Di2 upgrade and frame modification

Discuss light weight issues concerning road bikes & parts.
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naylor343
Posts: 111
Joined: Sat Aug 30, 2008 1:46 pm
Location: Ariege, Midi-Pyrenees

by naylor343

OK, it's time to upgrade to Di2. The trusty 7800 group has served well, I resisted 7900 and waited, but now the rear gear selection is getting a little tired, so maybe time to retire it. It came down to a choice of 9000 or 6870 and the Di2 option appeals.

I have a 2009 TCR Adv SL so can easily accommodate an internal battery and a mostly internal wiring setup, but in the frames current state, I would need to run the rear mech cable external, and this would look OK, especially as the frame is black.

I am considering modifying the frame for a full internal fit. To do this I would need to drill one hole in the rear drop out and enlarge the front mech cable drilling. On the 2009 model the rear drop outs are aluminium bonded into the tubes. The front mech is easy as the under BB hole is plenty big enough, it is just a case of enlarging the existing drilling on the upper BB area with a fine circular file.

I have attached photos showing where the cable exits the frame in its current configuration, where the hole would need to be drilled, and an example of how the original Di2 only frames from giant were drilled (this is what I want to achieve). Basically, the original TCR Di2 only frames were exactly the same in the rear except for this one hole in the rear drop out.

Secondly I am considering removing the existing cable stops that are riveted onto the frame tubes. I 'think' that this could be done quite cleanly as I can pass a piece of paper between the stop outer edge and the tube, so it appears that the frame clear coat was applied before the stops were fitted, however, the unknown is whether the stops are both riveted and bonded to the frame. I am worried that if I drill the rivet heads out that the stops still don't budge. If they were bonded then removal could be a bit messy.

The frame is well out of warranty and re-sale is not a concern. So, I would like to here from anyone out there who has attempted similar or who is a bit of a frame structural expert.

Photos are here: https://onedrive.live.com/?cid=CE461544A39EEF41&id=CE461544A39EEF41%21473

Thanks in advance for any info/advice.

by Weenie


glepore
Posts: 983
Joined: Thu Mar 28, 2013 4:42 pm
Location: Pa USA

by glepore

Why not just drill the stops as needed (both front and at the rear mech)?
Cysco Ti custom Campy SR mechanical (6.9);Cannondale SS Evo Di2 7970 (5.79); Willier Cento Uno Air Di2 9070 (7.0); C40 Mk2 DA 7800 ; Anvil Custom steel Etap;1996 Colnago Technos Record

11.4
Posts: 1097
Joined: Tue May 23, 2006 4:33 am

by 11.4

Before you get too far, check your bottom bracket. You need holes big enough to fit hardware, including the junction box, and it all has to fit around the bottom bracket. The bottom bracket can block the hole to the right chain stay.

As for the stops, they are typically not bonded. Even if they are, you can refinish that small area and make it look good, especially since the stops aren't right up on the top of tubes in plain view. Definitely go full-internal. There are two versions of the little Shimano grommets, one for oval holes (which work a bit more easily) and one for round ones. You can use a rattail file to shape a hole for the oval holes, but either version will work.

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naylor343
Posts: 111
Joined: Sat Aug 30, 2008 1:46 pm
Location: Ariege, Midi-Pyrenees

by naylor343

Thanks for the reply :D No problem with the rest of the frame, it was designed to take the harness for the wired SRM. There is a hole under the TT for the cable entry then the harness passes through the head tube, then down tube, to the BB. The oversized down tube is fully open and easily accessed through the head tube to feed in the internal junction box. The BB axel area is sealed, but the tube area around is is super oversized and cables can pass upto the seat pin area and to the chain stays. I will run wire through to the head tube from the seat stays and seatpin and then pull the whole harness through already connected to the junction box.

The only question remaining now is wether to drill the drop our for the rear mech cable, or not?
Really looking for some expert advice on this one. Part of me thinks that this is all that giant did to the early di2 only frames, but at the same time I am mindful that they could have had a specially strengthened drop out for this frame.

My current thinking is that it is less of a risk drilling the aluminum, than drilling a hole or enlarging the cable stop holes in the carbon chain stay.

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naylor343
Posts: 111
Joined: Sat Aug 30, 2008 1:46 pm
Location: Ariege, Midi-Pyrenees

by naylor343

I've been reading the 6870 workshop manual and read that the wiring should only be pulled through frame from the extrematies towards the BB area. I will need to connect all 4 cables to the internal junction box and feed it from the head tube using guide wires to help it through.

Is this going to be a problem? I cannot see why myself, but would like to be sure.

Still after any advice on drilling the rear drop out.

Thanks for reading.

afalts
Posts: 157
Joined: Thu Mar 08, 2012 3:20 pm

by afalts

naylor343 wrote:The frame is well out of warranty.


Just a little fyi, Giant has a lifetime warranty on their frames, unless you have already done something to render the warranty useless.

Regardless, I would still do the modifications 8)

Butcher
Shop Owner
Posts: 821
Joined: Sun Jan 03, 2010 4:58 am

by Butcher

I've done both. Although it was a SW Tarmac frame, I did not have a problem with either one.

The rear dropout on the SL3 is hollow and after researching pictures of it, it was a no brainer to drill it there. The main reason was the visual appeal. The older Tarmac frame was drilled where the rear cable stop was.

If you indeed drill out the rivets for the cable stops, a 1/8" carbon fiber rod [and epoxy] works well to plug the hole. The cable stops did not appear to be glued, just riveted.

BTW, I installed a EPS system, not Di2.

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naylor343
Posts: 111
Joined: Sat Aug 30, 2008 1:46 pm
Location: Ariege, Midi-Pyrenees

by naylor343

Afalts, I did not know that, is that life time any owner or just the original owner?

Butcher, thanks for your info, that is what I really wanted to here :-). The TCR dropouts are kind of hollow too, in that they comprise of 3 reinforced ribs with hollow sections in between that have been filled in, so in effect I m drilling into the infill section.

by Weenie


afalts
Posts: 157
Joined: Thu Mar 08, 2012 3:20 pm

by afalts

Just the original owner. Also, they won't warranty a warranty frame; at least not Giant Canada.

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