose and some lube won’t fix!

Di2 Cross

Will my battery run out mid-ride?!

Not that we’ve heard, the 7.4volt Li-ion battery is said to be good for 1000km of shifting and has an indicator to warn you of low charge. Obviously the distance will depend on your shifting patterns but after the initial showing off/novelty of changing gear at completely the wrong time to try and catch the system out you don’t need to worry about battery life.

Other features of Di2 are the auto-trim action, a two-part big to small chainring action (to prevent dropping the chain) and a crash mechanism on the rear mech which lets it move inwards if it hits the tarmac.
If you’re still unsure, take a look at who’s using it in the Pro world.

HTC Di2

Sky Di2

Garmin Di2

Given that these guys ride 1000’s of KM each year in training and racing, they wouldn’t be riding on Di2 if it had constant issues or regular problems. Since its releases Shimano have since added some more products – a thumb shifter for the classics riders which allows shifting while on the tops and finally the wiring kit for using TT bars is widely available. A lot of bike frame makers are now introducing ‘Di2 ready frames’ which have routes for internally routed cables – giving you a very neat and very smart bike. Also with the majority of people in the cycling world having ridden, played with or raced on Di2, the understanding of the system is thorough and most problems are easily remedied. If you have any more questions or queries about the Di2 please get in touch with us here at PBK , we have stocks and all the items you need to bring this revolution to your bike.

Click here for our Shimano Di2 range.

P.S as it happens, June’s copy of Velonews has just landed on my desk and on the back cover is a Di2 advert. Some of the quotes about it: “I was not disappointed. It’s magical, quick and intuitive” followed by “Truly a game changing technology”. If you ever had any doubts about Di2, now I think is the time to dispel them, while it will probably never become a mainstream item Di2 is sure to impress and perform.