I've been saying recently that I see no point in paying a premium for tubeless valve stems, but I just learned the other day that there is a meaningful difference in construction. I cut the rubber pretty close to the stem from an old tube and then continued to tighten the stem nut until eventually I pulled it through the rim bed ... That was annoying to get out! But in general, if you don't cut it too close and you don't go crazy trying to over-tighten it, using stems from inner tubes works great. The downside is that if you leave enough tube around the stem to ensure you don't pull through, it can be tricky to seat tires on narrower rims. E.g. my 18mm-internal-width rims would prefer less interference around the bead shelf, so I bought pack of 32mm valve stems to use on those rims.
I had a hard time getting cores not to unscrew and so eventually just read the internet where people said to use Loctite. Maybe I just wasn't tightening them enough? Anyway, this method works fine for me, but I can appreciate that it is probably messier than if you're able to get the tires fully seated without sealant in them initially.
Yeah, I've only done the valve core method a couple of times, but the valve got gummed up and it didn't seem to make anything easier so I stopped. But it might have been cleaner to do it that way. Certainly seating tubeless tires is a messy operation with various soaps or waxes in addition to the sealant; I do it outside. I've gotten better about not spilling sealant (that stuff's expensive!), but on hard-to-seat tires, I definitely lose some to the process.
Or maybe? http://road.cc/content/tech-news/230...-just-launched
Honestly, I have a Specialized Air Tool Blast (https://www.specialized.com/us/en/ac...-117288/117288) but my Lezyne Dirt Drive pump can seat pretty much anything that the Blast can.
2 layers of stans yellow tape (or similar blue tape like that used by Velocity) is enough for road pressures. 1 layer is enough for MTB/Cross.
Some people "build up" the center channel on non-tubeless rims to help with seating. I've never had to do that, but maybe I've been lucky. (I don't use any rim strip in addition to the yellow tape.)
for most of the rims I've dealt with at the shop, 2 wraps is good enough using stan's tape. At home, however, I used 3M blue packing tape you can get on amazon and according to the innernets, it's a teeny-tiny bit thinner than stan's. So at home I wrap 3 wraps. Haven't had any major issues yet between the two bikes in the house running tubeless, aside from burping in races and getting a bunch of crap in the bead because my GF corners at ludicrous speed.
Yeah, I use Tesa 4289 (bought on ebay), since it is the same tape as Stans but a fraction of the cost. I've considered using the blue 3M too, though I had one bad experience with blue tape (I think it was either the Pacenti or Velocity tape) peeling up after a few tire changes, so I've gone back to yellow.
I'm at a happy status quo* I think. The valve no longer seem to be leaking air (or not nearly as much) and I can still pump air into it when I need to (carbon rims and rocks!) and let some out when I need to (turns out those rocks are really wet and covered with wet leaves and I'm NOT going fast!).
* I haven't bothered to see if I can twist it fully open or closed. I'm good with half open and usable.
OK - so I'm offishully done with tubeless for CX. Got taken out at Biketoberfest by a C3/Twenty-Twenty dude within 2 minutes of start, went down, and ripped the f@cking front tire off the rim. Race over.
DONE. WITH. TUBELESS.
That's 4 races so far botched due to either burping down to rim-riding, or in the last/final case, general catastrophic failure. I'm typically running 25-27psi so it's not a question of pressure.
old skool tubs, here I come.
Which rims & tires are you using? I'm not a 'cross racer, but it seems surprising you've had so many problems. Lots of folks do run tubeless, right? (I know November thinks it's "ready": https://novemberbicycles.com/blogs/b...for-prime-time)
But those are pretty low pressures for a 32/33mm tire, so maybe that just pushes the setup a little too far.
I hear of people rolling tubs off their rims too, but probably not with the frequency you've experienced.
Bookmarks