keg61

the fine print first... I am not nor do I pretend to be, any kind of engineer or electrician. I've been thinking that using the kind of copper tape easily obtained from Amazon on the underside of a fender would be better than trying to tape wires in place for a dyno powered, fender mounted tailight. Is this practical? I assume if it is some of y'all have already done it...

mulveyr 

If you don't want to run dynamo wiring under the fender's edge roll ( or if you're using plastic fenders. there isn't a roll ), then by far the easiest thing to do is pick up a roll of 2" aluminum tape from your favorite retailer.

Then just run the wire inside the fender and tape it down; the tape is there just for adhesion, not conductivity. Aluminum tape will stick there until the end of time regardless of rain, snow, or sand.

Secret Squirrel

Copper tape would be fine if you could protect the copper from the elements. copper is very susceptable to corrosion.

steelbikeguy

copper tape is a conductor, and will normally allow you to easily solder a wire to it.

Of course, wire is also a conductor. I'm not sure I see a reason to favor copper tape over wire. The apparent reason would be that copper tape has adhesive on it, but... is there any reason to think that this adhesive would last under the nasty conditions found inside of a fender?

If memory serves, the photos of successful(?) installations of wires/conductors in a fender usually involve running the wire inside of the rolled edge of an aluminum fender.

It's an interesting problem, though. Sounds like a good excuse to scour the catalogs for waterproof/salt-proof/crud-proof adhesives. After you find a few good candidates, carefully clean & prep the surface of the fender, glue up a few wires and strips of copper tape inside of your fender and run it for a few years. Check on them every few months to see how they are doing, take a few photos, and generally take good notes.

Personally, I use a rear rack on my dynamo-equipped bikes, so I just run the wires along the rack. Without a rack.. I've seen photos where the wire was run along a chainstay and then up one of the fender struts/stays.


good luck!

Steve in Peoria

keg61

Thanks guys, I didn't think at all about the corrosion.If it was just the solder points I could cover it with liquid electrical tape but it'd be wasteful to paint over the full length of the tape. My fenders are plastic(polycarbonate) so there is no edge roll for routing wires. I will be mounting a rack above the fender and will probably go ahead and use a strut on it to route my wires. I liked the "wow that's clever" reaction I was envisioning from my friends who don't know any better when I showed them the wire to tape to wire to light routing, but I think just using wire is smarter. thanks for your input.

steelbikeguy

Since you will be using non-conductive fenders, you might think about putting the adhesive copper (or aluminum) tape on the outer surface of the fenders! Just be sure to solder the wires at each end *before* you put the tape on the fender, though.

Copper tape would gradually oxidize... probably the same way that pennies do. The aluminum tape would just get a bit dull and wouldn't change much in appearance.

I'm still not sure how the adhesive would fare, but it's got to be a more benign environment than inside the fender.

Either way... it's fun to think about new & creative ways to do stuff like this. Have fun!


Steve in Peoria

CliffordK

If your copper tape is bare on top, it should eventually generate a nice greenish-bronze patina, although sometimes it will go green.

You will need two conductors, positive + negative. For steel, the negative is usually through the frame and components. Carbon Fiber might also be conductive provided you get a good bond to the base material.

You could even laminate a layer of Carbon Fiber to your fender

An issue, of course, would be insulating your conductor. Not a big problem with a plastic fender, but it could become an issue with other materials.

01 CAt Man Do

....flat speaker wire with adhesive backing....then maybe some electrical tape over that for some extra insurance...

keg61

I was thinking about it last night and I'm considering going ahead with the copper tape on the underside of the fender afterall, then cover it with black gorilla tape( my brother says gorilla tape will stick forever even in crappy Pennsylvania winters)and liquid electrical tape and redo it(the copper tape is fairly cheap) as often as needed to combat corrosion(possibly as often as every spring)

keg61

I really need to think more before posting replies I might go with the copper tape on top of the fender idea, thanks steelbikeguy the bike frame is green, fender is black, so the copper color is a decent contrast and if it tarnishes a nice green it'd look ok, if not it is in the open and accessible for repair/replacement

DiegoFrogs

I used aluminum 'duct' tape that's used in actual ducts to run my 2-conductor wire under my plastic PB fender. It held up great for the four years I've been using it, even riding in gravel a bit with knobby tires.

I just mounted my lamp very close to the lower stays by drilling two small holes to mount the lamp, and another for the wire to come through the fender. B&M says not to mount it on plastic fenders, but I'm not the type that listens to authority.