Sorry I missed that.
I’d go with Recon F Ikon R. Since you have those tires, I would even consider testing them as well as combinations. Would throw the Dissector in front just to see what the differences are and have fun analyzing.
I did that last year and while I really like how my front tire performs, I know its a bit slow, so I know looking for similar tire with lower rolling resistance is the right path for me.
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Reducing the impedance is clearly the most important once you’re on anything but very smooth surfaces, per the Silca chart, because once you get above that breakpoint the required power goes way up.
But if we’re comparing similar very supple tires in very similar widths and pressures, then we can rely on the BRR results to at least rank which tire should be fastest in real world roll down tests.
Of course a really big factor is how confident you are on the tire on the terrain you will be riding, as well as flat resistance. If you have to brake more or crash or get a flat, saving a few watts was meaningless.
So final conclusion is make a list of the widest tires you can use that fit your needs (traction, handling, durability, price). If you like several of them, the BRR data can tell you which should be faster. That’s the easiest way.
If you can really be super careful with testing you can do your own tests, but chances are all you’ll find out is which tire you were fastest on, not the root cause, at least if you’re testing on XC trails. Maybe it was faster because it led to less braking, better cornering, or really did just roll better. Maybe it was some factor you didn’t control for (fork oil temperature, not taking the same line, etc). If you do enough runs and swap back and forth a lot you at least can say what gave the better performance. At that point you really don’t need to know why, just use it.
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I’ll be interested to see how the Aspen ST 170 are in terms of durability and flat protection for you, since Maxxis says the Team Spec tires “are for race use only,” which I interpret more as a hedge vs. a marketing tagline.
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Jumping in here… I just put Rekon’s on the front and Rekon Race on the rear. The rear is a 2.4 120 TPI. On my second ride I pinch-flatted (I’m 170lbs and running 25 PSI, no inserts), Replaced the tire and flatted 1st ride on the new tire… I’m really not riding that hard. Do you really have to be super careful picking your lines with the Race? Its pretty rediculous. Are Rekon Race’s junk? Never had this issue with another tire (same trails).
Which Race 60 or 120 TPI? With or without inserts? I’m having horrible luck with the Races, Two tires, two pinch flats…
I remember that video, and I guessed which one it was even before clicking on the link. He put a lot of thought and effort into the test, and as you say, it’s a lot more rigorous than most testing that gets done. I liked that he also highlighted the limitations of the testing, which most people don’t do and that’s generally a good sign, that he’s critiquing his own test.
It was that video, five years ago, that motivated me to learn more about statistical methods like T-tests, confidence intervals and uncertainty quantification in general (also for the benefit of my job). I think we could use those sorts of methods more often in the tyre testing we all do, to quantify the effect of the variability we get in results. Instead many of us, myself included, usually rely only on our gut feeling whether one set of test results are sufficiently different to another set of results, to judge whether it’s a meaningful difference or not.
The variability is a real challenge for testing the rolling resistance of MTB tyres. The nature of MTB trails, with rocks and roots makes it difficult to create a controlled test in real world conditions because of the variability in line choice (e.g. did I hit that rock on the last lap?). It’s somewhat easier for testing gravel, and perhaps cyclocross, but MTB trails are tricky. In my own testing, I’ve used a grass field to get less variability, to make it more controlled, but then the test become less representative of bumpy MTB trails. I think there are ways it could be done, but you’d have to build dedicated tyre test trails. The way we try to overcome this, and testers like @Joe do this in the results he has posted in this thread, is lots of A-B-A-B repeats to mitigate the variability. That takes a lot of time and effort to collect the data though. Or alternatively we look to controlled testing like BRR which identifies some of the rolling resistance losses relevant to XC riding, but not all of them.
Somebody recently told me about this Trek tyre testing treadmill machine (video here), which looks very good, and as a test method it looks like it could address some of the weaknesses of BBR type drum testing for bumpy off-road conditions.
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Apologies if I missed it but I had the opportunity to view the new new Peyote at a sponsor stand last week. I wouldn’t rider that in anything but dry, its almost a gravel tyre - slick while upright and very small tread outside of the centre.
I also learned the new “XC” grade at Vittoria is a budget version heavier that the Race or TNT’s, relying on a thicker sidewall without the TNT and a single compound rathe than the 4C of the others.
Actually, he didn’t say that. At 18:14 in the video he says, when talking about the 0.07% and 0.14% differences: “…on the rougher and steeper climb I found no significant difference between all of the tyres.”
It was instead the smoother climb (at 18:53 in the video), for which the % difference was larger (1.2-1.5%), that he said there was a significant difference relative to to the 2.3" tyre. We don’t have access to his raw data, so we can’t see if he made any mistakes in the processing of the data. To pass the T-test with a 5% probability criteria, and assuming he did a few runs with each tyre, he would need to have need a difference in average times (i.e. the 1.3-1.6s difference) that is about 3 times larger than the combined standard error of the two sets of data.
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Because you’re clearly biased and just hate maxxis for some reason only known by you. If it was a “Doggshit tire” it wouldn’t be the most winning tire in xc racing, regardless of sponsorships. This is mountain biking, there’s more to it than rolling resistance. There’s also flat protection and grip. If all you care about is rolling resistance you may want to stick to gravel or road riding.
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#BroXience
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That’s good to know about the Vittoria XC grade. Probably also why the TNT version of the mezcal and barzo performed better on the drum test.
I run the north 60tpi and 120tpi, typically with inserts. Just raced Moab Rocks with 60tpi which is smooth rock but endless chunk and hard hits. I run inserts and I’ve had no issues at all with the tires. Ran a 120tpi pair all last summer in Colorado racing (Breck Epic, etc) with no problems with them.
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Thanks. This is exactly the response I’m looking for. How heavy are you and what psi? I also did Moab rocks and flatted on day #2. Replaced the tire and flatted at Lory.
Cheers
I weigh ~155-160 without kit/gear. I ran 16.5/17.5 for stages 2 & 3. 1-2psi higher for stage 1. 25mm wide Enve M525 wheels with Tubolight Evo SL inserts.
And actually, edit to my earlier statement - I ran 60tpi (tan wall) at Moab. That was a new set I put on. I ran 120 tpi (on different wheels, 30mm wide, similar pressures) at Breck last year.
I think I found the forum: Wheels and Tires | Mountain Bike Reviews Forum
But not the tests in there.
You need to read through the race tire thread or search for his posts. It’s not a separate thread.
All valid points and yet it is as good as you can get… w/o downright doing Chung Virtual Elevation Testing which is practically the gold standard for real world rolling resistance and air resistance testing we have but also isn’t applicable for all use cases like e.g. actually testing down hill times taking into consideration aspects like cornering gip etc.
And the video also proves that you can be extremely thorough and considerate and yet leave some angles open or still have done too few (of already many) repeated test runs to show effects of variations etc.
Case in point - the reply I gave to the person relating the video-link to me on Threads contained among other points:
"He mentions the pressures were adjusted relative to casing tension. But when I calculate it I get relative factors of 78.8 for the 2.3“ and around 83.5 and 83.9 for the 2.6 and 2.8“ tires. So these were effectively a tiny bit more firm. He also mentions a bit higher bounciness. All in all good and thoughtful explaining of the issues, though. So still - an excellent video and test. I think short of real Chung Virtual Elevation testing for pure rolling resistance you can’t become better.
So this video confirms what I need to know for my use cases: XC-Touring and Bikepacking over mixed terrain (still so offroad that a Gravelbike would be underbiking). Where it counts for me is where I really pedal and make ground. And the more technical it gets (his decending test shows loads of off-camber roots - and it’s clearly from an enduro or trail riding perspective) and the more gravitation is on your side, the more beneficial the bigger tires become. That you get more grip and cornering traction with a bigger tire (all things equal and no squirming or even collapsing tires given) is a fact."
I went on explaining the weight matter and other stuff.
But the point still stands: as far as Youtube Tire tests go, this is one I can really say we find meaningful information and meaningful datapoints. I would be hard pressed coming up with a much better protocol and reasoning he applied for his question.
Whereas many others are just some people making a nice show (hopefully at least somewhat entertaining) but their “results” are as arbitrary as rolling the dice.
In regard to controlled testing and rolling resistance for the same tire construction: Yes. And: That is the other and the first part I gave as an answer to the respective person in my mentioned Threads conversation. It’s a slight different question and more importantly: it omits the part of grip (which isn’t a rolling resistance question but on the right course definitely a parameter of speed) and it also omits the part of impedance losses (for which you need an actual rider - but… also especially Jan Heines Tests to which you link are also very much prone to critique. For example he does way to little repetitions and doesn’t control well for the way bigger effect then tire rolling resistance which is aerodynamic drag. You would be surprised how variable this is even when the rider thinks he is super consistent).
To make sure nobody reads and understand this post, I’ll also include said first part of my answer I gave upon receiving that video link. Which was:
"That is an excellent video! I explain why (and probably telling you nothing new) in a minute.
But first: why are wider tires faster, just in terms of rolling resistance and hysteresis alone (all things equal: compound, casing, surface). Or aren’t they at all?
For equal pressure and on a hard, smooth surface - no doubt. Wider is faster. But of course no one would want to ride that. The casing tension would sky rocket, the tire would be much harder, way less comfortable and depending on size, pressure and rim technology, even burst from the rim (hookless) or destroying it.
So there are 2 effects at play: equal pressure but bigger tire means harder tire and thus less tire drop. Less tire drop = smaller contact patch. Smaller contact patch = less material deformation and less hysteresis losses. The theory suggests, that even with rising tire drop of the bigger tire, even as the contact patches near the same area, the contact patch of the bigger tire is wider but shorter in the direction of travel. This leads to less „bulge“ and material being deformed even when tire drops are becoming equal. Thus less hysteresis losses. Again, only on smooth, hard surfaces. Now does this hold true or is the total amount of material „squirming“ in direct contact to the ground somewhat equal, still?
At least this test suggests it. Continental Grand Prix 5000 23, 25, 28, 32 mm Comparison
It confirms for 4 sizes of the Conti GP 5000 on drums that for equal absolute tire drop (4.5 mm) and thus equal comfort levels the rolling resistance comes out as a flat line. So indeed - for hysteresis losses alone a wider tire is only faster if it is harder. Put differently: you gain the same level of speed and comfort with any tire of the same make.
Comfort is in this case also just another word for suspension in the tire. Which directly affects the second aspect of total rolling resistance: the impedance losses through vibration energy dissipation caused by rough surfaces.
So, if you can reach the respectively needed tire drop, i.e. suspension to get to the intersection of rising hysteresis losses and decreasing impedance losses by decreasing the pressure in the tire (really by decreasing it’s casion tension) with a smaller tire you’re golden. You have your comfort, you have the fastest speed over the surface and the lightest weight and lowest frontal area.
Now - the heavier the rider and the rougher the terrain, the faster a smaller tire reaches it’s limits. Against bottoming out. If you want/need 10 mm tire drop but you run a 25 mm tire you’re out of luck and this tire would be pretty unstable to reach that high of a tire drop percentage anyways.
So the real core of the „wider tires are faster“ lies in the fact that (for road as well as for offroad) we have hammered that message long enough into the minds of riders and the industry that even bigger, heavier blokes now can ride a tire (say at least 28 mm for road) which gives them the needed tire drop w/o danger of bottoming out, pinch flatting and so on.
Most people nevertheless don’t get it right that or why wider tires are faster. For road they now think: oh, wider = faster and more comfortable. And if they then have a ride which is more comfortable and they like it: that’s mission accomplished. But if they want to be the fastest on a given course then they most probably have to give up a bit on the comfort again and they will find they are faster. But equally fast on a range of appropriate tire widths.
What is overall faster then? That tire width out of all which slots most optimal into your system and the course characteristics. Since we haven’t yet touched on other parameters of speed like cornering grip or cornering confidence and on the wheels we have. Or how hilly and steep the course is. "
Have fun! 
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That’s the gist of it.
Tire selection is so interesting / nerdy because you want to optimize for or strike a balance out of competing properties.
The ideal tire should be comfortable, fast rolling, offer traction, cornering grip, weighs nothing, never flats (bullet proof), has no frontal area (is super thin) etc. pp. Most of those diametrical opposed to each other.
So rolling resistance is but a part of selecting a tire. And the priority of weighing those factors shifts from rider to rider and event to event.
But my main point is and I think you are saying the same with this:
- Pick your most important factors you need / has as priority and from there choose the tires which all are in the same ball park of reported or tested grip, puncture resistance or size you prefer and look for the fastest rolling.
- Or vice versa: look up the best rolling tires as a range and pick the model which has the most of the other properties you are looking for.
What you shouldn’t expect is, that somehow “the real world” would have it that a super slow tire construction (compound and casing) would somehow turn the ranking of low rolling resistance (even if tested just as the hysteresis losses of that tire) completely on it’s head.
That’s what I mean when I say that up to now I only found tests (if they were done with knowledge of all the other variables like aerodynamic drag, variance in surface conditions over testing durations etc.) which confirm the ranking of such tests like from BRR.
Of course: the many “tests” á la GCN et al which consist of “hey, I have a power meter and I rode this course once with tire A and then once with tire B and did my best to stay at the same power” can’t offer anything in this realm.
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But…
My 2.4 Kenda Rush Pro SCT are faster (just a tiny little bit faster, but faster) than my 2.2 Continental RaceKing Black Chili Protection in real world conditions.
According to BRR the Rush are ‘a lot’ slower than the RaceKing…
I’m not saying that BRR results are totally useless but real world conditions add several variables that simply cannot be measured on a drum with tyres pumped up to high pressures.
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Are you running these front or back or both?
Joe