Running cables inside the frame; good/bad?

[EnGut]

Hello all..

Been lurking these forums for some time now and have finally gotten all parts for my e-bike.
I am sorry if this has been brought up before, but a search did not yield any results.

Ok, so while modding my current MTB i thought about running all cables inside the frame. My motivation is being as stealthy as possible, i have a rear hub-motor and a 12ah 36v battery mounted on the handlebar. The motor-, PAS- and rearlight-cable thus have to run along the entire frame and i would love to hide these.

So before i proceed with drilling holes in my frame i would like a little feedback. Would drilling a few holes (5mm diameter) weaken the aluminium frame and what about maintenance, how often do you remove your rear wheel or other wired-up parts? (as these would be much more difficult to remove)

Thanks in advance,
/Dikymon

 

[Ykick]

You're wise to consider these things - even without internal wiring it's a major drag to completely remove the hub motor wheel. And you will need to remove it a few times over the course of time.

For most flat repair I must cut several tie-wraps and remove the wheel enough to work on it laying next to the bike. But, if/when you suffer spoke trouble and/or need more serious wheel work performed the whole thing will need to come off. Internal wiring would entail a lot of rework of your connectors - fishing wire, etc.

Never mind how drilling holes may compromise frame integrity? Not much I would assume but it's unknown territory for a case by case basis?

I suggest dressing wiring cleanly and securely using tie-wraps to start with. Ride the thing for a while. Once you get a feel for how complete removal may or may not be to your situation - design internal routing and employ sensible connector system convenient to the axle wiring.

Flexible loom or even plastic/metal pipe can often disguise external wiring without all of the hassle internal routing would cause. Enjoy the journey!

 

[Drunkskunk]

a 5mm hole in a standard style aluminum bike's down tube will make it a good bit weaker. depending on your riding style and the frame, that may still be acceptable. But were the wire needs to exit on the chainstay at thwe rear, a 5mm hole would seriously weaken the tube.

But your bike design might be something diffrent, in that case it might be great.
A steel frame should be fine, as long as its a mountian bike style, and not designed to be as light as possable.

you can avoid problems with removing the rear wheel by cutting off the connectors and replacing them on a short lead from the motor

 

[LI-ghtcycle]

There are ways people have made very stealthy bikes with out going that route. I think the biggest potential problem you could have is to have the holes you drilled being too sharp and over time vibration cutting into the insulation and shorting the leads.

You can always buy a frame from Oatnet that is designed to have the wires run through it, and they are very reasonable:

Oh shoot, I guess they are sold-out, maybe you can find another one for sale, in fact I think there might still be one available at my LBS that didn't get built up.

Anyhow, I'd recommend you not drill holes especially in an aluminum frame, but if you have a cheap one you can experiment on that you won't feel bad about if it breaks, go for it.

 

[dogman dan]

Some have done it, but really, I can't understand why. With a little bit of creativity, you can make the wires no more obvious than the brake and gear cables.

If you do run wires through the frame, you will want another plug so you can change the tire without pulling out the cables. It should be safe enough on a strong frame, for street use. But on a weak frame, or off road riding, I wouldn't drill any holes.

 

[johnrobholmes]

While on the subject, has anybody considered the interaction that could happen when running power leads inside a frame? I would assume no induction or interaction within the metal with the main power wires since the current flow is DC and the metal is not between the two wires, but three phase power wires for motors could present an eddy current issue unless braided, correct? I would also assume it wise to twist the main power wires as well.


Any thoughts on this?

 

[Drunkskunk]

While on the subject, has anybody considered the interaction that could happen when running power leads inside a frame? I would assume no induction or interaction within the metal with the main power wires since the current flow is DC and the metal is not between the two wires, but three phase power wires for motors could present an eddy current issue unless braided, correct? I would also assume it wise to twist the main power wires as well.

Any thoughts on this?

Realy no diffrent than running AC 110v power through metal conduit at your office or in your work shop. Any eddy currents would realy only affect high speed data lines that ran also inside the tube. the power lost would be in picowatts.