Which e-tubes to buy?

Discuss light weight issues concerning road bikes & parts.
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showdown
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Joined: Fri Sep 17, 2010 4:48 pm

by showdown

Heya,

I'm in the process of gathering all the necessary bits and pieces for my next build- a Colnago C59 Dura-Ace Di2.

Does anyone have any insight into what lengths of e-tube I'll need? I suppose I could just order up a whole bunch but I'd rather be a bit more precise as they're each nearly $40.

Thanks in advance.

-J

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rmerka
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Location: Austin, TX

by rmerka

When I was in the same boat as you as to what lengths of wire to get for my R5 build, I ran string to all the termination points to simulate the wires and then measured the strings. If it's borderline go a little longer.

by Weenie


Crampandgoslo
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by Crampandgoslo

What's the size of the bike you'll be building up?

These guys have them for less than $30 if you want to try a few sizes

http://www.artscyclery.com/Shimano_SD50 ... b=RDMCOMPS

AndreLM
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Joined: Tue Feb 05, 2013 11:53 pm

by AndreLM

Competitive Cyclist has a nice table with the suggested sizes:
http://www.competitivecyclist.com/shima ... F0MTAwMTA5

11.4
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by 11.4

That Competitive Cyclist chart is pretty good.

Basically, unless you're riding very wide bars or have a very tall bike, 350 mm cables work for each shift lever, the rear derailleur, and the front derailleur. 750 mm cables work for an internal seat post battery and for the down tube connection. I fix the junction box under the front of the stem -- it tends to be a messy install if it's on a brake cable or anywhere else.

Be sure to leave a little loop of cable (taking up a couple centimeters or so) at each lever so that if anything gets knocked in a fall, it doesn't pull the cable out of the lever socket. Generally try to have the brake cable shield the e-tube cable from hits -- the rubber insulation isn't all that tough and can be crushed, at which point the system can start to act erratically. Tape everything down along the bars -- don't count on the handlebar tape to keep it in place. And I got some heat-shrinkable tubing (Home Depot had 7-foot rolls of the stuff in the right size), which you can use both just to protect the cables as they go in and out of frame holes. Also, you can slip sections over the rear brake housing (and perhaps elsewhere) and run the e-tube inside so the two cables are sandwiched together. A little hair dryer action and the tubing tightens up neatly over both parts.

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coloclimber
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by coloclimber

11.4 wrote: And I got some heat-shrinkable tubing (Home Depot had 7-foot rolls of the stuff in the right size), which you can use both just to protect the cables as they go in and out of frame holes. Also, you can slip sections over the rear brake housing (and perhaps elsewhere) and run the e-tube inside so the two cables are sandwiched together. A little hair dryer action and the tubing tightens up neatly over both parts.


Great tip and idea!
-Deacon Doctor Colorado Slim

petal666
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by petal666

11.4 wrote: Also, you can slip sections over the rear brake housing (and perhaps elsewhere) and run the e-tube inside so the two cables are sandwiched together. A little hair dryer action and the tubing tightens up neatly over both parts.
Nice tip.

vwo05
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Joined: Sun Oct 07, 2012 7:39 pm

by vwo05

Here is the Shimano guide on how to measure for e-tube wire lengths.

Image

by Weenie


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LeviR
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by LeviR

That is a nice guide. Just to make sure, I would mock up a piece of rope and measure it to make sure. That's what I did with my Cervelo R5.

vwo05 wrote:Here is the Shimano guide on how to measure for e-tube wire lengths.

Image

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