Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a double down tire I fully cracked my wheel. Are most of yall running inserts, or are the i9 aluminum trail wheels just junk?
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a...
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a double down tire I fully cracked my wheel. Are most of yall running inserts, or are the i9 aluminum trail wheels just junk?
Any opinions on the AL MK4 Flow rim?
Always look at rider weight when looking at tire pressure. Nino Schurter weighs 150 lbs. he can get away with 17psi. I weigh 200. I cannot get away with 17psi.
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a...
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a double down tire I fully cracked my wheel. Are most of yall running inserts, or are the i9 aluminum trail wheels just junk?
Always look at rider weight when looking at tire pressure. Nino Schurter weighs 150 lbs. he can get away with 17psi. I weigh 200. I cannot...
Always look at rider weight when looking at tire pressure. Nino Schurter weighs 150 lbs. he can get away with 17psi. I weigh 200. I cannot get away with 17psi.
tire carcass matters a lot, also. radials generally need more air than bias ply.
inserts won't save a rim if you have a very hard hit as the spokes are going to give and then the rim breaks, then you're a sad person who was riding too little air pressure for too little gain.
even if you've bought a wheel with lifetime NQA warranty it will get old waiting on replacements, and also expensive if their warranty says rim only and you rebuild the wheel.
me? 84kg, no inserts, 25psi rear for trail only. rocky dh, 28+. zero rear wheels destroyed, and I have broken single spokes a number of times.
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a...
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a double down tire I fully cracked my wheel. Are most of yall running inserts, or are the i9 aluminum trail wheels just junk?
Any opinions on the AL MK4 Flow rim?
I weigh <155 lbs and local trails don't have many rocks.
Idk whats going on in this forum lately. Amaury: I'm using radials. Schwalbe: our riders are all using radials. Us: no one's using radials. My personal experience, riding them in...
Idk whats going on in this forum lately.
Amaury: I'm using radials.
Schwalbe: our riders are all using radials.
Us: no one's using radials.
My personal experience, riding them in every condition imaginable, including snow: the biggest improvement in mountain bike technology since we figured out 64 degree HTA could apply to non DH bikes.
If you look at the hot patch of the Schwalbe sponsored pros, they almost never include the "Radial" text. Another telltale sign when they run "diagnonal" tires is the tread pattern of the Tacky Chan is different in diagonal vs. radial. I've seen them running radials more often in Enduro but big guys like Richie are never on radials.
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a...
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a double down tire I fully cracked my wheel. Are most of yall running inserts, or are the i9 aluminum trail wheels just junk?
Any opinions on the AL MK4 Flow rim?
There is a lot of factors, and I can't comment on that rim. That said I've found the Wolftooth calculator to be an accurate tool for me and simplifies it. It takes into account the bike weight, casing and type of riding. For me I err on the side of caution and put in "enduro, steeps, rocks" for my riding conditions as I live in Colorado (its rocky) and I enjoy pulling for the blind double last minute and sometimes it doesn't work (dumb lines). If your denting rims you need to up the pressure, even 1-2 will do a lot. If you don't like that pressure, up the casing. I wouldn't worry about inserts. When I ran them (I don't now) I dented more rims than ever as I thought "oh I can run less pressure", but then I would end up with slashes anyways and carrying a messy pool noodle on the trail and swearing at it installing the repaired or new tire.
The tool for me changes my Enduro bike from 25 psi with (enduro) riding conditions to 19 with XC/Trail Soft. (thick casing, 192 total gear weight). I would never go that low, and have found at lower pressures on tracks that are fast with catch berms the tire roll is no good or I burp the tire. If it is an all natural, slower non rocky trail sure, but I don't like those trails. And it basically says I would need to run 2-3 PSI with thin casing, which probably sounds right.
Idk whats going on in this forum lately. Amaury: I'm using radials. Schwalbe: our riders are all using radials. Us: no one's using radials. My personal experience, riding them in...
Idk whats going on in this forum lately.
Amaury: I'm using radials.
Schwalbe: our riders are all using radials.
Us: no one's using radials.
My personal experience, riding them in every condition imaginable, including snow: the biggest improvement in mountain bike technology since we figured out 64 degree HTA could apply to non DH bikes.
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best choice for someone depends on a number of factors. In the summer when I'm hitting higher speeds I just prefer the support of a standard casing. In the winter when things are wet I find the radials work better because I need all the compliance/grip I can get. Horses for courses.
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best...
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best choice for someone depends on a number of factors. In the summer when I'm hitting higher speeds I just prefer the support of a standard casing. In the winter when things are wet I find the radials work better because I need all the compliance/grip I can get. Horses for courses.
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation has a cost, after all.
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best...
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best choice for someone depends on a number of factors. In the summer when I'm hitting higher speeds I just prefer the support of a standard casing. In the winter when things are wet I find the radials work better because I need all the compliance/grip I can get. Horses for courses.
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation...
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation has a cost, after all.
and DH pros are trying to go faster.
Could you please share links for where people have tested the rolling resistance of radial tires vs bias ply? Haven't seen that yet.
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best...
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best choice for someone depends on a number of factors. In the summer when I'm hitting higher speeds I just prefer the support of a standard casing. In the winter when things are wet I find the radials work better because I need all the compliance/grip I can get. Horses for courses.
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation...
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation has a cost, after all.
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best...
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best choice for someone depends on a number of factors. In the summer when I'm hitting higher speeds I just prefer the support of a standard casing. In the winter when things are wet I find the radials work better because I need all the compliance/grip I can get. Horses for courses.
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation...
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation has a cost, after all.
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation...
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation has a cost, after all.
That's the one. It was even done in Schwalbe's own lab using their equipment.
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for measuring any tire) and with all tires inflated to the same pressures (which is bad for measuring radial vs. bias ply tires).
Measuring rolling resistance on a large steel drum is like picking tires based on how cool the patch on the sidewall looks. And this section in their article about tire pressure proves that the methodology is whack. They found the same results for all brands of DH tires, too (Conti, Schwalbe, Specialized):
"The biggest surprise in our test came from the MAXXIS ASSEGAI: despite identical dimensions and rubber compound, the DH casing version rolls better than the Doubledown. One possible explanation: the DH casing features a coarser 60 TPI fabric, whereas the Doubledown uses a finer 120 TPI weave. The coarser DH fabric might offer more deformation resistance, causing it to flex less under the set pressure of 1.5 bar – meaning less energy is lost to deformation. However, this “phenomenon” can’t be transferred one-to-one to real-world trail riding: in reality, a DH casing would typically be run at a lower pressure – one of its core advantages. That, in turn, would increase rolling resistance again."
The DH tires measured as lower rolling resistance than the lighter casing tires because on a steel drum the faster tire is the hardest tire. A DH tire with 1.5 bar is harder than a single ply or dual 120 tpi tire, so it's "faster." This is nonsense, for the exact reason listed in the paragraph above.
Are there any radial vs. bias ply tests that don't use a steel drum, or that vary tire pressure to reflect the manufacturer's own recommendations?
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for...
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for measuring any tire) and with all tires inflated to the same pressures (which is bad for measuring radial vs. bias ply tires).
Measuring rolling resistance on a large steel drum is like picking tires based on how cool the patch on the sidewall looks. And this section in their article about tire pressure proves that the methodology is whack. They found the same results for all brands of DH tires, too (Conti, Schwalbe, Specialized):
"The biggest surprise in our test came from the MAXXIS ASSEGAI: despite identical dimensions and rubber compound, the DH casing version rolls better than the Doubledown. One possible explanation: the DH casing features a coarser 60 TPI fabric, whereas the Doubledown uses a finer 120 TPI weave. The coarser DH fabric might offer more deformation resistance, causing it to flex less under the set pressure of 1.5 bar – meaning less energy is lost to deformation. However, this “phenomenon” can’t be transferred one-to-one to real-world trail riding: in reality, a DH casing would typically be run at a lower pressure – one of its core advantages. That, in turn, would increase rolling resistance again."
The DH tires measured as lower rolling resistance than the lighter casing tires because on a steel drum the faster tire is the hardest tire. A DH tire with 1.5 bar is harder than a single ply or dual 120 tpi tire, so it's "faster." This is nonsense, for the exact reason listed in the paragraph above.
Are there any radial vs. bias ply tests that don't use a steel drum, or that vary tire pressure to reflect the manufacturer's own recommendations?
How would you set it up to be representative? I know Vital did a rolling resistance test several years ago, but it was rolling down a straight section of asphalt and timing them. Not sure asphalt is better than a steel drum. The RojoDH guy posting on this forum does timed laps at a bike park comparing front tires, but that ends up including line choice, etc. and each time it's new tire vs. Assegai.
Schwalbe doesn't even provide any specific guidance on how much higher to run their radials other than a vague statement that riders often run slightly higher pressures than normal. If the argument is that you can run them higher pressure so that they'd have less rolling resistance, then you'd also trade off some of that added grip. We've seen lots of posts by users here stating that they increase pressures by anywhere from 5% - 30% from their normal pressures, clearly no hard and fast amount you could assume for testing.
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for...
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for measuring any tire) and with all tires inflated to the same pressures (which is bad for measuring radial vs. bias ply tires).
Measuring rolling resistance on a large steel drum is like picking tires based on how cool the patch on the sidewall looks. And this section in their article about tire pressure proves that the methodology is whack. They found the same results for all brands of DH tires, too (Conti, Schwalbe, Specialized):
"The biggest surprise in our test came from the MAXXIS ASSEGAI: despite identical dimensions and rubber compound, the DH casing version rolls better than the Doubledown. One possible explanation: the DH casing features a coarser 60 TPI fabric, whereas the Doubledown uses a finer 120 TPI weave. The coarser DH fabric might offer more deformation resistance, causing it to flex less under the set pressure of 1.5 bar – meaning less energy is lost to deformation. However, this “phenomenon” can’t be transferred one-to-one to real-world trail riding: in reality, a DH casing would typically be run at a lower pressure – one of its core advantages. That, in turn, would increase rolling resistance again."
The DH tires measured as lower rolling resistance than the lighter casing tires because on a steel drum the faster tire is the hardest tire. A DH tire with 1.5 bar is harder than a single ply or dual 120 tpi tire, so it's "faster." This is nonsense, for the exact reason listed in the paragraph above.
Are there any radial vs. bias ply tests that don't use a steel drum, or that vary tire pressure to reflect the manufacturer's own recommendations?
completely agreed, trails are not at all the same but even groomed flow isn't a steel drum. agreed on pressures also but since you're not riding a trail, where you would set pressure based on rider weight, preference / trail feel etc then I guess that leaves you with making them all the same.
also, some of the outliers feel weird, like the assegai 3CT consuming less watts than the dissector 3CT.
there also was a timed lap test with radials vs bias ply but my Google-foo must be weak today, I can't find it.
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for...
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for measuring any tire) and with all tires inflated to the same pressures (which is bad for measuring radial vs. bias ply tires).
Measuring rolling resistance on a large steel drum is like picking tires based on how cool the patch on the sidewall looks. And this section in their article about tire pressure proves that the methodology is whack. They found the same results for all brands of DH tires, too (Conti, Schwalbe, Specialized):
"The biggest surprise in our test came from the MAXXIS ASSEGAI: despite identical dimensions and rubber compound, the DH casing version rolls better than the Doubledown. One possible explanation: the DH casing features a coarser 60 TPI fabric, whereas the Doubledown uses a finer 120 TPI weave. The coarser DH fabric might offer more deformation resistance, causing it to flex less under the set pressure of 1.5 bar – meaning less energy is lost to deformation. However, this “phenomenon” can’t be transferred one-to-one to real-world trail riding: in reality, a DH casing would typically be run at a lower pressure – one of its core advantages. That, in turn, would increase rolling resistance again."
The DH tires measured as lower rolling resistance than the lighter casing tires because on a steel drum the faster tire is the hardest tire. A DH tire with 1.5 bar is harder than a single ply or dual 120 tpi tire, so it's "faster." This is nonsense, for the exact reason listed in the paragraph above.
Are there any radial vs. bias ply tests that don't use a steel drum, or that vary tire pressure to reflect the manufacturer's own recommendations?
I'm curious how much of it is actual increase in rolling resistance. On my local laps the radials can definitely feel slower, but when I check my actual downhill times there isn't much in it. And unless the climb is technical and/or wet I'm consistently faster on bias ply.
They give me plus tire vibes to some extent - what I'm feeling and what the clock says don't always line up.
I’m trying to figure out what Specialized tire combo to run. I already own a lightly used Cannibal - I’m a big fan of that tire. I could run that Cannibal up front with a Butcher, Eliminator, or another Cannibal in back.
But, would it be crazy to run the Cannibal in back with a Butcher Radial up front? I know the Cannibal is considered more aggressive than the Butcher, but I figure the radial casing could up the grip, particularly on more natural trails.
I’m trying to figure out what Specialized tire combo to run. I already own a lightly used Cannibal - I’m a big fan of that tire...
I’m trying to figure out what Specialized tire combo to run. I already own a lightly used Cannibal - I’m a big fan of that tire. I could run that Cannibal up front with a Butcher, Eliminator, or another Cannibal in back.
But, would it be crazy to run the Cannibal in back with a Butcher Radial up front? I know the Cannibal is considered more aggressive than the Butcher, but I figure the radial casing could up the grip, particularly on more natural trails.
What makes the Cannibal more aggressive?
More knobs? Different casing?
TBH I'm not experienced with Spesh tyres, hence the questions.
I'd have thought less knobs means more aggressive...
I’m trying to figure out what Specialized tire combo to run. I already own a lightly used Cannibal - I’m a big fan of that tire...
I’m trying to figure out what Specialized tire combo to run. I already own a lightly used Cannibal - I’m a big fan of that tire. I could run that Cannibal up front with a Butcher, Eliminator, or another Cannibal in back.
But, would it be crazy to run the Cannibal in back with a Butcher Radial up front? I know the Cannibal is considered more aggressive than the Butcher, but I figure the radial casing could up the grip, particularly on more natural trails.
nah not crazy at all to try since you already own the cannibal.
if you need more climbing and braking traction than the eliminator IMHO you can do another butcher, cannibal, or another brand entirely.
nah not crazy at all to try since you already own the cannibal.if you need more climbing and braking traction than the eliminator IMHO you can...
nah not crazy at all to try since you already own the cannibal.
if you need more climbing and braking traction than the eliminator IMHO you can do another butcher, cannibal, or another brand entirely.
hmm, although T9 does wear super fast on the rear in my experience. I think the specialized bikes that come stock with double butcher have a T7 in the back.
I’m trying to figure out what Specialized tire combo to run. I already own a lightly used Cannibal - I’m a big fan of that tire...
I’m trying to figure out what Specialized tire combo to run. I already own a lightly used Cannibal - I’m a big fan of that tire. I could run that Cannibal up front with a Butcher, Eliminator, or another Cannibal in back.
But, would it be crazy to run the Cannibal in back with a Butcher Radial up front? I know the Cannibal is considered more aggressive than the Butcher, but I figure the radial casing could up the grip, particularly on more natural trails.
I've run Cannibal front and rear and cannibal front with eliminator rear (my fav). I wish they made the cannibal in grid trail casing, I'd never run a butcher again
Idk whats going on in this forum lately. Amaury: I'm using radials. Schwalbe: our riders are all using radials. Us: no one's using radials. My personal experience, riding them in...
Idk whats going on in this forum lately.
Amaury: I'm using radials.
Schwalbe: our riders are all using radials.
Us: no one's using radials.
My personal experience, riding them in every condition imaginable, including snow: the biggest improvement in mountain bike technology since we figured out 64 degree HTA could apply to non DH bikes.
How much do you weight and what pressure are you running?
How much do you weight and what pressure are you running?
I have found the Wolf Tooth Calculator for casing type "Radial" was a good starting place. I used the actual measured sidewall width, in my previous post was 2.3 at the casing, not 2.5" at knobs and stated. I haven't changed from what they have unless its wet and I reduce a PSI.
Asking someone else isn't perfect. Their bike could weight more than yours, they could be 27 vs 29, they could ride different types of soil and all of that factors into the recommended pressure and can be pretty drastic.
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for...
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for measuring any tire) and with all tires inflated to the same pressures (which is bad for measuring radial vs. bias ply tires).
Measuring rolling resistance on a large steel drum is like picking tires based on how cool the patch on the sidewall looks. And this section in their article about tire pressure proves that the methodology is whack. They found the same results for all brands of DH tires, too (Conti, Schwalbe, Specialized):
"The biggest surprise in our test came from the MAXXIS ASSEGAI: despite identical dimensions and rubber compound, the DH casing version rolls better than the Doubledown. One possible explanation: the DH casing features a coarser 60 TPI fabric, whereas the Doubledown uses a finer 120 TPI weave. The coarser DH fabric might offer more deformation resistance, causing it to flex less under the set pressure of 1.5 bar – meaning less energy is lost to deformation. However, this “phenomenon” can’t be transferred one-to-one to real-world trail riding: in reality, a DH casing would typically be run at a lower pressure – one of its core advantages. That, in turn, would increase rolling resistance again."
The DH tires measured as lower rolling resistance than the lighter casing tires because on a steel drum the faster tire is the hardest tire. A DH tire with 1.5 bar is harder than a single ply or dual 120 tpi tire, so it's "faster." This is nonsense, for the exact reason listed in the paragraph above.
Are there any radial vs. bias ply tests that don't use a steel drum, or that vary tire pressure to reflect the manufacturer's own recommendations?
How would you set it up to be representative? I know Vital did a rolling resistance test several years ago, but it was rolling down a...
How would you set it up to be representative? I know Vital did a rolling resistance test several years ago, but it was rolling down a straight section of asphalt and timing them. Not sure asphalt is better than a steel drum. The RojoDH guy posting on this forum does timed laps at a bike park comparing front tires, but that ends up including line choice, etc. and each time it's new tire vs. Assegai.
Schwalbe doesn't even provide any specific guidance on how much higher to run their radials other than a vague statement that riders often run slightly higher pressures than normal. If the argument is that you can run them higher pressure so that they'd have less rolling resistance, then you'd also trade off some of that added grip. We've seen lots of posts by users here stating that they increase pressures by anywhere from 5% - 30% from their normal pressures, clearly no hard and fast amount you could assume for testing.
I really liked the Vital rolling resistance test methods, as long as wind isn't a factor. It holds a lot of variables constant, and an asphalt road is actually more similar to a smooth section of trail than either are to a smooth metal drum.
The whole road bike tire universe exploded when Bicycle Quarterly started doing tests on real asphalt roads using standardized power efforts using crankarm power meters. It turned all of the conventional wisdom on it's head. Doing something like that with a flat lap or section of trail at a constant power effort on an MTB would be good, too, as long as you really are pedaling all the time, no coasting, and you're able to stare at your power meter the whole time to maintain a constant effort. I don't like the idea of using a hill climb because, while it makes it easier to hold a constant power, it also significantly reduces the bicycle velocity, which reduces rolling resistance and makes it harder to draw conclusions from the data.
Bit of a thread de-rail, but I keep seeing people running like 22 psi in the rear wheel. Last time I tired 24 PSI on a double down tire I fully cracked my wheel. Are most of yall running inserts, or are the i9 aluminum trail wheels just junk?
Any opinions on the AL MK4 Flow rim?
Always look at rider weight when looking at tire pressure. Nino Schurter weighs 150 lbs. he can get away with 17psi. I weigh 200. I cannot get away with 17psi.
tire carcass matters a lot, also. radials generally need more air than bias ply.
inserts won't save a rim if you have a very hard hit as the spokes are going to give and then the rim breaks, then you're a sad person who was riding too little air pressure for too little gain.
even if you've bought a wheel with lifetime NQA warranty it will get old waiting on replacements, and also expensive if their warranty says rim only and you rebuild the wheel.
me? 84kg, no inserts, 25psi rear for trail only. rocky dh, 28+. zero rear wheels destroyed, and I have broken single spokes a number of times.
I weigh <155 lbs and local trails don't have many rocks.
If you look at the hot patch of the Schwalbe sponsored pros, they almost never include the "Radial" text. Another telltale sign when they run "diagnonal" tires is the tread pattern of the Tacky Chan is different in diagonal vs. radial. I've seen them running radials more often in Enduro but big guys like Richie are never on radials.
There is a lot of factors, and I can't comment on that rim. That said I've found the Wolftooth calculator to be an accurate tool for me and simplifies it. It takes into account the bike weight, casing and type of riding. For me I err on the side of caution and put in "enduro, steeps, rocks" for my riding conditions as I live in Colorado (its rocky) and I enjoy pulling for the blind double last minute and sometimes it doesn't work (dumb lines). If your denting rims you need to up the pressure, even 1-2 will do a lot. If you don't like that pressure, up the casing. I wouldn't worry about inserts. When I ran them (I don't now) I dented more rims than ever as I thought "oh I can run less pressure", but then I would end up with slashes anyways and carrying a messy pool noodle on the trail and swearing at it installing the repaired or new tire.
The tool for me changes my Enduro bike from 25 psi with (enduro) riding conditions to 19 with XC/Trail Soft. (thick casing, 192 total gear weight). I would never go that low, and have found at lower pressures on tracks that are fast with catch berms the tire roll is no good or I burp the tire. If it is an all natural, slower non rocky trail sure, but I don't like those trails. And it basically says I would need to run 2-3 PSI with thin casing, which probably sounds right.
I'm not saying no one should use them. I'm just saying like everything else they have pros and cons so whether or not they're the best choice for someone depends on a number of factors. In the summer when I'm hitting higher speeds I just prefer the support of a standard casing. In the winter when things are wet I find the radials work better because I need all the compliance/grip I can get. Horses for courses.
pretty sure that every time radials have been tested against bias ply they do in fact roll slower. the additional surface area contact and carcass deformation has a cost, after all.
and DH pros are trying to go faster.
Could you please share links for where people have tested the rolling resistance of radial tires vs bias ply? Haven't seen that yet.
Sources are for squares. This is 2026 Robot.
I believe it’s the enduro mag test of tyres
that's the easiest one to find. magic mary was tested in ... 4 variants, I think?
https://enduro-mtb.com/en/mtb-tire-test-weight-rolling-resistance-punct…
That's the one. It was even done in Schwalbe's own lab using their equipment.
The test methodology in that Enduro MTB test leaves a lot to be desired. They measured the tires' rolling resistance on a steel drum (bad for measuring any tire) and with all tires inflated to the same pressures (which is bad for measuring radial vs. bias ply tires).
Measuring rolling resistance on a large steel drum is like picking tires based on how cool the patch on the sidewall looks. And this section in their article about tire pressure proves that the methodology is whack. They found the same results for all brands of DH tires, too (Conti, Schwalbe, Specialized):
"The biggest surprise in our test came from the MAXXIS ASSEGAI: despite identical dimensions and rubber compound, the DH casing version rolls better than the Doubledown. One possible explanation: the DH casing features a coarser 60 TPI fabric, whereas the Doubledown uses a finer 120 TPI weave. The coarser DH fabric might offer more deformation resistance, causing it to flex less under the set pressure of 1.5 bar – meaning less energy is lost to deformation. However, this “phenomenon” can’t be transferred one-to-one to real-world trail riding: in reality, a DH casing would typically be run at a lower pressure – one of its core advantages. That, in turn, would increase rolling resistance again."
The DH tires measured as lower rolling resistance than the lighter casing tires because on a steel drum the faster tire is the hardest tire. A DH tire with 1.5 bar is harder than a single ply or dual 120 tpi tire, so it's "faster." This is nonsense, for the exact reason listed in the paragraph above.
Are there any radial vs. bias ply tests that don't use a steel drum, or that vary tire pressure to reflect the manufacturer's own recommendations?
How would you set it up to be representative? I know Vital did a rolling resistance test several years ago, but it was rolling down a straight section of asphalt and timing them. Not sure asphalt is better than a steel drum. The RojoDH guy posting on this forum does timed laps at a bike park comparing front tires, but that ends up including line choice, etc. and each time it's new tire vs. Assegai.
Schwalbe doesn't even provide any specific guidance on how much higher to run their radials other than a vague statement that riders often run slightly higher pressures than normal. If the argument is that you can run them higher pressure so that they'd have less rolling resistance, then you'd also trade off some of that added grip. We've seen lots of posts by users here stating that they increase pressures by anywhere from 5% - 30% from their normal pressures, clearly no hard and fast amount you could assume for testing.
completely agreed, trails are not at all the same but even groomed flow isn't a steel drum. agreed on pressures also but since you're not riding a trail, where you would set pressure based on rider weight, preference / trail feel etc then I guess that leaves you with making them all the same.
also, some of the outliers feel weird, like the assegai 3CT consuming less watts than the dissector 3CT.
there also was a timed lap test with radials vs bias ply but my Google-foo must be weak today, I can't find it.
I'm curious how much of it is actual increase in rolling resistance. On my local laps the radials can definitely feel slower, but when I check my actual downhill times there isn't much in it. And unless the climb is technical and/or wet I'm consistently faster on bias ply.
They give me plus tire vibes to some extent - what I'm feeling and what the clock says don't always line up.
IF DH front tires are all you're concerned with, this guy has done some interesting work:
https://www.youtube.com/@RoJoDH
I’m trying to figure out what Specialized tire combo to run. I already own a lightly used Cannibal - I’m a big fan of that tire. I could run that Cannibal up front with a Butcher, Eliminator, or another Cannibal in back.
But, would it be crazy to run the Cannibal in back with a Butcher Radial up front? I know the Cannibal is considered more aggressive than the Butcher, but I figure the radial casing could up the grip, particularly on more natural trails.
What makes the Cannibal more aggressive?
More knobs? Different casing?
TBH I'm not experienced with Spesh tyres, hence the questions.
I'd have thought less knobs means more aggressive...
nah not crazy at all to try since you already own the cannibal.
if you need more climbing and braking traction than the eliminator IMHO you can do another butcher, cannibal, or another brand entirely.
hmm, although T9 does wear super fast on the rear in my experience. I think the specialized bikes that come stock with double butcher have a T7 in the back.
I've run Cannibal front and rear and cannibal front with eliminator rear (my fav). I wish they made the cannibal in grid trail casing, I'd never run a butcher again
Cannibal rear with a hillbilly up front
How much do you weight and what pressure are you running?
I have found the Wolf Tooth Calculator for casing type "Radial" was a good starting place. I used the actual measured sidewall width, in my previous post was 2.3 at the casing, not 2.5" at knobs and stated. I haven't changed from what they have unless its wet and I reduce a PSI.
Asking someone else isn't perfect. Their bike could weight more than yours, they could be 27 vs 29, they could ride different types of soil and all of that factors into the recommended pressure and can be pretty drastic.
I really liked the Vital rolling resistance test methods, as long as wind isn't a factor. It holds a lot of variables constant, and an asphalt road is actually more similar to a smooth section of trail than either are to a smooth metal drum.
The whole road bike tire universe exploded when Bicycle Quarterly started doing tests on real asphalt roads using standardized power efforts using crankarm power meters. It turned all of the conventional wisdom on it's head. Doing something like that with a flat lap or section of trail at a constant power effort on an MTB would be good, too, as long as you really are pedaling all the time, no coasting, and you're able to stare at your power meter the whole time to maintain a constant effort. I don't like the idea of using a hill climb because, while it makes it easier to hold a constant power, it also significantly reduces the bicycle velocity, which reduces rolling resistance and makes it harder to draw conclusions from the data.
https://bikerumor.com/maxxis-debuts-a-new-minion-dhx-for-dry-plus-all-new-dh-casing-for-all-first-riding-review/
200 pounds geared up, between 25-30 psi depending
I also think that radial tires are the biggest innovation in MTB technology since modern geo.
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