Is a MTB tire the fastest and best tire for Gravel racing?

Leadville is just a chunky gravel race isn’t it?


I’ve never done it, but that’s the impression I get. Tires do get punctured and sliced, but you don’t hear talk about it like Unbound or Big Sugar.

1 Like

I like maxxis assegai in DH casings. Never flatted even running low psi.

I have, and my opinion is, no, it’s not. There are plenty of defining sections on that course where you would absolutely hate life on a gravel bike, and I still think a full suspension 120/120 XC bike is the right choice for pretty much everybody on that course unless you’re starting in the pro field, and even then a very valid choice. While not tire killers, descending Powerline, the top of Columbine, and Sugarloaf there’s a lot of chunk and crap where you see people flatting and are real MTB descents IMO.

I’m a fan of the Race Kings with Vittoria Airliner XC Inserts, and will use them again when I’m back in 2024.

1 Like

The Thunder Burt isn’t a very “big” 2.35", but then again the RK is a very narrow tyre too.

I have also picked up some Super Ground tyres (rear TB) for my A-Race in March. Same reason as you. Protection.

The super race has no “protection” layer on the sidewall, and in the rocky races that seems pretty critical.

I’ve been riding the American Classic Kimberlite 700 x 50. Has a similar pattern as the Pathfinder. A little heavy, about 60 grams per tire more than the smaller Pathfinder 47. Never had a puncture and they roll well on pavement as well. Ran them at Locos, Worlds qualifier in Arkansas and several local races and my fitness let me down but the tire didn’t.


I was saying it a bit tongue in cheek, as there are very large parts of the course would be faster on a gravel bike. So you would pick the race king over the larger thunder burt?
I lean towards preference of larger tires for the terrain, and I haven’t run 2.2 tires on a mtb in 6-7 years. I wish the aspens were faster. Their volume is awesome

1 Like

I’ve ran both of these this past Summer, although only the 2.25" Thunder Burt, but want to try the 2.35". They’re very similar, with a slight edge to the Race Kings for cornering traction on loose stuff at speed. While I haven’t had any punctures on either, given everyones fears of the fragility of Race Kings, I’d probably “trust” the Thunder Burts(SuperGround) a bit more for a rockier course but this is just more gut feeling than science. If I were to race Leadville again, I’d almost certainly go Race Kings, on wide wheels(32mm internal hookless)…

There are absolutely sections faster on a gravel bike, there are road sections that’d be faster on a TT Bike. But overall, absolutely going to be fastest on an XC bike. And for most people, I think a FS XC Bike. (Although DJ is arguing for a drop-bar MTB)

I haven’t run Thunder Burts, but the Race King did not leave me feeling like I needed anything more. A lot of people consider them the perfect Leadville tire because there are the road sections, smooth gravel sections, and a whole bunch of climbing, and I think they’re rated as good or better as the Thunder Burt depending on the category by BRR.

Leadville doesn’t strike me as having a lot of sharp / jagged rocks that’d take out a sidewall, but definitely a chance for hard impacts on the descents.

32mm is a huge internal width for 2.2" tyres. How does the shape end up?

I’ve gone back to 27mm from 30mm ID rims and the roundness of the tyres seems to provide more predictable grip.

1 Like

I rode Leadville twice on Race Kings on 25mm wide rims. I now have 30mm rims on my bike. I’m not sure how the profile of the 2.2 Race Kings would look on them. I’d be concerned about the side walls being too exposed. I haven’t put the Race Kings on the 30mm rims to check, but I suspect I’d prefer a 2.35 or 2.4.

I wish they got with the times and made the Race Kings in 2.4


A few years back, I pinch flatted a tire when I was pre-riding the sugarloaf descent. For race day, I put a few extra psi into the Race Kings as a safety factor. Nowadays, I’d put in a Vittoria Airliner insert into the rear, and revert to normal psi.


I am running the Airliner front and rear with the Race Kings, worked great for me this year. I personally can’t notice any feel / performance change at all with the ability to run low pressures, they’re light, and the added safety.

This is on a second set of wheels that are 25mm internal. I have an every-day set that’s wider with bigger tires I use for most riding, and I too would love to have the option of a 2.4 Race King.


Assuming you have the frame clearance, could you run a Thunder Burt 29er tire on a 700c gravel wheel (tubeless, of course)?

(This is where my lack of MTB experience over the last 20 years really shows. :wink:)

It sounds wide, but we’re running 28mm(labeled) tires on 25mm internal width on the road, 45mm tires on 30mm internal on gravel, so proportionally, it’s not at all crazy to run a 56mm tire on a 32mm internal rim, and in fact less crazy than the former ratios. The Race Kings handled the shape really well, as do Vittoria Mezcal and Barzos. The Thunder Burt 2.25 squared off a bit more than the others.

I am running the 2.1" Thunder Burt on my Mosaic GT2x(Ti Gravel Bike) with 30mm internal width Nextie rims. They’re really, really good in this use case! They don’t square off as much as the 2.2" version I mentioned above, nor as much as the 47mm Pathfinder Pros. On a 25mm internal width rim, they’d fit(albeit limited mud clearance) on my Crux, with 2x GRX…


Which year Crux…one of the newer ones?

You’re right of course. But slicks are a little less dependent on shape for using the side knobs.

Gravel and XC wheels are essentially the same thing. Just different hub spacing.

1 Like

Not sure I’d be willing to take my HED Emporia Carbon rims and have them relaced on to MTB hubs so I could take them out on my FS XC bike. Zipp might feel the same way.

My XC wheels are marketed for both XC and Gravel.