Most of the discussion in this thread seems to center around the pointy end of challenging gravel races, so that means riding surfaces that are rough, rocky, and generally tough on tires.
My understanding is that the Extralights are kind of like the Conti GP5000s - very fast and kind of fragile. So they work great on pavement and “champagne gravel”.
But RH tires are notoriously difficult to run tubeless and the sharp, rocky nature of many of these courses leads many people to choose something more durable.
Once you move past the Extra lights to their other casings, RR and other aspects of the RH tires become more average, so you can consider lots of other tires that are better tubeless and have different tread patterns.
I ran the 44 snoqualmie pass tires most of last summer in the standard casing. Here in MN, the gravel I ride is mostly pretty smooth and those tires were really fast on pavement and gravel. Not as good on grass that isn’t totally dry or sand. That all makes sense. No punctures or issues with them at all. These 44’s are also lighter than a Schwalbe g-one RS in a size 40 which I also tried and prefer the Rene Herse.
Got another good one knocked out… Peyote XC Race 2.4 v Thunder Burt 2.1 on rough gravel. Not quite as bad as the rough Emporia gravel but enough to know more than a 40 mm tire might be good.
What is your deduction for what causes the inflection point between the Peyote and ThunderBurt from Cat. 2 and Cat. 3 gravel? I would assume the wider tire is simply better at absorbing the bigger impacts of the chunkier stuff…
This is the kind of data that I’ve been really interested to see for a while. Will be very interested to see how the Aspens fair here as well, especially since volume is really on their side.
This also shines a slightly different light on the notion that Race Kings are that much faster than other wider MTB tires when you consider real terrain and not just the drum test.
Looking forward to additional data and thanks for taking this on!
Can you provide your total weight (bike+you) and tire pressure for each tire at each category of conditions?
I did my first “gravel” ride on my thunder burts last weekend on what was probably 35% pavement, 35% category 1, 25% Category 2, 5% category 3. I was at 24 psi rear and 22 psi front, at a total weight of around 185-190 lbs, and it didn’t feel ideal. This is my first time riding gravel on tires other than 38/42/47mm pathfinders, and it left a bit to be desired, purely from a feel perspective. I wish I could put a better finger on it whether I needed to go up or down. I need to spend more time on gravel and messing with the pressure. I do feel that the front needed to go down a bit as it wasn’t the most confident inspiring in corners.
What did you use to arrive at those PSI numbers? Seems high to me…I haven’t played with any of the online calculators, but based on what I run for my 48’s (~20psi), I expect to be around 17psi for my Thunderburts. (Note - I tend to run lower psi than the online calculators)
According to Silca’s site for 190lbs, 52 mm, category 2 gravel, mid range casing tubeless, cat 1, 2, 3 racing, it specifies 24 psi/23 psi.
During my last race, which was significantly more gravel and also slightly rougher, I ran my 47 pathfinders (that measured 48) at 26/22 and felt pretty good with them. For really chunky gravel I had previously ran them around 24/21 and found that good.
The Thunder Burt rear at 24 felt low on the pavement/tamed sections, but pretty bouncy on the rougher sections.
Maybe I should actually weigh myself with all my gear/liquids etc. My bike is probably around 19, I’m 157 in the buff, and have the typical tools, 3 water bottles, etc. Not sure that there’s a big difference in tire pressure between 185 & 190.
I think you are always gonna run into this situation when using a MTB tire for any extended paved sections. The challenge is whether to optimize for those sections or the gravel…
Yeah, I would let some pressure out as some others have mentioned. The pressure is pretty much the same in all these test it is whatever the wolf tooth App recommends Or the silca one they are pretty similar. That is also why I haven’t listed individual weights and pressures for everything because there is only so much information worth packing in to the post on these. I’ve also been really careful with temperature inside versus outdoors As that can change the actual tire pressure once you are riding.
Can I still use 50 mm plus tyres on a 19 mm internal wheel? Will I be better off sticking with my 45 mm?
I don’t really fancy buying new wheels yet as these are still working.
Has anyone does Chung testing on wider rim vs narrow rim?
That’s narrow enough where I would consider this more of a compatibility question than a performance question… To directly answer your question, though it has been studied!
50mm would work, but you would likely need to run a higher pressure than is ideal to keep the tire from rolling in the corners. I think people forget/don’t know that the upper limit of how wide a tire can be is much further than modern news/trends would have you think. I used to run ikon 2.35s that measured almost 2.4 on 21.5mm mtb rims and rode them everywhere from super tame XC to black diamond bike park trails.
It may not be optimal for handling, aerodynamics, or rolling resistance, but it will definitely work.
I was thinking that. I’m sure my old xc wheels were around 20 mm running 2.1 and 2.2 inch tyres. I wasnt as fussed about optimisation back then so never thought about it. Reading this I was getting worried about needing modern rims all ill be 10 watts down. I will look into keeping the hubs and relacing onto some mtb rims
I’m sure there might be reasons not to do this, but here’s the setup I run for more extreme “gravel” (class 3 and 4 according to the 1-4 system): a drop bar hardtail.
Lynskey GR300
I9 650b wheels
Conti Race King 27.5 x 2,2 in the front (this fits in a Rockshox Rudy Ultimate)
Schwalbe Thunder Burt 27.5 x 2.1
The RK has slightly better grip than the TB, so I can hold the line on faster descents.
While it’s mainly for riding on light MTB trails, it does double duty as a backup/winter road bike.
