Fenwick’s Airtight Sealant

As far a weight penalty goes, for every millilitre of sealant you add, there seems too be a gram of weight added. So in the photos below, we can say confidently that we added roughly 38mls of Airtight. So there is a slight weight penalty, but we think it’s well worth it, especially for cyclocross or other off-road applications for being able to ride at lower psi without risking either normal or pinch punctures.

Lightweight racing inner tube weight pre-sealant is 70g

Inner tube weight post sealant is up to 108g.

The Airtight takes care of the penetrative punctures from detritus on the trails, whilst the thinner than normal tubes which are designed for 23mm racing tyres and we have mounted in 32mm cross tyres, seem to work in helping alleviate the chances of pinch punctures. We have been running them like this for a few months now, so it’s still early stages but the signs are good and time will tell.
 

Full carbon clincher front wheel and tyre prior to sealant is 1090g.

Front wheel and tyre after sealant is added weighs in at 1112g.