Fenwick’s Airtight Sealant

We were so carried away with the whole going tubeless thing that we seemed to be ignoring one critical issue – it’s a huge hassle. The whole reason you ride clinchers is that clinchers are much less hassle all round than riding tubulars. OK so there is perhaps still a slight performance difference but it’s largely insignificant for 90% of us; that difference may be more pronounced in cross than on the road, where ever since Michelin threw all their eggs in the clincher basket, clincher tyre technology has been close to that of tubulars. In cross, tubulars still dominate mainly because of their ability to be run at lower pressures, but if you can close that gap then…
 

Securing the tube in place with a nut is essential

It was in researching tubeless that we came across an idea online via a well known, American tech-writer who was having success with sealant filled inner tubes in clincher cross tyres, but using thinner than recommended road tubes. All of a sudden it occurred to us that, though tubeless is its intended application, Airtight is a sealant first and foremost and we hadn’t even tried it as such.

We tried the funnel approach but were not impressed – too messy.

So we changed tack completely and filled some tubes with sealant. We took normal road tubes, albeit lightweight ones (butyl not latex ones) and, aware of a possible weight penalty, filled them with around 20 to 35mls of sealant, which is a long way below the recommended 50 to 75mls for a 23mm to 32mm UST tyre.

The Fenwick’s bottle comes with a nozzle for pouring out the sealant but it’s not ‘accurate’. So we tried to use a funnel to channel the Airtight but it was a bit tricky as the liquid is very thick… We then hit on the idea of using syringes, which can be purchased for just 80p from a chemist. This worked a treat.

We used syringes to put the Airtight into our tubes