They are Recip Maxi 3Ds in 235/85r16, although they are closer to 33" in diameter. So far i've been really impressed with them, think they're easily the equal of other aggressive treads available in that size (i.e grizzlies, simex type treads etc). Unfortunately they only do that size so when i go bigger i'l have to find something else as i like to be different.
You don't see them too often though. Quite a few suzuki's seem to have the recip trials but there not as gnarly!
Nick
