I picked this up off another forum. Any of ya'll tried this.
Tubeless for under $10.00!!! 8:58 AM 6/5/2005
I finally got around to making my rear rim tubeless. I will do the front one next, but I am waiting until the next time I need to change the front tire.
Here's what you need: A tubeless type valve stem, a large cylinder of clear silicone (get at any hardware store), a calk gun to apply the silicone with, and duct tape. That's it.
Clean the inside of the rim off very well, and let it dry. Then apply a big blob of the silicone over each spoke nipple. Let the silicone sit for a few minutes and form a "skin", but not totally dry. Then, take the duct tape (this part is much easier with two people - one to hold and secure the tape, the other to turn the rim) and tightly wrap it around the siliconed spokes. Do about 3 or 4 full wraps with the duct tape, and let it sit and cure overnight. Oh, you'll obviously have to cut a whole in the duct tape at the base of the new valve stem. Also, but some silicone around the base of the valve stem. I suggest filling the tire with air right after applying the duct tape, I think the extra pressure helps push the silicone into all the right places.
It sounds cheap and I was skeptical at first myself, but I figured what do you have to lose? My first test was filling the tire with 60 psi of pressure and letting it sit. No leaks. My next was a quick run around the neighborhood. No leaks. I've done 450 miles on the bike since Friday, and it hasn't lost a tenth of a PSI of pressure."
Thoughts?