[Closed] Conti Mountain King 2.4 Tubeless deflating overnight

In my experience conti tubeless ready tyres take a few weeks to seal all the little holes in the sidewalls. There can also be a problem with the handmade tyres still having the mold release agent still inside the tyre, and it can be worth giving them a scrub before fitting.

Often I get this with tubeless, but once ridden they are usually fine.

I found my front 2.4 to be fine, but my 2.2 rear seemed to leak a bit out of the sidewalls. It then sealed itself, but has started to leak sealant a bit.

What sealant are you using? My Stans stuff was useless - swapped to JRA Wheel Milk and I had less issues. I find that the JRA stuff tends to dry out a bit, blocking the little holes.

It's the mould release agent and more porous sidewalls thing. I suspect that Continental use less rubber but more thread in the casings to keep the weight down as black chili rubber is denser (due to less small air holes) than other compounds. Might be worth giving them a clean on the inside if they don't sort themselves out in a week or so.

Reckon it's ok to ride then? It looks like it holds pressure, just not overnight.

As chiefgrooveguru said - I would take them off, clean the release agent off, so it doesn't feel slippery inside, then re-inflate. Still might take a few days to be spot on, but shouldn't deflate overnight.

I had this once before with Mountain Kings. I would just bang a load more sealant in there and give them a good ride to get it moving. I use café latex rather than stans because it can be injected through the valve without even removing the core. After doing this once I never had the problem again.

Are the valve cores ok and are they tight? I had a tyre deflate on me due to a poor valve core, I popped in a new one and it's been fine since.

Yeah, cores are fine. Looks like clean and replace is the safest option. Good thing they're such a baggy fit so they're not a PITA to get on and off.

Schwalbes have spoilt me. Going to get a pair ordered ASAP.

Hi, if you want my two pences worth Conti are awful tyres for tubeless. i had a TK and have removed it due to it constantly deflating overnight, and whilst out on rides i could see little bubbles of air escaping through the tyre walls. i had put 100ml of sealant in too.

i also had an issue with the bead sealing after denting my rim.it would seal but i coluldnt run the tyre at low pressure as the seal 'spilt' when cornering (at the point of the dent)

Took wheel and tyre into the bike shop and the guy working there said he sees this alot with conti tyres and doesn't recommend them tubeless. I've since gone to a maxxis shorty and no problems whatsoever.

I am lazy so I would definitely take them for a ride before I bothered with any faffing around. I often find the jiggling of a ride seals the tyres up better than my Stan's dance does.

It's the mould release agent and more porous sidewalls thing.

(also got an MK2 UST 2.2 on a stans rim and that holds pressure OK - but they're obviously more geared up for tubeless)

Got same tyre and had same issue. One ride fixed it.

Yeah, cores are fine. Looks like clean and replace is the safest option. Good thing they're such a baggy fit so they're not a PITA to get on and off.
Schwalbes have spoilt me. Going to get a pair ordered ASAP.

No-one else does as good rubber compounds as Continental though!

Conti recommend this palaver before mounting their tyres to compensate for their hopelessly shit sidewalls

Yeah, I saw that painting thing. Wish I'd known prior to splooging them.

Not seen that before. Probably not really necessary. Just a good clean, inflate with 2 cups of stans, give it a big shake, ride.

It's the mould release agent and more porous sidewalls thing. I suspect that Continental use less rubber but more thread in the casings to keep the weight down as black chili rubber is denser (due to less small air holes) than other compounds. Might be worth giving them a clean on the inside if they don't sort themselves out in a week or so.

+1 for this. Also, if you haven't already done it, using some soapy water to check air isn't leaking out around the valve or spoke holes (sometimes the tape doesn't seal properly)

Throw a bit more sealant in, take it for a ride - it'll be fine.
I tend to put 2 of the little stans bottles in a 2.2 29er.

Seals fine though and brilliant tyres.

Yeah, contis do that, go ride them, they'll be fine after that

no issue with mountain king protection or baron apex mounted on mavic UST rims - 60ml stans in each tyre

I had stupidly thin Speedkings in the old days, before tyres were advertised as tubeless ready, and they took a few months' worth of rides before they'd stay up reliably.

However in those days all tyres took at least a whole ride before staying up.

Front tyre seems to be holding pressure fine overnight now. Took it out for a ride and both of them stayed up no problems.

Bit disconcerting being pinged about with 30-35psi in there. Going to let it down a bit and take it out again soon. Let's see how low it'll go before it complains.

You'd be better off ensuring you have a reliable bead before you start dropping pressures too low.
I've run up to half a bottle of revoseal in some cases, you need to be able to hear some additional sealant sloshing around as with the higher volume of these tyres, sealant coats the inner surface pretty quickly and without any extra, theres nothing to fix any voids/gaps etc.
IMO, always insert sealant through the valve hole (core removed), there's no reason to break your rim bead open unless you've worn a tyre out or you have to tube repair a flat to continue a ride.

I thought running it with the higher pressure and riding it meant the bead would have engaged? I can put some more sealant in no problem. I've got one of those bottles for it.

Yeah, this is perfectly normal behaviour for Contis. I didn't do any of the preparation steps above, and my tyres (2.4 Mountain Kings) took an absolute age to seal completely. Like 4 months, 2-3 doses of sealant and 10+ rides.

I advise just get over it and inflate the tyres as/when they need it. And probably buy some different tyres next time.

I need to ride the bike in 6 weeks in Spain. Really don't want a burping tyre on the way down a sketchy descent! Probably order some Schwalbes for now.

It won't make any difference as to whether they burp or not. At least not unless they're losing significant pressure through the course of one ride.

I've just converted using Stans kit and Conti X King and having same problems.

Have held both tyres and rim under water and front has absolutely no leaks, rear has a hole that bubbles once every few seconds but won't heal with the sealant for some reason - both tyres go down significantly overnight.
If that much air is coming out I would have though I would see where from when holding under water?

Sounds like I need to give it a few more weeks.

@Superficial

So what are the actual problems if it won't burp? I thought that meant the tyre had engaged? Do you mean it will slowly lose pressure over time and I'll have to pump it up every now and then? I can live with that, but not with a burping tyre!

The problems you're describing aren't really connected to burping at all to be fair (apart from that low pressure makes it more likely). TBH my experience is most tyres won't stay inflated til they've had at least a short ride so I wouldn't worry about that unless you've got a reason to.

I run Conti tyres tubeless on both of my bikes, had problems getting them sealed with Stans. It just got too runny before it had finished the job. Switched to Conti's RevoSealant for the next tyres and they sealed up after a bit of shaking. Never lost more than a few PSI in a week whereas with Stan's they were near-flat after two days.

I put two scoops of sealant in there. That usually does the job for large volume Schwalbes for over 6 months! The Contis must be quite porous seeing how quickly they lose air. I've not used them before, but the tyre feels ok so far.

Next question is how low to go for a 64kg rider (probably 68kg clothed and loaded?). With the Schwalbes I can go to 9 and 11 psi on a 2.35" 26" tyre on Flow EXs. Will the Contis go that low without problems? The bead seems quite a loose fit.

PS, if you've got a porous tyre, throw in some glitter. Sounds absurd, works brilliantly, makes your tyres [i]fabulous.[/i] I'm on the pink glitter just now, it's a look.

Pink is a little too ghetto fabolous for me.

Teal on the other hand...

Next question is how low to go for a 64kg rider (probably 68kg clothed and loaded?). With the Schwalbes I can go to 9 and 11 psi on a 2.35" 26" tyre on Flow EXs. Will the Contis go that low without problems? The bead seems quite a loose fit.

Is your gauge faulty? I've found I run 22psi in my front Trail King Protection 2.2 (same size as MK2 2.4) whilst I had 18psi in a Supergravity Magic Mary, and I'm about 80kg. 9psi is fat bike or child low!

Reading is from one of those digital Topeak gauges.

There must be a point where it stops being accurate, but it matches the pump gauge in the 20s and a little bit below so no reason to stop believing it at the lower pressures?

Plus my local trails are pretty smooth.

Seems like it has worked. Tyres are now staying up!