Originally Posted by
wahoonc
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

Originally Posted by
Hairy Hands
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
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: