Cranky's Corner

After having my current road bike for 5 years I finally decided to upgrade to Di2. I was contemplating getting a new frame and building that up but since my CAAD10 is already Di2 compatible it just made more sense (to me) to go upgrade it.  My position is pretty well dialed on it and I’m not too keen on paying the current going rate for bikes these days so off I went to ebay to source some new electronic goodies.

My CAAD10 came stock with a Shimano Ultegra 6800 group set (minus the cranks as those are C’dale Hollowgrams with FSA rings), so that meant I would just need both derailleurs, shifters, battery, junctions and cables. To help keep costs not going completely out of control I wanted to say with Ultegra as other than a few grams there is really no benefit to Dura-Ace. Now I did float the idea of SRAM eTap as that would make installation a ton easier, but 2×11 groupsets aren’t easy to come by and they cost a premium, so Shimano it was. My choices were either the older generation 6870 group set or the newer 8050 group set. It seems shifting performance between the two were about the same (from reviews I read) with the biggest differences being the more customizable syncro-shift (i.e. auto shifting) and thinner hoods with better covers on the 8050 series. So with that bit of info it was off shopping for 8050 series parts where necessary, which is just basically the derailleurs and shifters, everything else is the same for all groupsets.

When all was said and done I was north of $1000 for all the parts. Now keep in mind I’m inpatient and I only bought items with a “Buy It Now” option on ebay and everything was either new or a take-off. You could probably get everything a little cheaper if you want to try your hands at bidding wars and/or get used items. I’m not opposed to used but in the 8050 range that was slim to none when I was looking.

My two biggest resources in this endeavor were GPLama’s videos where he did the same conversion himself and also the bettershifting.com web site, especially for cable sizing and how to design your system.  For reference here are all the parts required for a Cannondale CAAD10 size 52.

• Di2 shifters (Ultegra ST-R8050)
• Front Derailleur (Ultegra FD-R8050)
• Rear Derailleur (Ultegra RD-R8050)
• Battery (BT-DN110A1)
• Junction A (EW-RS910)
• Junction B (SM-JC41)
• Wireless unit (EW-WU111)
• Wire (lengths: 200mm, 350mm x2, 650mm, 850mm, 1200mm x2)
  [All the wires were actually purchased from Amazon]
• Battery Charger (SM-BCR2)

Here are the details on how my wires were routed along with cable lengths. This option gives me no free port on the right shifter for the climbing shifters but I never planned on running one of those anyway. Different bars with dedicated ports for internal routing can give you other routing options so YMMV.

Junction A –(350mm)–> Right Shifter
Right Shifter –(1200mm)–> Junction B
Junction A –(200mm)–> Wireless Unit
Wireless unit –(1200mm)–> Left Shifter
Junction B –(850mm)–> Battery
Junction B –(350mm)–> Front derailleur
Junction B –(650mm)–> Rear derailleur

For the rest of this post instead of outlining my installation I’m going to highlight some tips & tricks to help with yours as every bike might be a little different. There are plenty of videos online showing the installation and I’d recommend watching the GPLama video series 1, 2 or 10 times as I think he does a really good job at explaining the process.

1. Get the Park Tool IR-1.2 internal cable routing thingamajig. I’m not sure I would have done this without it. Yeah thread, vacuums and some wishful thinking might have done the job but this was just fast and easy. I also got the Park Tool EWS-1 electronic shift tool to aid in the installation/removal of the Di2 wires. You could also go with the Shimano tool but I liked the Park Tool form factor better and it’s not like it cost much more.
2. If you don’t have a Di2 compatible seat post (I didn’t) you will need a way to secure it inside your seat post. I chose the PRO Di2 seat post holder. There are other brands but this did the trick with my C’dale seat post. I did have to shave down the ribs for it to fit properly but in the end it worked just fine. Of course you could purchase a Di2 seat post but that adds more cost.
3. There are 2 types of Junction A boxes you can get, under the stem (old school) or in the end of the handlebar (new school). The CAAD10 didn’t come with handlebars that would accommodate the new school junction box so your choices are go with old school junction under the stem, buy new handlebars or just drill small holes in your bars for the cables to pass through. These holes need to be 5-5.5mm away from the end of the bars on the underside and should be big enough for the Di2 cable end to pass through. Do this at your own risk and if I had carbon bars I probably wouldn’t have done this but with the aluminum bars it doesn’t concern me as it’s in a non load bearing area and lets be honest, the factory isn’t doing anything different other than having some fancy machine drill the holes. If you do decide to go this route just use a file to de-burr the holes, inside and out, and then I used a sharpie to sorta make it look nice, not that anyone would ever see this. Also when I taped down the Di2 cable in his area, I started behind the Di2 cable, covering about half of the hole and then wrapped over the cable securing it in place. This puts a bit of tape between the cable and the hole and then secures it in place so there should be very little chance of chafing.
4. Connect all your Di2 items on a bench first to make sure everything works before installation. I also connected my computer to upgrade the firmware & get the wireless unit set up.
5. Use a pencil to mark the position of the mounting bracket on your old shifters. The pencil lead shows up easily on the black bars and this will make placement of the new shifters a little easier. 
6. Run all the Di2 wires loose first and make sure everything works before hiding everything away.
7. The CAAD10 has a BB30 bottom bracket and no inner BB shell so there is no need to remove the bearings as the 30mm hole is plenty big enough to pass all the wires and Junction B through. This will be largely bike dependent.
8. Since there is no inner BB shell on the CAAD10 there is some risk of of the wires coming in contact with the spindle if they are not secured or shielding somehow. I’ve seen people use hot glue or tape to secure things inside the frame but there is a small risk there should either of those fail as this is a blind area of the bike. Instead I fashioned my own inner shell from a water bottle (not a bidon, but rather specifically a Life Wtr bottle). I cut a section of the bottle that was just under 30mm and then slit one side of it. I then coiled it up tight, passed it through one of the bearing and let it expand inside. Presto an inner shell and all wires secured out of the way. If you need to remove you just grab one of the cut ends and pull through the bearing (thats why it was cut at 30mm to make this easier). 
9. I worked from the back to the front securing/hiding cables. Rear derailleur, front derailleur, battery, junction B into down tube (wrapped in bubblewrap), inner BB shell, then handlebars/shifters and lastly Junction A.

I think that about covers my system design along with any tips/tricks I learned along the way. Other than that I just followed the Shimano derailleur installation/adjustments from the dealers manual and everything went smooth. Overall I’m really happy with how things went and shifting is superb with the new groupset. I’ll report on any issues but as of right now I’m definitely a convert. Feel free to reach out with any questions and I’ll do my best to answer and with that, happy shifting!