Fenwick’s Airtight Sealant

The syringes made removing the sealant from the bottle easy and were ideally sized for fitting inside a Presta valve core, so we lost very little sealant and importantly made very little mess.

Sucking the Airtight sealant out by syringe

We then tried injecting the sealant into the tube whilst it was already in the tyre. This wasn’t the best method, as it was fiddly and more prone to mess.

Injecting the Airtight into a tube in situ in wheel and tyre was doable but proved tricky

Far better was to hang a tube over a workstand or similar with the valve topside and inject it from there. We quickly got into the swing of creating Airtight filled tubes and the results out ‘on the road’ were quite astounding…
 

Injecting into the inner tube alone is easier

Cyclo-cross riders will know that tyre pressure is a bit of an issue. One of the advantages claimed for tubulars is that they can be run at significantly lower pressures affording the rider a huge advantage in soft, muddy or sandy conditions.

Using our sealant filled tubes we have managed to produce clincher tyres which have been ridden as low as 25-28 psi on long, 3 hour off-road training rides by riders weighing in at 75kgs, without any issues. The same tyres were then raced at 30psi without issue, again by a hefty 75kg rider, taking big hits and mixed terrain in their stride.

In soft conditions you can notice a huge improvement in the amount of available grip and though there are moments when you get a bit of tyre ‘squirming’ under hard cornering it’s never proved to be an issue other than just that, a bit of squirming.