Tubeless sealant in the heat?

Hi all

3 or so weeks ago had the bike converted to tubeless with Stan’s and Maxxis High Rollers. The wheels are WTB and also tubeless compatible.

Just checked the bike over after last weekends ride and the tyres had lost about 4-5psi, but i’m putting this down to it being kept in the garage and it being warm weather.

Does sealant evaporate a little bit in warmer temps? The tyres held pressure perfectly when it was cooler.

This is my first ever tubeless setup, and its been good thus far :)

Sealant loses its effectiveness in a variety of ways depending on brand/composition over time.  Stans is particularly famous for turning into ‘stanimals’ (stringy solid mess of latex) inside the tyre – although certainly the first application is mostly going to coat the inside of the tyre anyway.

Generally in the UK Stans’ will probably need replacing every 6 months or so although I’ve have tyres with it happily last well over a year without being disturbed.  In Southern California, apparently 6 weeks or so is typical.  Given the temperatures recently I’d go with that.  Pressures will naturally change with temperature anyway.  If the bike has only been ridden once since setup it may not even be fully sealed yet.  These things can take a little time to bed in.  If in doubt, take a wheel off and shake it by your ear.  If there’s sloshing, you’re good. If there’s no sloshing you can hear, then while you may be sealed you’re not going to survive a puncture so you may want to pop the valve core and add some goop.

‘Orange Seal’ sealant’s claims to fame were that it could survive slightly bigger punctures than Stans and that it lasted longer – IIRC it’s rated for about 3 months in So Cal.

Cheers V, great info in that reply. It’s pretty much confirmed what I thought.

My sidewalls have started weeping in the hot weather, maybe that could also be an issue for pressure loss.

Sealant seals holes, once your tyres are sealed they generally stayed sealed. Didn’t have any problems in much higher temps. I managed 2 weeks in 35-40c temps without touching them once in utah and that included the bike living in the back of the hire car for some of that.

However just like bikes with tubes air goes out over time, it’s normal to need to recheck pressures and top up every so often.

Yes Stan’s does fail in high heat. At the end of day 3 of the Tour of the Highlands a puncture that was previously sealed started pissing Stan’s out and just refused to seal despite reapplication of more fluid. Interestingly another guy who stopped at the same food stop had exactly the same issue. I’ve since moved to Orange sealant as heard it survives heat better due to not being latex based.

I check my tyres before most rides and have noticed the last few times that a few PSI has crept out of the front and back, I have however put this down to the fact I am riding a lot more, and because of this am going faster over rougher terrain and then putting little holes in the tyre which are loosing the air before the sealant seals it.

I rode Dartmoor tuesday night and at the bottom of two descents I had the lovely sound of air creeping out, but riding off to the next descent it sealed up.

I’ve used Stan’s for the last eight years during Greek summers (so 30+ degrees pretty much every day) and I’ve never had to top it up more frequently than at the beginning of May and again at the beginning of September.

Yes Stan’s does fail in high heat. At the end of day 3 of the Tour of the Highlands a puncture that was previously sealed started pissing

I must tell all my Aussie friends to stop using it. Just in case temps get above the highlands….

I had never had this happened to me before in Croatia, Slovenia etc but what I think happened was the tarmac heated up to the point the air inside the tyre heated to above Stan’s operating temp. The tyre had sealed fine about 40 miles previously as it normally would. You must admit it was odd the 2 punctures failing at exactly the same time? It was temps the Highlands hadn’t seen for quite a while.

. You must admit it was odd the 2 punctures failing at exactly the same time? It was temps the Highlands hadn’t seen for quite a while.

Yep it could have warmed up enough that the plugs came out. Having ridden lots in temps hotter than this with stans for 5 years it’s also not something I’ve seen there so maybe it was just 2 unlucky occurances

As. Said check out how the hot places cope fine