So I recently bought this 1984 Miyata Terra Runner, which besides needing a new FW, chain, and some cables and tubes, is in outstanding shape. Just hauled the BB out, and the grease is just like the day it came out of the factory.



However it came from a German lady, I'm pretty sure they bought it in Germany, as the brakes were reversed (right was front), Suntour thumbies mounted to stem, reflectors look upside down, and it is equipped with a swiss made bottle dynamo and german lights. Anyway, I'm striping it down now for a rebuild and cleaning. Swapping out the crappy RD and thumbies for nicer/newer Suntour XC Pro stuff from early 90's (NOS). The PO had the wire for the front light zip tied and taped to the DT and then hot glued along the inside of the rear fender. Same for the rear, hot glued all the way down the rear fender.

I'm wondering, is there a better way to do this? Is it blasphemy to consider drilling tiny holes in the frame for cable routing?

Explain to me how you've routed your lighting systems!

I'm also thinking about swapping out the bulbs for some of these https://www.reflectalite.com/LEDpage.html. I saw something on here a while back about LED conversions, this seems to be a much easier way to go about getting more bang for your buck from a bottle generator. Anyone use these before?

You used to be able to get 'w' shaped pieces of thin spring wire that slid inside the fender and kept the wire in place. I'm sure those are basically unobtainable now. If you want a clean run for the wire on the rest of the bike, you can use a shot of compressed air to blow the wire down a length of brake housing, and secure it to the down tube with a set of brake cable clamps. It looks like it belongs and helps keep everything in place.

I've had good luck drilling holes in the frame to route dynamo wiring internally, but only when the frame was slated for a repaint afterward. Otherwise, you risk rust starting from the freshly exposed steel. Also, unless done properly, internal wiring can cause more headaches than it's worth. An easier and very reliable alternative method is to glue some wire guides along the downtube and wherever else you want the wiring secured externally. What I did on one bike was to use 1" lengths of narrow shrink tubing. I glued them along the downtube and ran the wiring through them. I think I used three on the downtube. I didn't bother to heat shrink them, they just happened to be the right diameter I was looking for. Heck, you could cut up a plastic drinking straw and get the same result. Here are some pics:

Closeup:


You can barely tell there's wire there:


For the adhesive, I used Automotive Goop. I use it for just about everything. I've commuted with this setup all winter and spring and it hasn't failed me yet.

Just get some dia compe 28.6 (assuming thats the downtube diameter) cable clamps.
Run the wire(s) under the fenders inside the edge roll...or epoxy. Or stainless steel zip-ties along the frame.

To stick wiring to the inside of a fender I have laid the wire in place against the rolled edge and put dabs of sealant/caulking to hold it in place. For wiring down the frame I will quite often zip tie it to an existing cable housing, though I do like southpaw Boston's idea of using a small piece of tubing for a cable guide.

Aaron

Lots of the long distance guys that have fenders will route the wires under the fender along the rolled edge. Then get a 2 part epoxy and totally encase the entire length of wire in epoxy. It will never come loose causing a potential accident plus it's fully waterproof. On the frame or fork you can get tie wraps that have a built in loop of different wire gauges that will hold the wire in place nicely. Look at online electrical supply houses

Two of my bikes are wired for lights. The tandem had loops and such underneath along with the brake and derailleur cables. (With three brakes plus lights, it has about 16 miles of cabling or wiring.) On my other bike I routed the front along the exposed rear brake cable. It looks purposeful and not much more cluttered than the original configuration.

This is what I did to two of my dynamo bikes! I use the same Automotive goop that I linked to above. Wiring is completely encased in it, it's beyond permanent (which can be both good and bad). Be sure if you do this that you use rubber or plastic grommets wherever the wiring enters and exits holes in the fender or frame:

For a considerably less permanent rear fender option, you can secure your wire to a piece of spring steel with little pieces of heat shrink tubing every few inches and mount that under the fender. You have to bend hooks or eyelets into both ends of the spring, which is tricky since spring steel doesn't take bends very well. Get it right the first time and you'll be okay; try to bend it a second time, and it will probably break. If you need two wires, the spring can probably serve as one of them. You will find a piece of spring steel, much longer than you need, in the bead of an old tire.