There are many challenges and the biggest question is 'why'. As in going DI2 won't get you any speed benefit, and will cost you $$$$$. Ok, I've just moved 10sp metchanical to full new Di2 hydro disc and the one thing I really like is being able to change gear from base bars, but I equally am hating the syncro shift you end up having to use (12sp).

So some challenges you have. At moment only bar end shifters are the 11sp, and whilst those are one of the few items that can work with 12sp, you'd need to connect them to the comms module to get the latest firmware installed before it will recognise.

Not sure about cable routeing on the p2 - where are you mounting the battery and then running the cables to the shifters/mech.


Honestly, the cost of components means if you do want to do this then buying a new bike is a serious consideration in value terms. I accept that if you're well stocked with a range of rim brake race wheels that may mean the cost isn't as comparable, but then I still come back to the cost of going to Di2 over the benefits.

Oh, in terms of what you need, look at the bettershifting website - has several really handy guides for you.

Don't even think about buying the parts from a local bike shop. Complete ripoff.

So if he doesn't buy from LBS, out of interest how would you recommend updating the bar end shifters when they arrive to the required firmware to be able to connect to the mechs/battery?

It started with just upgrading to ultegra or DA mechanical. Someone said if you're gonna upgrade....

I really like my bike and dont imagine myself doing this for many more years so a new bike seems silly (but then so does di2 by that logic).

No bike shop for sure. I have an opportunity to buy a barely used rim brake tarmac (very cheaply) from a friend and stripping it down for the di2 and only needing to buy 2 more wires, a junction box B, bar end shifters and grommets. I could then sell the tarmac frame or buy a road bike di2 groupset which seem easier to find.

Likely sticking to 11 speed and piece-mealing it through ebay and such.

Ok, more sensible. So you'd still need the shifters and then additional sprint buttons to add to your base bars for the second shift position. You'd be botching it a bit to avoid buying new brake levers with the buttons integrated but should be fine.

But has your friend added the bluetooth unit to the bike so you can connect and update the settings? Otherwise you'd want/need one of those. (WU-111).

If you're not adding the base shifters you are literally spending money for no reason at all.

Yup, left base shifters off of my list by accident. Need them too.

I did it about a year ago on my road bike - went from 10 speed mechanical to 11 speed Di2. By the time I’d added the Bluetooth unit, the bar end junction box, the climb shifters it ended up far more expensive than I had estimated and I wished I hadn’t bothered. And then I rode it for a bit and I was so glad I bothered. I enjoy riding the bike with di2 way more than with mechanical. I also enjoyed the experience of doing it (I do all my own mechanics including bleeding MTB brakes/basic servicing of suspension) but had never dealt with di2 so it was a cool learning experience. I bought as much stuff second hand as I could find over a couple of months and then added the few things new that I couldn’t find.

I presume you've already discounted going for the much easier to install sram wireless system? I was contemplating which electronic set-up to add to my TT bike to make adjusting the front end a lot easier since I was going to be doing a lot of aerotesting. One rear derailleur, a pair of wireless blips and a pair of blip holders from leap components. Job done in 5 mins. Relatively cheaply too.... No wires, blip boxes etc...

I would not do it.
The whole purpose (for me) of electronic shifting is to be more simple, there is no way I would change a mechanical groupset to go for a wired electronic groupset.
I bought sram wireless blips and derailleurs, and for the mechanical part(cassette, chain, crankset) I went shimano. No more wires, no need to change the HUB, took me something like an hour to set it.

I just did this. I searched for a used di2 TT set on ebay and found one for about $700 bucks (11 speed ultegra).

Super simple to install. Some of the wires are a bit long, but I just tuck them into the tubes.

It's so much better than mechanical. Wish I'd upgraded years ago.

Can you guys tell me morre about the sram set up. I can keep most shimano compenents? I'm a touch confused.

I started looking on ebay yesterday for exactly what you just described and that price would be great. I didnt see a full set but lots of compenents that I could piece together and make work, but I'd prefer a full set.

Prior I had been looking for new at retailers.

I check the classifieds here occasionally. Is this something that goes up for sale regularly or would this be few and far between?
I guess I just need to start hawking ebay at this point. (if i dont take it all off the tarmac)

I would first try using the battery charger to connect them to your PC.

If that doesn't work, buy an SM-PCE02.

What SRAM derailleurs did you use for this? My understanding is that SRAM derailleurs need to use the flattop chain, which require the SRAM cassette. So then you need to also change the freehub body. Is there a SRAM derailleur that is compatible with a Shimano 12 speed chain and cassette?

Hi, to go the cheapest yet fastest setup possible, I bought :
- sram rival front and rear deraileurs
- sram wireless blips
- shimano ultegra crankset r8100 , 12s
- Shimano duraace chain, 12s
- shimano ultegra 12s cassette


That way, I did not need to change the freehub or the botton bracket.

To be honnest, I do not feel good relying on the wireless blips. I will buy a second pair and put them on the hoods to make sure that I have a backup solution during races.

This setup has been working very well, but I only have been using it for 4 months.

the apex cassettes fit on 11-speed freehubs. you still need a flat-top chain though

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the world's still turning? >>>>>>> the world's still turning

U could also ditch the front derailleur and go 1X, save some $$. Also have a look at 2nd hand bikes, might be cheaper to find an old bike with electronic rather than buying a 2nd hand groupset, the latter seem to be going for stupid money.

I believe changing from mechanical shifting to electronic is the best bike upgrade anyone can do. Mostly being able to shift from the levers not just the aerobars. It's also pretty easy to do on your own.

Shimano sells Di2 frame grommets in a couple diameters.

Figure out where you will put the junction box and wire layout. I'm sure the manual of the Di2 version of your bike will show this. Measure the length of wire needed with a string from the component to the either the junction box or battery then add a couple inches.

Don't get 12 speed, stay with 11 speed. You can easily find a used but in good condition Di2 RD and FD. Finding TT brake levers and aerobar shifters should also not be too difficult. I would buy new wires and battery/charger. Make sure to get a Shimano wire connector tool.

Finally watch some videos on how to route the wires and buy a Di2 wire routing kit. If you keep the existing shifter cable in the frame but remove the housing you can attach the Di2 wire at one end and snake it easily through the frame.

Initially adjustment of the Di2 FD and RD is much easier than mechanical in my opinion and forever shifts flawlessly.

I bought a rear force axs derailleur and 2 wireless blips, and as mentioned previously the leap components blip holders. That was all I required, and I run it with an ultegra 12spd cassette and Ultegra 12 spd chain with no issues so far (9 months of use). Literally took 5 mins to install, no faffing with connection boxes, correct wire length, hiding wires/boxes etc etc.....

I am doing the exact same project with the same bike (a little older P2). Better shifting has a great article on how to do it.

Here is a link to the article.

Build a 12-speed Di2 Time Trial / Triathlon bike (bettershifting.com)

I bought the parts online. I am going to 12s Ultegra mostly with some DA parts too. Excel Sports Boulder sells all of the wires, adapters, junction boxes, etc. I stripped the frame and used string to measure all cable lengths.

There are really only two potential curveballs with the set up. You need to update the firmware for the 12s Bar end and base bar shifters. You also need to use one wiring standard for the front of the bike, and have an adapter that changes the wires to the back. I have another 12 s Di2 road bike and I like the charging through the rear derailleur port. I am guessing Shimano will soon make the 12S semi wireless like they did with the road groups. I dont mind the shifting - I have it set up to run through all the 11 cogs on the rear derailleur before it shifts to the small, then it stays in the small front ring 2/3 of the way down the cassette until it goes back into the big.

I live in a very hilly area so 1X is a non starter for me and Shimano front shifting is incredible.

I am anti Sram and cant get over it without some expensive counseling so I am sticking with Shimano.

If you have never put together a Di2 system, it can be a bit intimidating, but like a lot of things, once done, it is super simple. I tried Di2 on a gravel bike so I could shift from the regular levers, add a climbing shifter and shift from my aerobars and after that I could not stand mech shifting. My TT bike (an old P2C from 2008) has the simplest system possible.
1. climbing shifter attached to end of bar
2. Junction A box
3. short wire to the battery in my top tube pack.
4. really long cable to the rear derailleur
5. rear derailleur
(I don't shift the front that often and it is super fast even as mech)

All of that was off of ebay for about $250 and now it is super fast at shifting like my other bikes.
I would argue that it does provide a performance advantage because I shift 3 or 4 times as frequently because it is so smooth and effortless. The only way electronic does not shift better than mech is if you meticulously maintain and adjust your mech and even then you are going to have to account for cable stretch and wear of components.
As for wireless, I would not want to have to have to keep track of multiple batteries, personally. Yes, iniital set-up might add a few minutes, but then you never have to touch it again; as long as you account for cassette and chain wear it will shift perfectly once you have it set and then there is one battery that you only have to charge once in a blue moon.
P.S. in response to the last question. I slightly widened the frame entry point and then taped the cable down with clear tape.

My first question, is your 2019 P2 frame compatible for Di2?

Two years ago I switched my road bike from mechanical to Di2. My Scott Foil road frame was not Di2 compatible, which means the holes for the front and rear derailleur cables on the frame were not large enough to fit the head connector portion of the Di2 wires. So I could not simply insert the wires into the frame as I would cables. The solution is to cut the two wires in half for front and rear derailleurs, insert the cut end into the frame holes, and then slice and solder the wires back together within the bottom bracket, then shove the wires back into frame and reinstall your bottom bracket.

Overall, the upgrade was 100% worth it. I bought all the Di2 equipment off ebay and craigslist and it cost around $800. Just watch youtube videos, educate yourself and you will be mechanically inclined in no time.

Converted my Felt B16 to 11spd ultegra di2 last year as a 1x set up. It was awesome but I bought a Speed Concept this year. If you decide to go ahead with this PM me because I have the di2 mini group to sell- will probably post in classified soon.

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