The idea is simple, but should offer noticeable advantages. To further increase the protection against punctures in a tubeless setup with sealing milk, a few resourceful Finns inserted a ten millimetre thick foam strip into the tyre and christened the whole thing Huck Norris - the protector of tyres and rims. If the tyre is heavily compressed on an obstacle, the foam serves as an additional crumple zone between the rim flange and the tyre. This should not only protect the tyre and prevent a defect in the carcass with subsequent loss of air, but also reduce the risk of dents in aluminium rims. So much for the theory.
Depending on the rim width, the Huck Norris is available in three different widths to cover rim widths from 21 to 45 millimetres. In the tested width "S" for rims from 21 to 28 millimetres wide, the foam strip, which can be cut to size for any wheel diameter, weighs 73.6 grams (27.5 inches) per tyre. The closed-pore material means that only a small amount of sealant is absorbed. Topping up is supposedly not necessary. However, when weighed after the practical test, the strip weighed 30 grams more due to the adhering milk. If you compensate for the loss of bound sealing milk, the impeller with Huck Norris is 100 grams heavier.
Fitting is simple and uncomplicated. The strip also pushes the tyre apart, which makes subsequent inflation without a tube easier. In practice, the foam strip behaves remarkably inconspicuously. No rumbling, no additional noise and no tougher rolling, as you might expect. With reduced air pressure, muted rim hits are noticeable, but remain without air loss.
And what does the lab say?
The Nobby Nic tested without Huck Norris rolls only 0.3 watts better. The lifebuoy therefore has no influence on the rolling behaviour. In the puncture test, however, the fin settles measurably and reaches a height of 14.2 centimetres more before losing air. Looking at it the other way round, you can ride with Huck Norris 0.3 bar less with the same puncture resistance. However, the punctures leave their mark and punch holes in the €79 foam strips, which is why they have to be replaced over time. Incidentally, our cheap alternative from the DIY store for just under five euros achieved similarly good results.
Test summary by Peter Nilges, BIKE test manager
Huck Norris works and improves penetration protection. Or to put it another way: With the same puncture protection, you can ride at around 0.3 bar less. However, as the foam gets holes when punctures occur and therefore wears out, the price of 79 euros is steep - also in view of the low material value.
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