Right, I’m in the middle of my first tubeless conversion

Mavic 319 with Nobby Nic (Tubeless ready).

Rim taped, valve in.

Tried to seat tyre with track pump – pointless, nothing doing.

Next step, remove valve core and inflate using one of those little CO2 canisters. First time success (feeling pretty smug at this point!).

However tyre did not remain seated when the canister was removed. No matter I’m thinking I can easily re-inflate (I’ve 5 more CO2 jobbies). So pour in sealant, shake rattle and roll etc.

Try re-infalting with CO2 – no joy, lots of CO2 escaping and presumably some latex (4 canisters left)
Try again – no (3)
Again – no (2)
Again – no (1)
Last canister and it inflates. Hurrah!!

Pop valve core back and pump with track pump to about 40psi

Shake, rattle and roll.

That was about an hour ago.
The tyre is still inflated but it is leaking slowly

Should I re-inflate to 40 psi again? Or just leave overnight?
If the latter, assuming it’s flat in the morning, is it likely to inflate and seat easily (with a pump).

Realise these things are always ‘well it depends’ but appreciate any pearls of wisdom.

Al

Are you using the penguin correctly?

There’s a good chance you’ve ruined the sealant with the CO2. They don’t like the cold, and it can turn it hard and/or blobby.

Could be that you need anothe wrap or two of tape. I’ve also found Nobby Nics a bit of a pain to get seated and inflated even with proper tubeless ready rims, which AFAIK the 319s aren’t.

Indeed the 319s are NOT tubeless ready. This was always intended as a first go, ‘give the simple method a try first’. (And the wheel is from my son’s bike – shame on me)

Good point with the sealant and cold, hadn’t really considered that. I’m also a bit concerned there may be some condensed water in there, from the cold.

Guess just wait for tomorrow and see

Are the rims Schraeder or Presta drilled, as I know that quite a few Mavic rims are Schraeder and have an adaptor, this can be another area for air to escape from.
I had similar issues with Sun EQ29 rims – not tubeless ready, pinned not welded, Schraeder drilled with an adaptor.
They went up, but would randomly deflate when left overnight. I suspect that a lot of sealant made its way into the rim itself!

Have you removed the valve core? Makes a huge difference to getting the air in to seat it.

Buy one of the little brass Prestatyn adaptors and go use a garages compressor. If you take the core out that’ll inflate anything.

Yes, valve core removed

No I’m not using a petrol station compressor.

I’ve tried just tape. Ok on a tubeless ready rim. Never got it working reliably on anything else (although I gave up easily on both wheels I tried it with)

Big fan of the cut bmx tube.

15-30 minutes from start to finish, track pump friendly. Little heavier but ime reliable.

If you know it’s leaking then don’t leave it, as it’s unlikely to magically seal itself. Try to listen for where it’s leaking and shake some sealant in that direction.

If it does deflate overnight and unseats itself, it’s unlikely to seat anymore easily than it has before, but there’s a reasonable chance it will hold just enough air to stay seated.

‘Ghetto’ inflator? 2L pop bottle, couple of old presta valves, and some plastic tubing. Link here – it’s in French, but the pictures will tell you what you need to know.

Mine has worked on everything I’ve tried it on, including 29+ 3″ tyres.