Upgrade 105 to Ultegra Di2

Mossop

Hi... I have a big b'day comng up soon and with the spoils I'm hoping to receive , I'm toying with the idea of upgrading my 2015 BMC Granfondo GF02 to Ultegra Di2.

The GF02 has BMCs DTi (Dual Transmission Integration) so I know it is able to be upgraded... but I need some advice on exactly what I would need.

At the moment it has full 105 which has only about 700 miles use; so I'm thinking no need to purchase the full Ultegra Di2 groupset and to just keep the 105 BB, chainset, cassette & chain to save some pennies... but with the Di2 groupsets being heavily discounted right now (£859.99 ish for the Ultegra), I want to work out how much I'd save and if that saving is worth it over the added benefit of going full Ultegra!

So, I reckon I need the following:

Ultegra 6870 Di2 11 Speed STI Road Lever Set
Ultegra 6870 Di2 Braze-on Double Front Derailleur
Ultegra 6870 Di2 11 Speed Rear Derailleur
Di2 Junction Box A - E-Tube, 3 Port (SM-EW90-A) or possibly 5 Port (SM-EW90-B)?
Di2 Junction Box B (SM-JC41)
Ultegra Di2 Battery Unit -Internal Mount

... plus the cables. But this bit is confusing me slightly as there seems to be a kit (Di2 E-Tube Derailleur to Battery Cable Kit (Int.)), as well as individual cables (Di2 SD50 Cable and Di2 E-Tube Individual Wire Length) and I'm not sure which I need or if I need them all?!?

Is there anything missing?? ... or things I don't need??

... and maybe a nice to have add on would be the Wireless unit (SM-EWW01) as I have an Edge 1000;... if I have any pennies left. Do I need anything additional for this?

Any advice/guidance you can offer would be a big help... and if anybody has already done this on a BMC Granfondo, even better!!!

It's either a nice upgrade to Di2 or a watch!!!

Many Thanks

meanredspider

Look on the German sites - they will sell you the upgrade kit that you need at a good price. It's easy to install. If it's an internal kit, you'll need to remove the BB - depending upon what it is, you might need some extra tools or LBS help.

I think if you have new 105 then there's very little to be had from going Ultegra. You can change the chain and cassette when they've worn out. After that I guess you'll just have calipers and crank.

adz999

The only thing I would make sure of, is that your brake callipers are the 5800 series 105 callipers, as they are different to the 5700 brakes, i'm led to understand they have a different cable pull ratio, definitely worth the upgrade if not, vastly improved braking. I went from 5700 105 to 6870 Di2, its worth the upgrade!

this was useful during the install,http://www.globalcyclingnetwork.com/videos/sec-how-to/how-to-install-shimano-electronic-di2-groupsets/

JesseD

Go for full Ultegra, if you don't I guarantee that after a couple of weeks you will wish you did! You'll look at your bike one day and just think the 105 chainset looks wrong!

Plus from the reviews I have been reading on chainsets, the Ultegra is the stiffer of the 2, apparently stiffer (but heavier) than DA but I am not sure if there is much truth in that.

ic.

Previously I would have set just buy the gearset upgrade kit for roughly £670, but with the price of the full groupset now only £760 ish I'd go with that. Chainset, BB, Brakes, Cassette for £90 seems good value to me.

Sell off your 105 stuff for £200

gimpl

Also if you go for the 5 port junction box you can add a climbing button on the tops - best bit ever!

Mossop

Thanks for all the comments/suggestions.

I've gone with the full gruppo :-) ... and even thrown in the D-Fly wireless transmitter!