I’ve been doing a little tire testing and found my maxxis ikon r + ardent race f with exo casing runs about 30 seconds slower with the same power on a 14 minute XC loop vs. my specialized fast track r + schwalbe nobby nic f. Now…30 seconds, it’s got me wondering…could other tires be faster? (probably!)
I’ve looked at the bicycle rolling resistance site https://www.bicyclerollingresistance.com but it seems there aren’t a lot of current fast rolling tires tested yet. Does anybody have more resources for RR in MTB tires?
Not sure the testing exists or how valuable measuring RR on a drum is for MTB tires? That said the fastest actual MTB tire I’ve tried (perception only) was the Kenda Sabre, it’s got as much grip as it looks like (little) but in a straight line, on hard-packed trails, and gravel they fly. I’d pick them for a non-technical XC, XCO or gravel course, anything hairier and you’ll want more. I’ve only run one on the rear and gave it up after the falls leaves came down here on the east coast.
Purely rolling resistance it’d be an easier calculation, but not simple.
Perhaps you’re 30seconds slower because the NN on the front gives you so much more confidence. Though it’s a noticeably slower rolling tyre than the XC options.
I don’t think you can go far passed the Racing Ray and Racing Ralph, or Racing Ray and Thunder Burt if you’re really going for it.
Mezcals (2.35") and Aspens (2.4") are both fast tires as well. If you google around you can see some other folks who have tested various XC tire combinations. Bottom-line, most XC tires from manufacturers will offer low rolling resistance but speed ultimately comes down to the course and your skill level with the tires on the bike. As an example, I think the front Aspen feels a bit drifty as I lean it over and I don’t love that feeling, which causes me to slow down through the corners.
I agree. I am not a Maxxis tyre fan, but I think the Aspen in 2.4 would be the fastest, genuinely 2.4" option. I’d be hesitant to run them however as I don’t have the skill to deal with the lack of front grip.
I’m about to trial a Thunder Burt rear as my A Race has been shifted from early-Spring to mid-Summer, I’m nervous and excited about it.
I hear you guys about the cornering. On this loop it’s pretty flowy, I only have to touch the brakes on a single corner but it’s sketchier on the gravel tires, no doubt. I’m riding at an “all day pace” so I can get plenty of laps in. It’s about 14-14 1/2 minutes long and I’ve done 50 runs on the lap as of yesterday so it’s getting more consistent.
Just to give you an idea of what we’re doing…yesterday I did 4 laps, 2 with the ikon/ardent race and 2 with the fleecer ride on the same wheellset. Data is below, power is pretty consistent and times are pretty close too.
I second the aspen in 2.4 and find it corners very well for such a fast tire. Much better than the 2.25 version. You just have to commit to leaning it over to those side lugs, which I’m not very good at, but have washed out and the tire managed to find traction once the bike hit that lean angle.
The conti race kings are fast, but they don’t have a lot of grip. Might be able to use one as a rear tire, depending on the course. For a typical XC course with turns and braking, I’d definitely use a tire with more grip for front.
I hear what you guys are saying about grip but I think (though not for sure) that on your average xc trail rolling resistance trumps grip. Now slippery wet conditions….that might be a completely different story. I found I could corner pretty well on these despite not even a mountain bike tire.
If rolling resistance is most important, why are you sold on the 2.5" size? The Continental Race Kings have lower rolling resistance than any treaded tire on smooth surfaces tha I am aware of, and that includes gravel specific tires. Aired down, they climb up anything. Descents might be scary though.
I went over the bars at the top of powerline in training on the same setup, and wanted to blame the tires, but the wheel stopped, because of my lack of skill, any tire would have stopped in the hole I drove into. Thankfully I rode away with only a broken inner bar end and scratched elbow. I have lost the front tire in loose over hard while aggressively turning, it doesn’t forgive when leaned over. The Race Kings climb anything though, as long as you have the power to keep turning the pedals.
Excellent question! It’s because I believe (but am not sure) that wider tires are faster. This is a pretty good article on it…
If I can find a supple casing and small knob wider tire options I think it would be faster. But it’ll have to actually test faster for me to “know” vs. “believe”. I have a 2.6" Mezcal on order now.
I don’t think measuring rolling resistance the way you do for road tires makes any sense with mountain bike tires. It is clear that a Nobby Nick has more rolling resistance than a Racing Ralph, but depending on terrain and purpose, a Nobby Nick could still lead to faster race times. Plus, you add the possibility of running a mullet setup to the mix and tire choice becomes difficult.
And rolling resistance does not include other important characteristics like performance under braking. E. g. I found that all Maxxis tires I have tested perform much worse under braking than equivalent Schwalbe tires. I also like roundish tires more than squarish tires like Maxxis TreadLite (which are no longer made).
Yet another aspect is how wide the range of application is. Maxxis TreadLite are great tires, but have an extremely narrow range of application. If you are outside of that, your performance deteriorates significantly. So if you know that your race is dry, dusty and not super technical (or you have the technical chops to compensate for less grip), these are great tires. But if it rains the day before, you should better change tires.
Personally, my attitude is to stick with two, three tires you like. My poison is a combination of Racing Ralphs (front), Racing Rays (rear) and Nobby Nicks. I always wanted to try Thunderburts for the rear, too. I like riding a mullet setup, e. g. a faster Racing Ray in the rear and a grippier Nobby Nick in the front. Although a Racing Ralph isn’t bad by any means.
I would say that by all means experiment yourself, but having tried the 2.6 Mezcal’s I felt they weren’t as fast as the 2.35 due to the added weight and no noticeable increase in rolling speed. I’d almost guess they’d be slower rolling as the felt more sure footed.
2.35 - 2.4 is really where I find the sweet spot of the XC tyres when balancing speed and float.
You should check in on the XC tyre thread as that is essentially this discussion.
I’ve very much wanted to try the Continental tyres, but I haven’t found the right size and tread combo yet.
I will add that I’ve just installed my Thunder Burt on my rear race wheel and it is well undersized. Eyeballing it, it’s more like a 2.25. I am going to ride it a few times before I decide, but I’m nervous about giving up both volume and grip over the Ralph.
I assume you are aware and just have the names backwards, but the Ray is the front specific pattern, and the Ralph the rear (though some racers do run Ralph front and rear on very non-technical terrain). The Ray/Ralph combo is almost always my go to. I’m going to order a Wicked Will to add to my quiver, then I’ll have almost every corner covered with Will Front, or Ray Front, and Ralph rear, or Burt rear.
Please let us know how you like the Ray/Thunderburt combo. I’m currently running Ardent Race/Ikon and have a feeling I could get a bit more speed with the Schwalbe setup.
Which casings are you running, Super Ground or Super Race and why?
