Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

"On our scale, the shifters are 57g heavier, the front derailleur is 43g heavier, and the rear derailleur is 49g heavier."

Sounds about right.
The "big" difference in groupset weights is down to savings on brakes, cranks etc as well.
All the other di2 parts are the same between the two as well.

So 150g hardly worth it.
That's only 150ml water.

The Garmin shifters are fun, I'd not choose a groupset based on them though.

Having run 9070 and 6870 back to back there's nothing in it from a shifting perspective.

So, it all depends on where I source the shifters basically. I'm looking at the Diverge bikes and the frame appears to be the same across models just the groupset spec changes so I could buy their 105 bike and strip it, fitting Di2 and hydro shifters. Sound feasible?

What I did. Bought teh cheap cayo then stripped and sold groupset and fitted ultegra di2.

Do you save much money doing that?

One thing - make sure to use the Shimano rings, they do make a big difference to shifting performance (at the front, obv's).

yep, they are great bikes on paper, another worthy mentions are Cayo disc and genesis datum. Genesis can be bought as frameset for £799 (due in April).

£1600 for DA Di2, Ultegra is £600 cheaper:
http://www.planetx.co.uk/i/q/ZXSHIMANODADI2/shimano-dura-ace-9070-di2-groupset

6870 £718: http://www.vaneyckstore.be/en/p/ultegra-di2-6870-11-speed-groep
9070 £1470: http://www.vaneyckstore.be/en/p/shimano-dura-ace-di2-9070-groepset

The Focus would fit.
The Datum is too short and head tube is too long, like the Giant Defy we measured up.

Yeah Datum is MAMIL fit .. 140mm -17 stem?

Urgh! forruns!

I'm not running any silly stems to fit a bike. I already have a short list of candidates so I don't really need more. They all look feckin ugly though. Suits my current stable of bikes, I guess.

Diverge also fits like Datum no? Cayo would be my choice if I were you.

That shop for groupset is legit cc/ @dubtap

6870 is crazy cheap!

No, Diverge has longer ETT and shorter top tube to suit people like me who can actually bend in the middle. Why would I buy a Focus and not a Spesh? Priced about the same.

Does that Belgian shop also include the BB motor or do I have to buy that separately?

ha! There is this too: http://www.bike-discount.de/en/buy/shimano-ultegra-di2-6870-st-r785-hydraulic-electric-kit-internal-internal-401953

Hydro disc 6870; you need to add cranks, rotors (adapters), chain and cassette.

Is there a different hydro group or is it just the levers that I need to worry about?

"rotors (adapters)" - what's that then? The discs will come with the wheels right? I won't need to buy them separately unless I got a non-disc bike to build from, which seems a bit silly.

Rotors are purchased separately. Depending on your frame and rotor size you might/might not need adaptors to mount calipers on. Don't draw parallels to rim brakes in terms of expense and amount of stuff you need, the whole disc brake thing is to shift more shite at £££.

There isn't an official hydro group; some retailers are just creating a bundle by mix and matching. But for a disc brake road bike that should do with the bits that you need to buy separately.

So, I'd save a lot of hassle (but less money) buying something already Di2 and disc. I'm not actually sure that exists - maybe the Diverge Pro Carbon? Other options that fit: the Izalco Max Disc, Pivot Vault

Actually the Trek Domane 6.9 Disc is Di2 w/ hydro, but it's £6000

When we're in the Brave New World, everything will be disc and we won't have to worry about compatibility... riiiight

Domane?!?!?? You mad? Headtube is taller than the shard. More MAMIL than Datum.

On paper yes it should be cheap but thats not the case with Disc Di2 bikes; there are substansial savings if you can purchase a frameset (Trek sells framesets btw) or if you get a low spec (but same frame) shift everything on there for Di2.

Maybe I read the wrong value (not the first time, I'm looking at you 58cm Ribble Audax). The HT measurements on the M and L Datum are ok and the M might work with its Top Tube of 561mm.

The Domane is at the upper limit of HT at 175mm and the ETT is a bit on the short side but with an extra 10mm on the stem could work.

I'm erring towards the Spesh for the simple reason that their bikes work well and it seems all the Diverge models use the same frame and it's just the build spec. that differs. So I could buy the £2500 Comp, sell the group and build it up to be better than the £4500 Pro Carbon. There's a Pro Carbon frameset for $2200USD but no bastard in the UK seems to have it and bike shops are shit at replying to my emails about it. Time to tweet Spesh.

If they dont sell frameset here I wont be surprised. That means you cant buy it as a frameset here. Many brands do that.

If you like Spesh/Diverge go for it. I think Datum is better value at £799 frameset; I am partial towards it aesthetically.

Also given you are riding in Murica if any issue with Spesh I'd imagine they could be solved easier than Genesis.

I'm not sure it would play well with all the other Specialized bikes in my house. They need an S-Works version so I can complete the set.