gregk wrote:
Sparks wrote:
I'm in the midst of my first foray into the world of tubeless, road or otherwise. The rim/tire combo of HED Vanquish 6 and Conti 5000TL seems to be a good one so far. I can get the tires onto the rims by hand and without too much effort. The beads seat solidly with an air compressor. But I am having issues getting them to hold air.
Long story short, I re-taped them with two wraps of Stan's, and tried airing them up right away. The result was air leaking out the weep holes on the side of the rim and the time deflating from 90 PSI within 5-10 minutes. I decided to try re-taping them with one wrap of DT Swiss, and tried airing them up right away. This tape job seemed really good since I was now a veteran, but the result was the same. So I put tubes and a different set of tires on and rode on them for four days. I put the tubeless tire back on the front today and aired it up to 74.6PSI at 9AM this morning. I checked it at noon and it was at 73.2. At 3PM it was 72.6. And at 5PM, 72.2. Major progress compared to where I started.
Now for the questions: Dump sealant in it and see if it seals up completely? Or re-tape, put tubes in for a day or so, and try again? I wonder if airing them up right after re-taping them caused some small gaps between the tape and rim that I just can't see and that the tube couldn't seal.
ETA: I have more tape and am willing to try re-taping. I'm interested in getting this done right, not getting it done quickly.
"The result was air leaking out the weep holes on the side of the rim"
Weep holes... are you talking about the water drain holes that some deep section rims have? This is usually somewhere in the sidewall of the rim, fairly close to the brake track (but designed to drain water from the large aero rim cavity). If that's what you're talking about, this tells me that your tape is not seating down properly, and air is leaking through the spoke holes and into the other part of the rim.
^If this is what's going on, you want to remove the tires, and tape. Clean the rim bed out VERY well with 90% rubbing alcohol. If it was me, I'd install two wraps of new tape (i.e. Stan's, or whatever is the appropriate width for your rim). I say two wraps because it sounds like the interface between that tire and rim is possibly a bit loose ("I can get the tires onto the rims by hand and without too much effort.")... which can also lead to potential air retention issues. Wrap the tape TIGHT. Once the tape is installed, I'd install a normal tube and tire, and inflate it to 90psi and let it sit overnight. This will help stick the tape down. Remove the tire and tube, and install the Cont tubeless tire you were using (along with the proper tubeless valve... I'm not sure what HED gives you with the Vanquish... but if you have the wrong valve, they can leak).
Also, I see that you haven't used any sealant yet. Road tubeless tires are NOT going to be perfectly airtight without a tubeless-specific sealant. The only tires that will be "airtight" with no sealant are older, now-defunct MTB tires that meet the old UST standards (these tires were super thick and heavy, but super easy to deal with in terms of inflation). And even when you do use a tubeless sealant in a road tubeless tire, they will still leak down over time, just like tires with tubes. If you really want to limit the leak-down, you can try this stuff:
http://stayfill.com/ Water drain holes, yeah, that's what I meant. After running tubes all week, no air is leaking from the drain holes, but I think air may still be coming through the spoke holes. I tried putting a soap solution on the spoke nipples, but the leak down is so slow, I did see any bubbles.
DT Swiss calls for one wrap (I'm pretty sure it's the same as HED's black tape, which HED says to wrap once), but I could certainly try two to tighten things up.
I didn't want to use the sealant to try to mask a fundamental problem. I'll definitely use it once I get these relatively air tight.
I'm going to re-tape them and see what happens. What's reasonable in terms of air leaking/PSI loss? In other words, how can I tell if I've resolved tape, valve, seating issues? They don't lose any pressure in an hour? Longer?
Mike Sparks
I have competed well, I have finished the race, I have kept the faith.