Running a tubeless setup is the way to ride these days, but when something goes wrong, it can turn into a 30 minute nightmare on the trailside with your mates ribbing you and offers of “here, just put this tube in before it gets dark” and you snapping back “hang on… I’ll just try pumping it up one more time, keep your wig on”. There are two main issues at play here. The first is that as your tyre spins around, the centrifugal force sends the sealant to the outside (tread area) of your tyre so any cuts in your sidewall miss out on the sealant trying to escape and block said hole. The other thorn in its side (get it?) is that no sealant advertises its ability to repair any holes over 6mm, and in the real world I've struggled to seal a 3mm cut.
Caffé Latex has rushed to the rescue and addressed these two issues with some serious innovation. Firstly their sealant is designed to foam when it gets shaken up so is much more likely to get to any holes nearer the bead of your tyre. Secondly, they've come up with a product they call Zot, which is a separate bottle of liquid in 10 or 30ml bottles that you carry with you, and if your tyre cut doesn’t instantly seal, you just push the nozzle of the Zot into the hole and squirt a bit in. What it does is react with the Caffé Latex causing it to bind together in a much larger plug and effectively block any hole up to 10mm.
So I've been riding with this stuff in my rear tyre, but alas I was obviously riding like a nana as I couldn’t get a puncture if I tried. I put this down to not wanting to smash up my very expensive carbon rims, so today I donned my white lab coat and set up a very high tech and sterile laboratory experiment in the Spoke Workshop (the local Z forecourt by the air compressor).
I set up an old tyre that I'd punctured with a snakebite hit on a rock. It had a large (8mm) slash at the base of a knob and a 2mm hole right next to the bead. When I had this 'accident' I actually cracked my rim and it took about ten minutes to get them to seal with Stan's sealant and I had to use a rubber plug on the 8mm hole as well. Also the bead hole wouldn’t seal until I tipped the bike horizontal to make sure the sealant could get to it. Back to the lab. Once I had the Caffé in and aired up I quickly did a lap round the fuel pumps. The 8mm hole tried unsuccessfully to block so I quickly dismounted and jammed the Zot nozzle in, gave it a quick squeeze, spun the wheel and BINGO! An instant seal. Then I remembered the bead hole and had a look and yes, the foaming action must have done its job and got the Caffé all around the tyre sidewall and sealed that baby up. Job done. So YES, it works. Another plus is that the sealant has much smaller particles than its competition, so valve cloggage is very unlikely and when it’s time to take that tyre off and clean up the dried latex, it’s a lot easier to do. My one niggle is that the 30ml Zot bottle has a fat plastic nozzle and is a bit of a struggle to get it into the cut, whereas the 10ml bottle has a 1mm hollow steel needle like a football needle, so I think that's a much better option. In fact I think I’ll jam my football needle in my 30ml bottle now, as I'm pretty sure my footy days are over.
There's a pro trick of adding talcum powder to sealant to get it to clog quicker, and Caffé Latex have already added a similar product. Be aware though that it also has ethylene glycol added which is used in antifreeze and is mildly toxic so don’t leave it lying around in your coffee mug unless your mother-in-law has left you a decent inheritance and she likes a whopping 500ml latte in the mornings.