So I am doing a race in July called the Crusher in the Tushar. It's 70 miles long with 11,000 ft of elevation gain. It's on a mix of dirt, gravel, and asphalt. I am mulling over tire choices for my cyclocross rig. I am going to do the race tubeless. I currently have Schwalbe Sammy Slicks as my tire, but I don't get enough traction when I encounter gravel and bigger rocks. I am currently looking at Stan's Raven, Clement LAS, and Clement X'Plor USH as options for tires. Any input on which one I should go with? My main worry is the 4,000 foot climb I have to descend and then climb - the road is pretty gnarly - gravel, washboard, and 16% grades. Thanks for your help!

Add the Kendra Happy Medium to your list. It has a fast rolling center section and larger blocks on the shoulder and comes in a wide range of sizes.

Thanks for the suggestion - that looks like a good option - I will add it to the list!

Bruce Gordon Rock n Roads roll fast but handle gravel and dirt like a monster.

Looks like a great tire - I don't think I can fit anything wider than 38mm on my bike though.

Yeah, it is a pretty stout tire. I put them on my Salsa Casseroll, which supposedly only has clearance for 38s as well but the 43 BG tire measures true at 43mm and fits just fine. So you'll want to measure for sure, they run at 43 pretty solidly. FYI. Good tire though. Gonna be hard to put the Paselas back on in the summertime! I really like the RNR tires.

Any thoughts on putting a wider tire on the front? Looks like 35 mm is the biggest I can go for the rear tire. Would a wider tire up front help with the bumps or should I just keep the tires the same width? I have a lot of room on the front for a wider tire.

Putting a wider tire on the front works very well. You might also put a knobby on the front and a simi-slick on the back for an event with both pavement and technical trails. The knobby on the front keeps the front end of the bike from washing out on loose surfaces and a simi-slick on the back will roll faster on the pavement. Most of the rolling resistance is at the back tire, and a slick or a simi-slick will help provide a faster and easier ride than a knobby tire.