A few guys from another thread asked about this, so I figured I'd make a new topic rather than derail that thread. Forgive the small thumbnails, my photobucket isn't working right.

I wanted to try mounting my battery powered headlights on my mid-fork braze ons, and I didn't want to spend a lot of money, in case I didn't like it.

I ended up liking it so much, I did it to two bikes. If you've been on the fence about trying it, I suggest you do. Everything you see cost me less than $10. The most expensive part was the can of paint.
Here are my results:



I got a few PVC end caps from the hardware store, and a few different washers. I drilled holes in the middle of the end caps and painted them black, then bolted them on.

Pro Tip, get the biggest washers that will fit inside the end cap. Drop the washer into the PVC. If you do it right, the washer will center itself in the cap, and that will give you a guide hole to drill a perfectly centered bolt hole.



The 1/2" PVC end caps have an OD of ~27mm, while the 3/4" end caps have an OD of ~33mm. Neither are the perfect diameter for this application. The 1/2" is a little shorter, so I decided to go with the 3/4" so the lights would be offset a little wider. Luckily my Cygolite mounts could accommodate the 33mm diameter. My old NiteRider MiNewt 600 clamp wouldn't close on it tightly enough.

I found the secret to keeping the PVC from rotating was to use the washers. They compress a little, making everything more snug. I added the star looking washers between the flat washer and the back of the PVC so that it gripped everything tighter.

I've been using them for quite a few months now, and I haven't had any major problems, even riding rough gravel roads and some singletrack. Every once in a while, when taking the lights off to charge, I'll tighten the bolt just a little, to make sure it's all snug.

I experimented with rear light mounts, but with my frame, I didn't find a mounting spot I liked.



One downside is that the lights cast a weird shadow from the wheel. It could be annoying to some. I found I like the extra free handlebar space and the depth of shadows more than I dislike the weird wheel shadow. With my handlebar mounted lights, the light would hit the ground and wash everything out. If there was a hole or a rut, you couldn't tell because there was no shadow. With the lights mounted lower, I can see the holes better, and avoid them.