Huck Norris is a strip of high-density foam, which sits inside your tubeless tyre. It’s claimed to prevent punctures by cushioning the tyre under the kind of impact (think hitting a big rock at speed) that would normally pinch the tyre against the rim.
It may seem ridiculously expensive for what is essentially a strip of foam, but the shape and the materials have been carefully engineered. The plastic foam is far higher density than any “camping mat” it may resemble, and the saw-tooth shape is claimed to minimise any adverse effects on rolling resistance to near zero.
At any rate, it’s currently the cheapest and lightest in-tyre puncture preventer on the market.
It’s available in three different widths to suit your rims and can be easily cut down from 29” to 27.5”. In medium width for 29” it weighs 84g per wheel, but after it's soaked up a little sealant it can weigh as much as 120g, so add a little extra.
Installation is a cinch and after six months riding rocky terrain everywhere from Bike Park Wales to the EWS in Finale Ligure, I’ve had just one puncture. For me, that’s got to be a record! That puncture occurred when running Bontrager SE5 tyres (which I have found to be particularly puncture prone) on a rocky EWS stage with poor quality sealant. Once I added some Orange Seal, the hole plugged back up.
Huck Norris can allow you to get away with lighter tyre casings (I ran Schwalbe Snakeskin in place of Super Gravity or Maxxis EXO in place of DoubleDown), and hit rock gardens that bit harder without fear of puncturing. Otherwise, it has almost no perceptible effect on the ride feel of your tyres.
It may lessen the chances of small scuffs and dents in your rims too, but big impacts can still destroy wheels — I totalled a DT Swiss EX1501 wheel with Huck Norris inside, but, impressively, the tyre stayed inflated.
When it comes to preventing punctures though, it definitely does work (most of the time). The price will put many off, but it could save you money in written-off tyres, as well as the faff of fixing flats.
For those who ride in rocky terrain or enduro racers for whom a flat tyre is nothing short of a disaster, that price tag may start to look pretty justifiable.