Di2 Upgrade - Anyone ever done this?

Hi Everyone,

I’ve got a 2018 Cervelo R3 Ultegra Disc and want a new toy for it.

Has anyone ever done an Ultegra Di2 upgrade?
Is it a nightmare to do?
Do i need lots of special tools?
Is it worth it?

Few weeks ago I bought a Ultegra di2 groupset and had my lbs set it up on my Tarmac SL5.

Has anyone ever done an Ultegra Di2 upgrade? Did loads of research, but asked my lbs
Is it a nightmare to do? Depends on frame and knowledge
Do i need lots of special tools?
Is it worth it? 200%


Has anyone ever done an Ultegra Di2 upgrade?
Yes. On a propel
Is it a nightmare to do?
Nope… once the bottom bracket comes out easily
Do i need lots of special tools?
Only bottom bracket related
Is it worth it?
In my opinion yes… but buy all the options at the outset

Assumes your bike is ready for di2 but a frame that new should be.

Has anyone ever done an Ultegra Di2 upgrade?

I’ve done an installation, so kinda?

Is it a nightmare to do?

No. Actually looks like you might be ok, looking at the R3 manual; there are no obvious gotchas. Looks like it might be a solid BB shell and you access the guts of the bike from a port underneath it. Wiring diagram looks straightforward: https://www.cervelo.com/media/gene-cms/r/3/r3_disc_manual.pdf
One caveat about the wiring in the next section though…
Also see if you can get the Cervelo specific port covers mentioned in the manual though. Dunno if they have a spares website.

Do i need lots of special tools?

Di2 specific tools are limited to that plastic doohickey that you use to connect the wires and this came with my groupset (also I think it costs about £3 separately, thank goodness). What I think you’ll need in addition from looking at the wiring diagram is a routing kit e.g. https://www.parktool.com/product/internal-cable-routing-kit-ir-1-2 which is the one I use and it is :kissing_heart:
You’ll probably want to bleed your brakes after swapping the levers over, you’ll probably lose a little oil. Ultegra R8070 needs an additional part on top of the standard bleed kit like this: https://www.tredz.co.uk/.Shimano-ST-R9120-Funnel-Adapter-and-O-ring_225141.htm but my levers came with one of these.

Is it worth it?

Electronic shifting is great. I also found it quite fun to build. It’s hard to say whether it’s worth the few hundred on top of a mechanical road group with STI shifters though. On my TT bike with a non-indexed front bar-end shifter though, I would sell my soul to get rid of that bloody thing :laughing:

Having gone to Di2 2 years ago, I would never willingly go back to Mechanical. In my case, Ultegra 8050 is actually lighter than 8000, more reliable, the charges last for what feels like ever, every shift is fast and exact and smooth, its just an amazing system. Another advantage is being able to microadjust the detaillers on the fly without reaching down, if needed when swapping between a wheel and a trainer.

It’s not a nightmare to do, one motivator could be that you know once you set it up once you never have to mess with it again, unlike with shift cables. Some say you need the di2 wire insertion tool, but you can use your hands.

Totally worth it, 11/10 would recommend, especially if you ride in less than perfect climates.

I did it last year on my '18 Cervelo S5, which I assume to be very similar in design. I’d never done any work on my own internally cabled bikes, so this was my first foray into it and although there were some frustrating moments, I just took my time and wasn’t a big deal. I didn’t even remove the bb when I did the install, just wired it around the bb. The most frustrating part of it was probably doing the internally cabled handlebars, the rest of it was a piece of cake. But it probably helped I started with a frameset and not a fully built up bike.

“Is it worth it” is a question that can really only be answered by you.

Personally, I’m not a huge fan of electronic on a road bike. I prefer the feel of mechanical shifting. I have had two go’s at electronic (Ultegra 10 spd and now FSA WE) and both times I see little advantage to it. It works roughly the same as mechanical, arguably a touch slower.

You won’t be any faster with electronic, that is for certain, hence the reason the question of “worth” will depend on you and your wants / needs.

The primary reason I switched this time from mechanical to electronic was for the hood shape. The mechanical / hydro Ultegra brighter was pretty bulbous and ugly. It was comfortable, but big. I absolutely love the shape of the FSA brifters, so from that perspective, it was “worth it” for me.

Converted my 2013 trek 3.1 madone two years ago and it killed off any desire to buy a new bike - it’s so reliable and easy to tune. Trickiest part was just routing cable around BB but didn’t have to remove it. Shipped my bike to France and just bolted the RD back on, plugged in cable, and done. No tuning needed. Was also tired of repeated cable fraying in the 105 brifter. Every 3-5k miles, it would start getting sluggish and eventually jam up. I live in a hilly area and ride to power targets doing outdoor workouts, thus I shift a lot.

Got even more awesome when I setup Redshift quick release aerobars - combined with some used di2 end shifters off ebay, I can add/detach them whenever I want using an extra junction port under the stem. Under 30 seconds to install or remove aerobars that include bar end electronic shifting has also quenched my interest in a TT bike for now. This kind of versatility is a hidden strength of di2 for those that can’t or don’t want to buy and maintain multiple bikes. For now, I’ll say it saved me $9000 total. :sweat_smile:

Has anyone ever done an Ultegra Di2 upgrade?
Yes-- Giant Propel Disc and Felt IA16

Is it a nightmare to do?
Not necessarily. Make sure you buy all of the correct parts and wiring lengths-- along with anything else you may not normally think of. I forgot one extra wire from the handlebar junction box back to the shifter. Also had to buy a replacement bottom bracket on the Propel but was only ~$18 though.

Do i need lots of special tools?
Not really. The park internal cable routing tool (IR-1?) makes routing internal wiring easier but you can probably use some other method if you don’t want to buy that. Like someone else said, may need a special tool for removing your bottom bracket if you don’t have it. I had the BB30 tool already but had to buy the Shimano tool, for instance.

Just installed a new GRX Di2 on a Canyon Grail I snagged from their outlet. Honestly it’s about as easy as it gets, if it connects, it works. You don’t have to worry about the order you connect things, so you can figure out your own routing. The “hardest” part is planning how you want to do the cable routing and measuring to make sure you get the right lengths. At $20-$25 each, you just want to be really sure you’re not too short. Once it’s all hooked up, dialing in your shifting is a dream, and then it just works, like perfectly. I spent far more time bleeding hydraulic brake lines, than I did worrying about the Di2.

Only negatives are $$$ and the occasional “cycling purist” giving you a hard time about it. Granted I’m a tech-head, so if there’s any way I can mess up something purely mechanical by putting bluetooth in it, I’m probably going to.

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I think Di2 is worth it when you get it from the outset.

As for an upgrade to an existing bike, unless some part on your current drivetrain is trashed, I’d sooner spend the money on a new set of wheels or cockpit components.

I’ve already got the wheels, and gone tubeless. I can’t imagine having 2 great bikes as just…why? so i am going to scratch this itch with Di2.

Thanks everyone. Awesome resouces and advice.

Now i need to go and ask my wife before i buy :rofl: :joy: :rofl: :rofl: only joking.

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A Question: Can you just remove the existing brake/shifters and connect Di2 brake/shifters in place, and then thread up all the gear wires etc, or do you also have to do anything with the brake system?

Probably will need to bleed brakes, assuming you have Hydro.

The BT was worth it’s weight in gold during a spin about 2 weeks after install. I had reached the turn around point and my left shifter stopped working. I could see the cable that wasnt right but couldnt get it to seat properly on the road. With the phone app I was able to re-program the right shifter to do what I needed to get home (combined with full synchro-shit).

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Yup, done it on a Gen 2 Speed Concept, upgraded the entire thing from mech to Di2 and basically rebuilt the entire bike.

It is not a nightmare assuming you do your homework. Make sure you read up on how to do it, measure your cable runs, make sure you get the correct battery (one that can do synchro), the correct A junction (I put mine in the plug in and made it very sexy), get your B junctions (1 or 2 depending on your A box configuration) and if you do it piece by piece you can save money but understand there is no “easy” manual for it. You can also buy it all on ebay and spend maybe an extra hundred or 2 to limit headache; almost suggest this is better. Also think about your battery placement, I suggest in the seatpost if it can fit, but wrap the battery in foam and stuff it in. Also I suggest the wireless controller.

You need the Di2 plug/unplugging tool. Also suggest looking at how to get into the BB area and potentially get a tool if you need it to be able to work in the BB area. Also some guide wires may help, you can macgyver some old shifter cables to help. You also need the charger and the cord. You absolutely need that.

It is worth it if you have the funds. Does it make you faster?

Is it nicer in every way and make sexy sounds and is just satisfying in general?



Double check on the model of shifters you currently have vs the DI2, but I was able to use the existing calipers and brake line when I swapped mine. Did need to bleed the brakes as someone else mentioned.

I did this on a Scott Addict and it was totally worth it. The kicker is going to be the hydraulic brakes, I’m not sure, but I would think you would need to bleed them after changing to the new shifters.

I jumped into this and got all the bits and have it all 95% installed already - I’m just waiting for delivery of a couple of long cables to finish it off. It takes a little bit of working out but it all makes sense eventually and it’s actually not that hard.
Bleeding brakes is about the suckiest task on the planet though. I’m still not sure if i’ve got all the air out…

It’s been a great little lockdown project. I’m looking forward to getting out for a play, probably tomorrow.

I hear ya on the brake bleeding. I find taking it for a short bumpy ride and then doing another follow-up bleed usually shakes free any bubbles stuck in the line. It should feel alarmingly responsive when you have it done right, luckily you don’t have to do this often…

Congrats on biting the bullet, you’re about 2 months behind me doing the exact same thing.