I recently got a new road bike which came set up tubeless (tcr disc). I was experimenting with pressures and one night found out the hard way that I had dropped too low. I hit a pothole and got a puncture in the sidewall near the rim. It didn’t self seal and deflated. I filled it back up with a co2 and tipped the bike on its side with the hole at the bottom it stayed up for a couple of miles but went down again. I topped it back up and rode home. I got home and it was still inflated so i deflated to let the co2 out (heard it permeates faster than air) topped up to 100psi and went back out.
Every ride since (about 5) the tyre has gone down. At first I thought I may have got another puncture but the more I think about it i reckon its the original hole on the side not getting any sealant due to centripetal force. I can hear the sealant sloshing in the tyre so I know there’s plenty in there.

I’m used to mtb tubeless and have had about 2 punctures i have known about in around 5 years and very little other problems. Losing a few psi from a mtb is barely noticeable but the high pressure of the road tyres seems to mean that potentially a lot of air is lost in the short duration it takes to seal a hole. Last night before riding I topped up to 110psi and after 20 miles I had 30psi left and had to limp home.

I’m going to put the wheel in the bath tonight and have a look for bubbles and have a check for thorns/glass etc. If I find a hole i’ll patch it from inside and add new sealant.

So is road tubeless generally as good as mtb tubeless? I’m hoping I have just been unlucky so far.

Another thought is that the bike was delivered to the shop without the sealant which is added by the shop before I collected it. I wonder if its just crap sealant. Looked and smelled like stans though when it was spewing out of the hole during the first puncture.

yeah, patch it. Small holes seal up just fine but the higher pressures make big(ger) holes hard to seal, even if you use anchovies.

I’m on that Stans race jizz, which is a bit lumpier supposedly. We’ll see

Higher pressures and thinner tyre carcass means that sealants can be less effective – I’d put a patch on the inside if needed – you may need tubeless specific patches if hole is more than a couple of mm as high pressures can push a regular patch through a very small hole

My one and only puncture (that i know about) would only seal to about 60psi, I usually ride with 80 but the sealant would blow out.

Clean and patch the inside, I would have done the same but the tyre had seen better days anyway.

Cheers.
I just spoke the shop and the sealant is Stans and was added when i bought it in October.

all the MY2017 Giant that are tubeless ready come fitted with tape and valve, and 2 small bottles of stans notubes solution in the bike box. we leave the tires deflated on the shop floor and setup the sealant as we sell…

Yeah that’s what the shop told me just and said they would have a look if I can’t sort it.

Hopefully I have fixed it. I put the wheel in the bath and there was a massive stream of bubbles from the sidewall where the first puncture was. I’m amazed it lasted 20 miles. It wasn’t a hole all the way through that I could see but a little split on the inside wall. I put a tube patch over it and hopefully that will sort it. I’m very suprised the sealant didn’t do it’s job.

Ive found road tubless to be very reliable and don’t get flats until the tyre is worn out. ( Spesh roubaix tubless tyres )
Not tried any others

If you’ve bottomed out the rim to the point where you’ve damaged the tyre, it might not be salvageable. Road tubeless is great for punctures but not so good for cuts and splits (thinking about it, neither is mtb tubless).

If you have cut it with the rim impact, it’s going to be higher up on the sidewall and more prone to reopening even if you do get it to seal.

Good news. The tyre is still up and at the same pressure I put in last night. Hopefully this solves it and I was just unlucky.
Thanks

Andy

Sidewall cuts = very unlikely to seal