Effective water clearance on a road motorcycle tire of course, as well as generating heat. On adventure, enduro, motocross and other off-road tires, grip on loose surfaces is important, but also durability and mud clearance – it’s no good having a knobbly hoop if it clogs with mud. But in addition to that, tire designers might need to consider how they can make a tire that can put the power down, without tearing up the surface too much.

While knobbly tires are a trend on many custom bikes at the moment, be careful that you don’t compromise the road holding if you’re riding on tarmac – the more extreme tires will not only have reduced hard-surface grip, they’ll also give a much less comfortable ride.