I'm running maxxis ardent 29x2.25 tires at the moment and I'd say they aren't great tires for wiss. They do ok when it's really dry, but they don't corner very well and they do poorly on the rocks if it's less than bone dry out there. Interested to hear what others are running as I wait for these things to wear out
Light moisture on otherwise dirty rocks and roots will probably be the bane of pretty much any tire with less than very aggressive knobs. The only way to get reliable traction in those conditions will be a tire that sacrifices significantly the rest of the time.
Also, many of the Maxxis tires have what I call a "transitional knob void" in the tread pattern ... at moderate lean they have much less grip than straight-up or hard-over. You may find that forcibly leaning the bicycle over harder will engage more knobs and edges and get better grip. For anything slightly off-camber this applies.
But,
One of the Maxxis tires that does NOT suffer that is the Ikon, both the 2.25 and the 2.35 I have found to be excellent. For the balance of tire weight, rolling resistance/speed, grip, etc, for general riding I find it a tough tire to beat and is my hands-down favorite right now (specifically, the 3c/EXO/EXc model). By choice I'd run the 2.35 on both ends of the bike.
The Ikon is *not* my go to" tire for wet/muddy times, but damp rocks/roots don't seem to be any more a weakness for it than any other tire.
If you want something that is "trail velcro" then I'd think you should look at the Kenda Nevegal DTC, specifically with the Stick-E shoulders. I've always found that a reliable tire, at the cost of rolling resistance. As a plus it also works well tubeless and has a decent treadwear endurance.
If you want "shut up and ride" tires at a great price get online and search for the On-One Chunky Monkey and Smorgasboard tires. The former is 2.4" and the latter 2.25" - they are about 30$ each, full MSRP. Word on the street is that Maxxis makes these for On-One, on the Ardent casing. The tread pattern is much more aggressive than the Ardent though and they don't roll like pigs. They handle wet conditions very well. They both have come in a harder (enduro) rubber - which I tend to use on the back tire - and a softer (TrailExtreme) which has more grip at the cost of mileage endurance. These are the only tires I have chosen to mount three times on my FS 29er in the past 3 years (Ikon is catching up though). I have not bought them in over a year though so I can't promise anything about availability.
disclaimer: I have two 29er bikes, FS bike has OnOne ChunkyMonkey 2.4 on the front and Ikon 2.35 on the back; hard-tail has the Ikon 2.35 on the front and the Ardent Race 2.25 UST on the back.
