A while ago I started to experience a slow leak with my front tubeless tyre. It was slow enough that I could pump and ride but tended to be noticeable the next morning. The general feeling on here was that it may be the tape failing.
Then a couple of weeks ago I found it flat, pumped it up and heard a hiss, there was obviously a fairly rapid loss of air. It was at the top of the tyre as it had been left, so I assumed that the sealant had drained to the base (hence not sealing); I span the wheel and it sealed so I rode without issue. I did put a mark on the sidewall so I could leave the tyre, puncture down just to pool the sealant and make sure it had sealed properly.
A couple of days later I found the tyre holding air but the bike was stood in a pool of sealant (the tyre was completely drained) - refilled, rode, no problem. However, although the tyre appears to be holding air it seems to be continuing to leak sealant if the bike's stored puncture down!
I've cracked the bead and felt around inside with my fingers and can find no foreign object and I can't see a puncture hole to try a slug in. If it's still leaking air it's not detectable so I can't locate a hole that way; there's no bubbling of the sealant where it's leaked onto the tread.
Any idea what's going on? It still seems rideable but it's rather perplexing me. Can sealant go off? It's fresh in the sense that it's recently be replaced but it is the tail end of a very old bottle (have bought some new stuff) - Stans by the way.
Sounds like a rim tape problem to me?
how easy is it to get the tyre on initially ? - I wonder if an extra wrap or two of tape might improve the fit
Surely if it was the bead/tape the sealant would leak out whichever position the OP put the tyre in, not just hole down 🙂
The sealant is definitely leaking through the tread.
Pump up the tyre to as much as you dare, then Fill up the bath and dunk it in
have found a few small tubeless holes this way
Fill up the bath and dunk it in
You forgot to preceed this with 'make sure husband/wife/significant other is out first...' 🙃
Surely if it was the bead/tape the sealant would leak out whichever position the OP put the tyre in, not just hole down
surely just air if the hole was at the top; sealant & air if at the bottom
If "definitiely leaking through the tread", you must know where. Fill that hole/fault
Tried squirting the entire tyre and rim in soapy water? I find even the slowest of leaks will start to bubble
Yep, paintbrush and really concentrated soapy water all over the tyre should find your culprit. Make sure you paint the rims/valves as well even if you don't suspect them.
I had one that drove me mad. Turned out to be a very small nip in the bead which intermittently sealed. But would then (in the dead of night), re-present itself, leaving sealant all over the garage. Pump it up and it would hold air. For a couple of rides, at least.
Is there a loose or partially dislodged tread block somewhere?