# Roubaix SL3/Di2 Custom Build



## diablo2112 (Nov 7, 2007)

Here's a few pics of my just-finished build. 2011 Specialized SL3 Roubaix. Full Shimano Di2, Shimano Pro bar.

I have a thing for wires and zip ties, so spent a bit of time hiding everything on this build. Cut the Di2 harness and routed through the frame. A few other goodies included disassembling the Di2 battery and re-working it into the seat post (retains stock battery connector for charging). I added an auxillary shift switch, which I also disassembled to custom mount onto the bars with no wires.

Finally, I shipped in the new SC7900 flightdeck computer (from Japan), which integrates many Di2 functions. This eliminates the unsightly front-wire harness, which zip-tied to the brake cables. I have a bit of experience setting up the new SC7900 computer, and it wasn't easy. I can understand why Shimano has not yet released this in the US. I'm still waiting on the Shimano Pro computer mount (which integrates with the Pro Evo bars); the mount in the pics below is temporary.

I ride in the mountains of northern New Mexico. Went with a 34/50 compact and 11-28 cassette. Cassette works just fine with the Di2 system (as others have found).

Final weight, all-up is 16# 11oz. Snow on the ground, so no ride-time yet. 

Enjoy.


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## ukbloke (Sep 1, 2007)

Nice work with the install! Bike manufacturers need to get fully on board with Di2 integration for the rest of us without your battery and cable hiding skills.

So what do you think of Specialized's internal cable routing on the Roubaix? Is it well executed? How hard was it to fish the cables through?


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## Hairy Legs (Sep 19, 2006)

Wow! That is a very clean set up! I love your attention to detail. Nice work!


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## diablo2112 (Nov 7, 2007)

Regarding cable routing on the Roubaix SL3. The basic engineering and layout is excellent, especially the rear derauiller exit. Routing was tricky, however, not something for a beginner. The problem is the bottom bracket mount is sealed (and oversized). cables are inserted and have to go around the mount. The only way to do this is gravity. So, I used a very good bike stand which would position the frame at any position, inserted old shift cables with the heavy end first, then used long forceps to retrieve the cable end through the opening in the downtube (see pic, above). Specialized does supply an instruction sheet for this, with the same procedure.

Overall, not an easy job. Specialized did ship the SL3 with guide tubes, but these aren't appropriate for the Di2 routing, as they exit at different points on the frame.


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## KonaSS (Aug 18, 2006)

*I like it!*

The 1990's called......they want their splash cork bar tape back. 

Just kidding (sorta) - very nice bike.


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## diablo2112 (Nov 7, 2007)

Yeah, the tape needs changed. It's what I had in my shop. I have white and orange on order.


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## Special Eyes (Feb 2, 2011)

What a looker! Bout time we saw some serious Roubiax's around here.

Is that a heated seat you've got there?


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## Special Eyes (Feb 2, 2011)

system duplication?????


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## Special Eyes (Feb 2, 2011)

where's the delete button??


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## roadie01 (Apr 13, 2010)

An old trick we used to use to fish computer cables through frames (back in the day of steel) was to take a string or thread and suck it through to the location in the frame desired. Then you simply pull the wire through the frame. Of course forgetting to tape the vent holes would lead to some frustration and WTF momments. This was an especially clean way to mount the old Avocet computers with the ring sensor mounted down at the hub.


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## diablo2112 (Nov 7, 2007)

Using vacuum to suck light string is just an awesome idea, thanks for posting this! Very clever, I'll remember that for tricky routes.


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## billysan (Apr 30, 2010)

Hi,

I would send a pm but I dont have a high enough post count apparently!

Ive been trying to answer a question I have regarding programming an SC-7900 flightdeck unit, and on my web trawl I found this post about your roubaix build. Very nice bike, but I digress.

I've been offered a second hand SC-7900 for decent money, so am tempted to give it a go. Im unsure whether I can get it to work on my bike however. Reason being a little subtle.

I run a custom 13-28 cassette on my bike 
(13,14,15,16,17,18,19,21,24,28), this combination was never sold by shimano. Reading the SC-7900 instructions it sounds like you can only choose from certain cassette conbinations, ie the normal ones. You can however change individual chainring sizes.

Can you remember, or would you be able to tell if in the setup menu you can indeed programme each individual sprocket size, or whether you just have the option of the 8 cassette combinations offered at 7900 level?

As the unit calculates cadence from the wheel speed and gearing, I dont want to end up with inaccurate cadence readings.

Thanks in advance.


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## [email protected] (Jan 15, 2010)

Perfect bike....clean DI2 setup (great battery solution)...I love it!!!!!!!


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## roadworthy (Nov 11, 2011)

Fellow SL3 Roubaix owner albeit without Di2. Fantastic build...great attention to detail.
Can you explain where and why you installed an aux. shift switch?
Also..basic question about Di2...is shifting identical to DuraAce, i.e. is the brake lever used for shifting?
Congrats!


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## diablo2112 (Nov 7, 2007)

1) Regarding custom cassettes on the SC7900. You're correct, as far as I've been able to determine, it only supports the stock Shimano cassettes. I, too, have a custom 11-32 cassette, and I've not found a way to enter individual ratios.

2) Aux switch is mounted with tiny screws carefully (and properly) tapped into the bar. I had to disassemble the switch, mount the housing, then reassemble the switch while mounted. Pictures show the result.

3) DI2 shifting from the brake levers is nearly identical. You sweep a larger lever mounted inside the brake lever inward to downshift; you sweep a smaller lever mounted inside the larger lever for the upshift.


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## roadworthy (Nov 11, 2011)

diablo2112 said:


> 1) Regarding custom cassettes on the SC7900. You're correct, as far as I've been able to determine, it only supports the stock Shimano cassettes. I, too, have a custom 11-32 cassette, and I've not found a way to enter individual ratios.
> 
> 2) Aux switch is mounted with tiny screws carefully (and properly) tapped into the bar. I had to disassemble the switch, mount the housing, then reassemble the switch while mounted. Pictures show the result.
> 
> 3) DI2 shifting from the brake levers is nearly identical. You sweep a larger lever mounted inside the brake lever inward to downshift; you sweep a smaller lever mounted inside the larger lever for the upshift.


The Aux switch is a very cool touch. Must be sweet to use...don't even have to reach to the hoods to shift...thumb push right from the tops.
Do you have the Aux switch only for the right aka rear cassette shifting? If so, would there be any utility to put another Aux switch on the other side for the front derailleur or do you believe this is overkill?
Thanks.
PS: did you have to do any drilling...or are all the ports on the SL3 Roubaix already there to internally route the Di2?


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## msg98 (Oct 27, 2011)

what's the shimano switch by the stem? 
thx


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## roadworthy (Nov 11, 2011)

msg98 said:


> what's the shimano switch by the stem?
> thx


Thats the Aux shifting switch. You can shift the rear derailleur from the handlebar tops...pretty cool.


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## CEARACING (Sep 5, 2011)

diablo2112 said:


> Here's a few pics of my just-finished build. 2011 Specialized SL3 Roubaix. Full Shimano Di2, Shimano Pro bar.
> 
> I have a thing for wires and zip ties, so spent a bit of time hiding everything on this build. Cut the Di2 harness and routed through the frame. A few other goodies included disassembling the Di2 battery and re-working it into the seat post (retains stock battery connector for charging). I added an auxillary shift switch, which I also disassembled to custom mount onto the bars with no wires.
> 
> ...


What Bar Tape is that???, it´s nice


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