Here come my thoughts on perhaps the most heralded tyre since the Nanoraptor got the 29incher machine rolling.
The Exiwolf, from WTB, is the supposedly the biggest and most rough-and-tumble 29incher tyre available. It is designed to be robust, offer a lot of grip in a lot of different situations and roll relatively well. The trade off for this is weight.
Oddly the WTB site claims something around 630g for the tyre, but this is nowhere near the real weight. We are talking more like 850g plus. This is not only a blatant mis-representation of the weight, it is incredibly noticeable on both hefting the wheel, hefting the bike and whilst riding.
Good points: it grips; it rolls well, it has a confidence inspiring, robust feel to it - all as advertised then. In addition the weight lends the spinning wheel huge gyroscopic stability.
Bad points: it is heavy; it seems to slow steering down and is somewhat imprecise in wet mud.
So overall? The traction really is good, but the trade off is the high weight. This seems to negate any benefit the traction affords a rider, as the average speed s/he can ride at is reduced due to the larger rotational weight. Consider that rotating weight is oft quoted as being the equivalent of 4x the actual static weight. At 200g per wheel over my current favorite tyre (IRC Mythos), this is an enormous anchor.
Rider seeks tyre: heavy rider, with suspension on her 29incher, who doesn't mind going slow and likes rocks, drops and roots.