I hacked into my Di2 and P5 Tweaks...
I recently got a P5 with Di2. The brakes are Magura Hydraulic which are very nice. BUT, in their rush to get this bike out the door, Cervelo launched it without shifters on the bull horns. I kind thought this was one of the main benefits of having Di2 on a TT bike, so I decided to take matters into my own hands.
I bought 2 sets of these Cateye remote buttons for $9 each: http://tinyurl.com/8okd3u3
First thing I did was take out my Di2 battery. Don't know if this is necessary or not, but better safe than sorry.
Then tried for a while to find the "male" connector to tie directly into the Di2 TT wiring kit. After not being able to find them for sale anywhere and not really wanting to put the effort into making my own custom connector, I took out my side snips and simple cut the connector off. There are 4 tiny wires inside the main wire (Red, Black, Green, Blue):
One of the hardest things was actually getting the Di2 Wire out through the bars to the bull horns. It took me at least 15-20 minutes of fiddling with a strong wire to fish it through to act as a snake. The space is very small through the base bars and it is already mostly filled with the hydraulic brake line which doesn't really move at all.
Once I got the snake through it was time to start splicing wires. I know splicing wasn't ideal because I basically can't take my bars off without cutting the work I just did. But I was a bit time constrained and at this point I mostly have my fit dialed in, so I figured it was worth the gamble. If I find some tiny 3 wire connectors, maybe I have a mid-winter project to make this better...
There are 4 Di2 wires and each of the Cateye only has one main wire and a ground. After a bit of research I learned that the blue Di2 wire is not used for TT setups. So for wiring it was Red (from Cateye button) to Red (Di2). White (from other Cateye button) to Black (Di2). Then twist the 2 bare wires (from the Cateye buttons) and attach them to the Green (Di2)
I first slid heat shrink onto the wires, then twisted the wires, then soldered them, then slid the heat-shrink over the bare parts and heated to shrink on for insulation. (This is less important on the green, but still did it when I did the other side.
Then I used heat-shrink on the whole thing.
Then for good measure, I taped it very tightly with electrical tape, then used my torch to melt the tape to hopefully have a nice, tight, waterproof seal.
Now I pulled the wires back into the base bar and creaamed the rest of the rat's nest of wires down inside the bars and remounted the cap.
Next step was to mount the buttons (they simply stick onto the side of the Magura brake levers). The buttons are numbered and with a little trial-and-error, I figured out which one was upshift and which was downshift. I oriented them such that the downshift was the same as they are out at the end of the bars (which I think is on top). Then I retaped my bars and voila, shifters on the bullhorns.
Below is my whole front end setup now. Couple of things I did that are unusual. To have the straw of my Speedfil A2 be in the right spot, I mounted the cage mount facing backwards, but put the bottle in backwards on the cage. I also needed to raise the front of the bottle just a little bit, so I made a spacer (~1cm) out of a small piece of the aerobar extensions that I had cut-off during the fitting. This allows the water to naturally fall to the back where the end of the straw is. I also couldn't find a Garmin mount I liked, so I wook and old aluminum broom stick and cut a few inch section, then used a grinder to hollow out the sides so it fits perfectly against the aero bar extensions. I drilled a couple of holes to keep it snug with a pair of zip ties.
While I'm at it here is my rear bottle holder:
And Jess thought I was CRAZY for putting stickers all over my new bike, but... I figured it was fitting to have the EN stickers near my cranks, because EN helped build the legs that will be turning those cranks. Another interesting note is that the mechanics at my LBS were all geeked out because they said that they did "the impossible". They got my GXP SRM to fit on this P5 (with BBRight bottom bracket). Apparently, a nowmal pressfit GXP adapter will not work on a P5. They had to take apart a couple of different bottom brackets and use the bearings from a Shimano BB on one side and a different set ont he other side. All said and done, my bike is now GXP compatible and holds the SRM great. The ReserveAid stickers are for my Charity team www.reserveaid.org/TeamRA
Summary:
I rode it one time outside for a couple of hours this weekend with these new shifters and what a dream! It was so nice having them right there on the bull horns. It was especially nice if I was coming up to an intersection or when climbing. I found it effortless and much more stable to be able to shift without letting go of the horns. I actually find myself shifting a lot more with the Di2 which allows my cadence to be much more stable.
Comments
John,
I was thinking of gettign Ui2 for my DA4 but I have been waiting for a tt setup from Shimano... I think the aero shifters are due out anytime now, but the brake shifters will be another year. You seem to have found the solution. Where are you soldering the cateye buttons to? I am not sure where you are making the connection to. Is the connection you are making happening to the aero shifter's wires or further down the connections?
Thanks,
Gene
You could do either. They actually shipped the TT wiring harness (by accident) with my bike, so it already had 4 wires coming out of the unit http://www.amazon.com/Shimano-EW-79...B005DTS44M 2 wires were used for the aero bar shifters and the other 2 are made to connect to shifters on the brakes (these were unconnected on my bike and wrapped up inside the bars). If I had bought the Shimano Di2 TT brakes it would have simply been plug-and-play http://www.trisports.com/shimano-di2-tt-brake-shift-lever-set----.html . BUT, that would have cost me $800 instead of $18 AND I would have had to remove my Magura Hydraulic brakes, which I like. If I could have found or made a 3 wire connector, I could have spliced that to the Cateye wires, then simply plugged it into the end of the brake shifter wire. Some people have made this connector: http://fairwheelbikes.com/forum/viewtopic.php?f=6&t=8438&p=101701&hilit=cateye#p101701 I took the easy way out and just spliced into the wire. The Di2 Shifter wire from the harness is long enough to make it all the way out of the hole near the brake. So I pulled the wire all the way through and had about 9 inches or so of wire to work with as I was splicing the wires. Keep in mind that the Cateye wire is also at least 12 inches long. I kept all of this excess wire intact and it's all crammed down inside my base bars just in case I have to cut it someday and redo it (I could probably do it 5-6 times and still have enough wire left over).
It is my understanding that this hack will NOT work with the Ultegra Di2 or on the new DA9000 (11-spd) Di2 that will be out in a few months. Both of those types of Di2 have the "brains" in the shifters, where with the DA7900 (10-spd) Di2 that I have has the "brains" in the deraileurs.
Beautiful! Hack after my own heart as a bit flipping solder junkie. Nice work.
Very nice! I have ZERO skillz when it comes to electrical work, me just don't understand that stuff.
Nice John, I'm an engineer but I still would have been wary to undertake such a mod on my own on such an expensive setup. I find that I usually have to botch a job first or otherwise learn every way on how not to do something before I become very proficient at it.
Other than your freaking awesome bike and shifters, we have a pretty similar setup. I run a Garmin up front of my speedfill A2 on an aerobar bridge and a single bottle mount behind the saddle where I keep my CO2s like yours.
Only quick things I'd add, first might not work with your bar width / stem height at all, but I don't use any bottle cage with my A2 at all up front. It simply sits in between my bars, pushed quite a bit back, and is held in place by two velco straps around the bars. The I put velco on the straw as well (which is much longer than yours) so it folds back and is completely hidden until I 'whip it out' to drink. I really like this setup because in front-on and even side-shot photos of me on the bike you can't even see the A2 or any of the straw, and if you can't see it, I'm betting the wind can't see it either.
Second point, on the rear bottle, I've hear so much conflicting on this I can't even remember anymore. However, for a time I was pretty sure that having the bottle mounted that high was actually a bad thing because it disrupts the smooth airflow coming down your back (hopefully smoothed by your aero helmet) and prevents it from cleanly separating off your ass, to put it scientifically.
Moving the bottle/cage below the saddle will still see the wind of course, but should be in the already turbulent air caused by your legs during the pedal stroke. Or at least that was one theory that was bouncing around.
@Rich- I drink beer when working with wood and building things. These wires were so tiny I felt like I was performing electrical microsurgery. As far as the kids and pets, I did this project right in my living room so I could double it up with dad duty... I took the pics for my own benefit and only after decided to post them here and document it because it was actually easier than I expected. As for Jess, she doesn't know anything about cool stickers (but please don't tell her I said that).
@Trevor- I 'was' an engineer... And it's a bike, not a museum piece. I plan to ride it hard and wanted it exactly how I wanted it. As far as my speedfil placement goes, this bike actually has bosses to mount a traditional cage right in the middle. Putting it on the bars would be way too far forward for me and this way actually puts the straw exactly where I like it. When I'm aero, I think it is fully shielded by my hands. I keep my straw short (with no bite valve) intentionally. When I am not drinking, I rotate it about 90 degrees and it sits either just adobe or just below my arm so it is out of the wind. So when I want to drink, I flip the straw up and bend my neck down just a little bit. Seems to work great for me. As far as the bottle mount goes I always have a full 27oz bottle back there when I'm training because I like the mental edge of training with that little extra bit of weight and knowing it's there if I get stuck some day and need the extra fluids. For race day, I won't have a bottle back there, but will likely tape my spare to the bracket and leave my CO2's on there. I've been around and around on optimal bottle placement in the rear when I was trying to set my P3 up for my last race and even made my own bracket to put it exactly where I wanted it... The bracket I have on the P5 is the one the Cervelo engineers helped design into the bike. It's very cool in that it is a single bar that slides into a hole in the back of the seat post. Their white-paper says they tested it extensively with "foam Dave" in place, so I have to trust that their opinion is better than what I could come up with through my guesswork. Someday when I put a wind tunnel in my basement, I'll test out all kinds of cool configurations. I can just hear Jess now "John, what is that loud humming noise in the basement and why is our electric bill $87,500 this month?"
nice photos, thanks for sharing!