Di2 Upgrade question(s)

[jwalther]

Our 2013 Co-Motion Supremo tandem is equipped with Ultegra 6770 components. I'm thinking about upgrading to 8050, and assume it's pretty much a plug and play swap for the shifters and derailleurs? I'll obviously be getting a new wheelset and cassette. I'll probably move to an internal battery eventually, but plan to stick with the existing external battery until it dies. Is there anything else I should consider?

[TerryDi2]

If your Tandem is 6770 Di2 then it probably uses the SM-EW67A-E Junction A.
While this Junction A will work with R8050 Di2, keep in mind that you will have to upgrade it to either SM-EW90-A/B or EW-RS910 / SC-MT800 when you upgrade the battery or the battery mount.

Hardware-wise you can get away with just upgrading both derailleurs. That's all.

However.
Your battery mount will need to have its firmware updated. It will (probably) not work with the newer components without updated firmware. If you need to update its firmware you'll need to visit a bike shop - updating firmware on SM-EW67 bikes is done using the SM-PCE1 / SM-PCE02 diagnostics tools.

I have written something on upgrading Di2 bikes here by the way, it's probably helpful too ;-)
https://bettershifting.com/in-depth-guide-on-upgrading-your-old-di2-bike/

The Di2 compatibility charts can be found here: https://e-tubeproject.shimano.com/pdf/en/HM-CC.3.4.3-00-EN.pdf
You'll want to look at page 3 (Di2 with SM-BMR1 / SM-BMR2). If you can connect all the boxes then the components are compatible with each other.

[radsmd]

Our 2013 Co-Motion Supremo tandem is equipped with Ultegra 6770 components. I'm thinking about upgrading to 8050, and assume it's pretty much a plug and play swap for the shifters and derailleurs? I'll obviously be getting a new wheelset and cassette. I'll probably move to an internal battery eventually, but plan to stick with the existing external battery until it dies. Is there anything else I should consider?

May i ask why you want the upgrade? Is it the extra gear or wider gear range? I dont think you would be gaining much with the “upgrade” other than a lighter wallet and less time.

[stien]

I would do derailleurs and 11-34 cassette if that makes sense for your terrain. That way you get to keep your wheels, shifters.

I did 11s Di2 for our road tandem and ran with 50/32 and 11-34 for hilly long days in the Berkshires and was very happy. That was a mid cage 8050 RD and 6870 FD.

[Nick12]

I have written something on upgrading Di2 bikes here by the way, it's probably helpful too ;-)
https://bettershifting.com/in-depth-guide-on-upgrading-your-old-di2-bike/



This is amazing!! Thank you so much for taking the time to put together this article. The Di2 product names are a nightmare and I felt like my brain was about to implode with all the various letter/number combinations! Your article is superb at laying it out in a concise and easy to understand manner!

I've been holding out on getting an electronic groupset as I wanted to keep my bike rides simple and I didn't want to worry about one more thing to charge. I stumbled across a few articles which convinced me that battery life is not really an issue (particularly with Di2) ... and everyone else in my group ride has Di2 ;)

So figured, why not! Take the plunge! So I snatched up a Di2 6770 for peanuts, and will be picking it up tomorrow. I started researching upgrading to 11-speed and I'm so happy I found your article (Google kept pushing me to that FitWerx article, which is elementary compared to yours).

I think my plan will now be to first get rid of the external battery and convert to internal, mainly so I can do my own firmware updates and improve the aesthetics. I'll ride around with the 10spd for a bit then upgrade the FD and RD if I think its worth it. I also have an 11spd disc bike, so this groupset is really intended for coffee rides when the weather is nice, so no real need for that extra cog, although syncro sounds cool. (I'll do my purchases through your links as my way to thank you for writing the article and to keep the page up for anyone else looking for the info.)

Now I just need to find a nice steel bike with Di2 routing!

Thanks again for the article.. and good luck to the OP with upgrading your 6770!

[TerryDi2]

This is amazing!! Thank you so much for taking the time to put together this article.
Thanks again for the article.. and good luck to the OP with upgrading your 6770!

hah, good to hear - any improvements or suggestions are welcome too, of course.

The Di2 plug itself is 5mm, so that is something to keep in mind when trying to route it through the frame. They usually do not fit through internal cable stops.
(though I have to admit I took a small drill to my old bike's cable stop and made it big enough for the plug to fit through:)).

On externally routed bikes the SM-BTC1 can be an option too.. but personally I don't like the way it looks.
It is a frame mounted battery holder for the internal battery. It is also a 6 port (1 in use by battery) junctin B.

[jwalther]

That's incredibly helpful Terry, thank you!

Why the upgrade? More want than need for sure. Another gear is always nice to have, and wider rims should provide a slightly more comfortable ride. Upgrading the battery now or down the road allows integration with my Garmin, and that appeals to the data junkie in me. As for the cost, I honestly believe it's a good investment in the value of the bike. I plan to upgrade the shifters, FD, RD, brakes and wheels for a total spend of $1600 +/-. I should be able to recoup half that cost selling off the old components. I'm confident the bike will be worth at least $800 more after the upgrades than as it sits now. While I don't plan to sell any time soon, looking at the balance sheet it's a wash or net positive.

[jwalther]

Project finished. I did everything but the wheels, after determining there is probably insufficient front fork clearance to accommodate a wider rim running 28s. Very happy with the results.

[Nick12]

Care to share pics of completed project?


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