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di2 build with complications

 I need advise on  a project I have, my dedline for when the project starts is newyears. I have a trek 2100zr. If your not fimiliar with it, it is an aluminum bike with carbon seat stays and fork. I intend to replace its mix of 9, 10, and even 11 speed mismatched components, with dura ace 9070 groupset(Ive opted for 9070 insted of 9150 for astedic reasons). I want to use the internal battery instead of the external batter. but my bike has no internal cable routing, since I already bought the parts I am just going to make it work. I have no fear of voiding the warenty, because ive already doen that after getting a braze on mount welded on to the frame because at the time I was  unawear that there was an adapter. I am not afraid to dril the frame, I know a guy who works at a machine shop and is willing to help me drill the holes. I want to finde a method that hides the cables fairly wel and puts the battery in the frame and uses my jc41 junction, because I am not interested in buying a jc40.I can 3d print simple parts to alow me to achive this goal. 

reguirements:

I need full drive train functionality

battery to be mounted internaly

I cant buy any new components because my money is wrped up in raxce entrys for 2020

no holes in the carbon seat stays

no modification to the components other than heatshrink

it NEEDS to be water proof because I ride in the rain alot

goals:

minimal holes

clean look

aero

I would prefer to avoid removing the bb(rather drill an extra hole that remove the bb, unles it means no holes in my frame)

ive thouht about puting the junction b on my chai stay and routing the di2 cable throught that hole in my chain stay to the battery, If that will work, that would be my prefered option,

thanks in advance for any help that I can get!

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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18 comments

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mak parshall | 4 years ago
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same key again, just another way I thought up

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mak parshall | 4 years ago
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this Is the other way of routing the cbles that I thought up. with this one, I use cable ties to rout the cable down the down tube and onto the chaintay, where it connects the the junction b. from the junction b, the battery cable routs therought the hole at the end of the chain stay over the bottome beraket to the battery, NO DRILLING INVOLVED! (key is the same as my previus drawing)

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mak parshall | 4 years ago
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Ok thanks for all of your help! Ill post pictures when I complete the biuld

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mak parshall | 4 years ago
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this Is kind of what I'm thinking, would this work? its prety much what ive heard. Ive anotated a picture of my bike from 7 months ago, before I canged the bartape and heaset and slammed my stem.

key :

red- internal cables

green- external cables

blue- juncrions

brown- deraliures

 

Avatar
CXR94Di2 replied to mak parshall | 4 years ago
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mak parshall wrote:

this Is kind of what I'm thinking, would this work? its prety much what ive heard. Ive anotated a picture of my bike from 7 months ago, before I canged the bartape and heaset and slammed my stem.

key :

red- internal cables

green- external cables

blue- juncrions

brown- deraliures

 

That looks right.

Don't worry about battery, it weighs very little, much less than a bottle of water. It will not effect centre of gravity to the point you can feel it.

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mak parshall | 4 years ago
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it there a way to lower my batterys position to lower my center of gravity? like some how in the downtube or right on top of the bottom bracket?

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mak parshall | 4 years ago
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ok, thanks this helps a lot! 

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mak parshall | 4 years ago
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ok that seems like would work, how would It affect my bikes structural integrity ? (drilling holes in the frame)

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CXR94Di2 replied to mak parshall | 4 years ago
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mak parshall wrote:

ok that seems like would work, how would It affect my bikes structural integrity ? (drilling holes in the frame)

The big downtube from steering head, no problems, same for seat tube near derailleur.
The one in the chain stay are usually around 50mm from the weld where the axle is. I would drill the smallest hole that allows the Di2 connector through, then with needle file smooth the hole edges to relieve stress fracture risk.

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CXR94Di2 | 4 years ago
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If the chain stays are aluminium and the seat stays carbon, then with only 3 holes you can fit the Di2 system.

Hole placement
1 near the steering on the side of the downtube.

2 Near the bottom of the seat tube to allow for front derailleur.

3 Top of chain stay near the wheel axle point.

Look at a several images(Google) of the cable access points on several bikes to get an idea of position.

You will need to remove bottom bracket, but its no big deal. Even get local bike shop to remove and refit after you have wired up the frame.

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mak parshall | 4 years ago
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would caulking (Its waterproof and ussed to seal up stuff) its sort of like apoxy but softer, would it work to use it to replace the gromets?

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hawkinspeter replied to mak parshall | 4 years ago
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mak parshall wrote:

would caulking (Its waterproof and ussed to seal up stuff) its sort of like apoxy but softer, would it work to use it to replace the gromets?

Possibly. I've used Sugru on my bike when the hard plastic hose holder kept breaking. Sugru is hand moldable silicone rubber - it sets in about half an hour. You can get it from Amazon/EBay or model shops easily enough in a variety of colours.

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mak parshall | 4 years ago
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would my jc41 be ok outside of my frame? would I need to cover it In heat shrink?

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mak parshall | 4 years ago
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thanks for your advice, I'll think it over. 

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mak parshall | 4 years ago
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by the way, thanks for your advice! what size holes should I use? and can I make my own gromets to avoid buying brand new ones?

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mak parshall | 4 years ago
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the cabling dosent need to be internal, just the battery. I am wondering if I can rout the cable through the hole that is just above the rear mech to the battery. Id there Is a better way, Id love to know it.

Avatar
kil0ran replied to mak parshall | 4 years ago
1 like

mak parshall wrote:

the cabling dosent need to be internal, just the battery. I am wondering if I can rout the cable through the hole that is just above the rear mech to the battery. Id there Is a better way, Id love to know it.

That might work, but you'll probably need to make it bigger because annoyingly Di2 cable ends are thicker than standard gear cable outers. I know this because I'd hoped to use my old cable stops when I did an external wire Di2 install on my bike. Hole needs to be at least 6mm diameter.

If you're handy with a soldering iron/electronics fettling it might be possible to cut the terminal off the cable, feed it through the chainstay and then reconnect it but you risk destroying an expensive cable in the process.

Grommets will just need to be big enough to accommodate the main part of the Di2 cable. Probably easier to buy them - e.g. https://www.ribblecycles.co.uk/shimano-ultegra-di2-grommet-pack-of-4/

Looks like frame holes need to be 6mm to take off-the-shelf grommets...

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kil0ran | 4 years ago
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Well the easiest and cheapest option is to stick with external cable routing and use the SM-BTC1 battery case that sits under your bottle cage mount (that also replaces the JC41). For internal routing the BB will have to come out.

You say no holes in your chainstays. If that's an absolute requirement then you're going to need to have the rear mech cable exiting from the BB.

If you're absolutely set on internal wiring then I would do the following:

Hole at top of down tube to take the wires from the shifters/Junction A

Hole in front of seat tube for the front mech cable

Hole in base of BB - you can potentially just widen whatever is already there for the BB cable guide for the rear mech cable. And then run the rear mech cable along the bottom of the chainstay

Place the JC41 in the seat tube above the BB. I assume you've got the necessary adapter to fit the battery inside your seatpost.

If you do the above everything is then internal bar the rear mech cable which will need to be cable-tied to the driveside chainstay.

All Di2 kit is inherently waterproof so no need to worry about that. You will need to make/buy grommets for the frame holes to minimise any chafing and stop water getting inside your frame.

Remember - it has to wired as follows

Shifters -> Junction A -> Junction B and then split out to the mechs and the battery.

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