Probs with specialized tubeless fitting

sandy771

just been around at a mates house helping him (unsucessfully) to go tubeless.

He has a stumpy evo comp with tubeless wheels and tyres and a bottle or two of the specialized monkey spunk. One of the tyres inflated OK and stayed up the other was a bit problematic in that once inflated air could be seen to be hissing out of the base of the valve stem and when the tyre was shaken it looked like a small amount water was also coming out.

Mate said that he washed the bike before doing wheels and I am wondering whether water could have got under the rim strip and the water is interacting with the sealant in such a way that it is preventing it sealing. My suggestion was to remove the rim strip completely, clean, dry and try again. However I am not sure whether the rim strip is removable, or even whether this is the issue so wanted to ask on here before he goes ahead.

Thoughts/suggestions?

pilch

Don't think the water is a massive problem, but its probably worth checking everything is dry, clean & seated correctly on the rim strip.

Also check the tyre bead is clean & free of debris/old bits of sealant. I tried the spesh sealant & didn't get on with it, the stuff I tried appeared to be quite thick & gloopy, Stans is runnier... seems to plug all the gaps better, but try this when fitting:-

Brush some water with a drop of fairy liquid on the tyre bead and fit, this does 2 things:

1: aids fitting and helps the tyre to seat on the rim

2: shows up any 'leaks' when you inflate

You will need to agitate the wheel once you have the tyre snapped on to the rim, (check the bead has seated properly) move the wheel about so the sealant gets everywhere, (check for bubbles round the rim) especially if its leaking near the valve, balance the wheel so the sealant collects there - check its tight obviously! Sometimes it takes a couple of goes to get them to stay up.

jairaj

I don't think water should be an issue I use lots of soapy water on my stans wheels.

Check the valve nut is done up tight, you may get a bit of sealant coming through the base but this should plug the hole soon and make air tight shouldn't constantly stream out.

Is the rim strip the blue plastic stuff Spec used in the past? If so, its not reusable its pretty much the same as Stans or superstars tape. It covers the spoke holes to make the rim bed air tight. So if you try to use it again then it might not stick well and you;ll get a poor seal.

allthegearnoidea

make sure that the valve is in nice and snugly, i normally push mine in as much as i can whilst tightening up the lockring on the valve, the rear will use a bit more fluid than the front from the nature of the impacts, landings etc.
water wont make too much difference to it, will most likely just water down the soloution a little, (ive just made my own tubeless goo with liquid latex and de-ionised water mixed) make sure you give it enough pressure to make sure it seats and enough sealant, spin it up a good few times at pressure(50-60psi i normally do), drop to around 40ish and have a quick spin around the blockto spread the sealant enough incase it didnt with the spins, should then be able to drop to normal pressure then and enjoy!

mrmonkfinger

Just sounds like the valve could do with tightening up, and tipping the wheel to get some sealant over the leaky bit.

sandy771

Thanks All, but no - valve was tightened more than enough, removed and reseated. Additional gunk was applied around the base of the valve (inside the wheel) and as the gunk is quite thick (unlike stans) it is easy to get in the right place. The wheel has been spun and shaken.

It is not a wheel/bead issue - we can see where the air is coming out and it is the base of the vavle stem under the (tight) locking nut. As I said there is a spray of water coming out when the tyre is pressurised - this must have been done twenty times when I was there and had been done previously before i popped around to help. But still there is a spray of water.

so its non of the obvious/normal issues....