Suppose I want to upgrade from mech to di2 (both ultegra/hydraulic). I’ve read the old threads.
Am I right that I need:
– 2x mechs
– 2x shifters (hydro variety)
– junction box(es)
– cables
– charger

and that this short list will push me towards £1000?

Is there not an “upgrade kit” available? Merlin do advertise one but it includes brake calipers. I don’t need them do I? I can’t see anything elsewhere.

Is the MT800 display a MTB thing really? Or a reasonable and functional workaround on a road bike?

Am I right that I need:
– 2x mechs
– 2x shifters (hydro variety)
– junction box(es)
– cables
– charger

And a battery.

I wouldn’t bother with an MT800 on a road bike. It should work but I can’t see why you’d need it.

<edit> but if you really want to see that info you can add a Bluetooth module and display Di2 data on your Garmin/device of choice. </edit>

I looked into this and discounted it ans not really cost effective. I’m beginning to wonder if itmight be a better idea to buy a di2-equipped bike and swap the drivetrain – or even keep the bike if it’s the right one…

You don’t need new calipers, but it might be easier to sell on, or swap over to another bike, if the mechanical setup has callipers attached.

Ruling it out on cost grounds is where I am headed too @nbt. But if I do it, I will always have @onewheelgood to thank for reminding me I need a battery. Oops.
Thanks for the answers @tomhoward. Makes sense now. I’d probably move the existing setup onto another bike so I *would* want calipers, but I wondered why that was Merlin’s default pack.

Verdict – quite simple but extremely expensive.

Having ridden AXS on my MTB..I really fancy AXS on the road bike now!!!

EEEkk!

DrP

Verdict – quite simple but extremely expensive.

I’ve been looking into a Di2 upgrade myself, and reached the same conclusion. Plus the fact it’s no lighter, won’t make me any faster and will take a day to swap the bits over and setup.

I’d prefer SRAM for the wireless advantage but it means a new freehub (I think) and a few mates in the club have had issues with the rear mech battery vibrating loose and the whole thing not working.

FWIW I fitted the Merlin ultegra kit over Xmas – all pretty simple as I’d dragged string through the frame when I pulled out the mechanical cables so routing everything was hassle free. Depending on the condition of the mechanical stuff you take off you’ll recoup 450-600 quid by selling mechs, calipers & shifters – I sold the new calipers as that means the buyer can cut hoses to whatever length they need. It’s worth taking time to understand front and rear mech setup properly as it’s obviously not the same as mechanical mechs, but it’s lovely once set up.

I upgraded from 105 mechanical hydros to Ultegra di2 in early 2020.

Once up and running it’s really nice – in particular the front mech shift up onto the big ring which is effortless.

Having 1 battery only to charge seems an advantage over AXS – although clearly Di2 is a bit of a pain to get setup with all the wires to route.

If you do it make sure you really check the lengths of the wires you need. I got all of mine right except the rear mech to lower junction box (you need one junction box A and one B) – which I underestimated how fiddly they route it had to take was. So I had to buy a longer one which delayed the build.

I think I came to about £800 all in – but I shopped round loads of places for each part – and got a particularly good deal on previous gen Ultegra shifters as they came with post mount calipers (which I sold on eBay). This was as the pandemic was just kicking off so there was less of a shortage of bike parts at that time.

I wanted to upgrade my 105 bike to Di2 Ultegra a few years ago and deemed it far too expensive…so just went out a blew a load of money on a new Di2 equipped bike instead. 🙄

I hope I’m not going too off-thread with this – there’s a 1 x11 XT di2 available that the seller has said is off an e-bike & was connected to it’s battery. Would this kit be e-bike specific (on the pictured boxes, it looks like standard Shimano gear with no weird numbers) or could I get the relevant kit to use it on a normal bike for not too much money?

It won’t be ebike specific. You’ll just need a battery and a place to store it.

It’s a normal MTB – none of that internal routing lark – could I use the inside of the steerer tube (1 1/8″) or are the batteries too large for that? Other than that, are there any sensible external solutions? I’d be happy to use a bottle cage mount type of thing, just don’t want the bike to look like an amateur DIY electronics project!

Some of the Shimano Pro Koryak stuff is designed to store the battery in the steerer. Personally, if the bike isn’t internally routed and you don’t intend to modify it, i wouldn’t bother with Di2. There are ways to mount the cables and batteries externally, but they’re not great. Mine is stored in the top tube so that I can run a dropper.

“but I wondered why that was Merlin’s default pack” Shimano/UK importer sell that set up as a “upgrade” bundle (as well as groupset bundles) so just easier for them, helps for people who have power cranks etc

Ref cables, don’t for get to add a little more, so you got enough slack to connect the wires to junction box at the BB before fitting in frame.
Also Park tools do a nice internal cable kit with a Di2 end, worth getting if you like to make your life easier. 😉

Di2 is simply the best upgrade you can do to any bike.

The wiring system is fit once and forget. It’s straightforward to do even on bikes not intended for Di2 fitment. The benefits far outweigh any aesthetic short external cable runs (if necessary). I’ve only had to do this on MTB’s with droppers though.

You’ll need one of these if you want to setup the Di2 via your mobile

Shimano Di2 Wireless E-Tube Unit