Di2 seatpost/battery modification

Discuss light weight issues concerning road bikes & parts.
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cyman
Posts: 77
Joined: Tue Jun 10, 2008 3:25 pm

by cyman

I have now completed installing the internal wiring for the Di2 system. The frameset is a deddachia scuro which had campag record gears. All the gear bosses fitted to the frame had to be removed, all the holes apart from one was filled using epoxy, then repainted.
The battery conversion was fairly simple, but this being the first one i have done i was working in the dark regarding the battery module itself. This conversion would suit most seat posts.
I will go into more detail when i load up the photo's.

by Weenie


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CharlesM
Posts: 5771
Joined: Tue Sep 26, 2006 12:37 am
Location: Phoenix Arizona

by CharlesM

sounds like it will look super clean but purely on a performance base isnt it better to have the battery low on the frame?

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cyman
Posts: 77
Joined: Tue Jun 10, 2008 3:25 pm

by cyman

I agree that it would be better to have a lower centre of gravity, but would you really notice 50gramms ?

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stella-azzurra
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Joined: Mon Jan 23, 2006 6:35 am
Location: New York

by stella-azzurra

Most likely no. And wouldn't a seat bag filled with stuff be heavier?
I never took drugs to improve my performance at any time. I will be willing to stick my finger into a polygraph test if anyone with big media pull wants to take issue. If you buy a signed poster now it will not be tarnished later. --Graeme Obree


merkyworks
Posts: 188
Joined: Tue Jan 27, 2009 1:31 am

by merkyworks

its was Columbia on the plasma 3 in the giro this past year that got it started if i remember correctly

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cyman
Posts: 77
Joined: Tue Jun 10, 2008 3:25 pm

by cyman

At least with this mod it gets rid of the bulky looking battery holder and its location.
All the parts are still used with the addition of 1 switch, 1 male & female connector and some extra wires. and a bit of heat shrink.

RichTheRoadie
Tinker, Taylor, Tart
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Joined: Sat Nov 29, 2008 8:00 pm
Location: Sydney, Aus.

by RichTheRoadie

New Madone mounts it under the BB - tidiest place whilst still being easily accessible I reckon

foz
Posts: 151
Joined: Mon Sep 08, 2008 3:37 pm

by foz

This sounds interesting - post some photos! I've never tried Di2, and doubt I will for a while. But I like 'clean' looking bikes, so the internal routing should help clean things up a bit. If 50g is all the battery weighs then it won't affect the ride at all, wherever it is. Think how much a heavier saddle changes the ride over a lighter one - nothing at all (except in the comfort department!)

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cyman
Posts: 77
Joined: Tue Jun 10, 2008 3:25 pm

by cyman

Ok, here is a small update. I have loaded them on photobucket which makes my life easier. Some things still need to be made better.
will give more details later. Let the pictures do the talking.
http://s277.photobucket.com/albums/kk44/zyman2464/

Geoff
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Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

If I am following your photos correctly, you: disassembled the battery case and wiring; replaced the wires with a longer, home-made harness; added an on/off switch behind the bottom bracket; re-routed all the power through the seatpost and seat tube; and, mounted the battery under the saddle. Is that correct? Did you use the stock battery case again? Can you provide us some photos of the under-saddle mounting?

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cyman
Posts: 77
Joined: Tue Jun 10, 2008 3:25 pm

by cyman

I removed the battery from it's case and enclosed it with adhesive waterproof heatshrink. see photo 10, it is inserted into the seatpost, then held in place with some silicone sealer so that it would be easy to remove if i ever needed to. It is recharged via the 3 way socket embeded in the seatpost. The original battery case is then used with the shimano charger to charge the battery as normal. I will take some more photo's showing this. I discharged the battery and recharged it using this modification to check the charging function.

jz4nyc
Posts: 663
Joined: Sat Aug 30, 2008 7:07 am

by jz4nyc

any structural concerns about drilling a hole in the seatpost like that?

that's some serious handiwork. very clean setup. kudos! :thumbup:

Geoff
Posts: 5093
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

That is among the best work, of any kind, that I have seen to-date.

It would be great to try to do something similar with an integrated bike with the battery at the junction of the seatmast and the bottom bracket and the recharger out the top of the seatmast under the saddle...

maxxevv
Posts: 1952
Joined: Wed Feb 09, 2005 4:51 am

by maxxevv

woww... great stuff!

Just wondering though, where did you get the wire grommets from?

Image

Thanks! :thumbup:

by Weenie


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