Maxxis designed the Beaver to be a mud/wet weather conditions tire. Usually that means a tire that will be relatively narrow (narrow tires cut through mud a bit better) and have widely spaced lugs (mud packs into closely spaced knobs rendering your tire to be a 2 – 3 kg monster if you’re not too careful). The last dedicated mud tire I had was a Panaracer Spike; the name tells you everything you need to know about the tread pattern! The Beaver’s tread pattern is quite a bit less radical; instead of spikes, you get widely spaced, deep wedge-shaped knobs.
The knobs themselves have sipes cut into them. Usually sipes are cut into tread to allow knobs to flex. Flex can change the cornering, climbing or braking characteristics of a tire. That would make sense in an environment where tires are cornered hard at speed on firm ground. I wonder whether the sipes have much use in a wet-weather mud context where the riding environment is inherently mutable. I won’t have a chance for at least the next six months to ride in dry environments so perhaps some other reviewer can tell if these sipes work for their intended purpose.
The Beaver is uni-directional. In the picture below the tire is oriented in its intended direction as if it is rolling down the page. You can see that the Beaver’s intermediate and side knobs have square profiles. The centre knobs have a ramped surface on their forward edge, which is a pretty common tread pattern design to improve rolling ability at the expense of some raw braking power. On the topic of braking power, the Beaver’s side, intermediate and centre knobs have very square braking edges. Finally, note that the side knobs are subtle. They don’t bulge outward from the tire (thus adding to the Beaver’s thin profile) but are tall and seem stiff to the touch.