If wide low pressure tires are “Faster”, Why do I always feel like I need extra what’s for the same speed? I always feel like I am in the mud
On road or gravel? What tires?
Gravel tires are not going to be as fast as a good road tire on a good road surface.
If wide low pressure tires are “Faster”, Why do I always feel like I need extra what’s for the same speed? I always feel like I am in the mud
Who is saying that wide low-pressure tires are “faster” and in what context? Not even Jan Heine claims that going wider than a 25 will speed you up on good roads; rather, his argument is that excessive width is no big deal, so you might as well err wide for comfort and versatility.
How wide are we talking about, how low-pressure are we talking about, what particular tires are we talking about? That last one is very important: the 52mm tires that are on my gravel bike right now are nearly 2mph faster on pavement than the 45mm tires that I’ve got laying around that I could swap in their place. Not because 52mm is a better width than 45mm for paved riding, but because the 52s are fast supple slicks whereas the 45s are a very beefy urban/mixed-surface tire.
Other factors like fit also matter, a lot. If you ride in less aggressive postures on your gravel bike than your road bike, your body will be creating a lot more aerodynamic drag at high speeds.
This. Tires make a huge difference. Try schwalbe g-one or michelin power gravel, these are fast and grippy enough.
I was on the road running 38mm maxxis Rambler tubeless at 40 psi, I am 195lbs
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I was on the road running 38mm maxxis Rambler tubeless at 40 psi, I am 195lbs
Although Maxxis are quite dominant in the MTB market, they haven’t figured out how to make even a mediocre tyre for the bitumen yet…
I have 2.1" Thunder Burts on my Frankenbike, and I’m impressed how well they buzz along on pavement for a knobbly tyre. Not road tyre fast, but good enough not to feel like a chore.
Those are very heavy tires, near enough 500g a piece from what I can find online, and you will feel the weight when accelerating. I got a used bike with 650bx47mm tires and they are a similar weight and the effect is noticeable. What is also noticeable is how well the extra weight helps maintain momentum when rolling over debris/bad roads.
Tire pressure is also a potential issue. I am fair bit lighter than you and 40psi is on the low side of what I would run on the road for that size of tire. Adding a bit more pressure will help accelerating on the road. I would think 45-50 psi would be better for good road conditions and around 20-30 off-road.
For you, optimal tyre on normal road is probably a light tyre around 25mm at around 100 PSI
Heavy 38mm tyres will always be slower on the road than this optimal config (more rolling losses, more weight, more aero penalty). But indeed 40 PSI might no be the optimal for these 38mm, and you can work on the pressure to find at least the optimal level to lower rolling losses for these 38mm tyres. It will never be as efficient as an optimal config, but could be better than your current config.
Although Maxxis are quite dominant in the MTB market, they haven’t figured out how to make even a mediocre tyre for the bitumen yet…
Really? I think the Rambler’s have won the Dirty Kanza 200 more than a couple of times.
https://www.cxmagazine.com/gravel-bike-cannondale-superx-2018-dirty-kanza-200-kaitie-keough-ted-king/8
Kind of have to define what slow is. I just started riding gravel a few months ago here in Kansas and ride with a lot of people that have done the DK200, DK100 etc. and most of them have 38 ish size tires around the 40 psi mark which is what I’m riding. I weight over 200 lbs and have my tires around 42 psi. But it also depends on type of gravel which can actually vary greatly even on a single ride.
I think your weight has to be taken into account while riding off-pavement when discussing rolling resistance. I ride cross and a fair bit of gravel, sand and dirt roads and am also around your weight (207 lbs) and I find that the contact patch size is driven by tire pressure, rider/bike total weight, tire casing suppleness and how soft or de-formable the surface ridden on is. All other things being equal except weight means that the higher weight will sink into a soft surface further and require greater power to plow through it. I did a muddy cross race 2 weeks ago and my power was significantly higher than a couple friends who are about 40 lbs lighter even though the mud was all but flat.
I think there are a couple ways to help this; ride a tire a few mm wider combined with a little less tire pressure will help the most. Also the tread pattern can effect the interaction with the surface. For instance in cross there are dedicated tires for the races with lots of sand, they have a low file tread and apparently break the surface tension of the sand less therefore don’t sink as much. Of course we have to pick tires that will deal with a mix of surfaces so there are always compromises.
rich
Rich - I’m about the same size and agree about wider tires but think bigger riders need to use slightly higher psi compared to our 150lbs friends when riding gravel, cross or mtb.
David K
This is expected and pretty normal. Even Ted King (2x DK 200 winner) says riding a heavier gravel bike, with heavier, much wider tires is going to make you much slower, or require much more effort to achieve similar speeds to the road bike. For me, the difference between the speeds I can maintain on my road bikes and my gravel bike is massive. Also I am not sure what gravel bike you are riding and the geometry but mine has a much more relaxed geometry than my two road race bikes. Trek Checkpoint SL vs Trek Madone 9 (H1) and S-Works Tarmac SL6. And also, are you using similar wheels? I would guess no. I absolutely freaken love gravel riding though.
I was on the road running 38mm maxxis Rambler tubeless at 40 psi, I am 195lbs
I haven’t seen any tires from Maxxis that have good rolling resistance. Independent testers over the last 15 years or so pushed the envelope for road tires and kept manufacturers honest, but hardly anyone tests offroad tires. And unfortunately Crr isn’t something you can really feel especially offroad, where it’s overwhelmed by the resistance of the ground. So really crappy Crr tires can become popular if they have good grip, longevity, and puncture resistance.
Not the best tests, but the only ones I’ve seen: https://www.bicyclerollingresistance.com/mtb-reviews
Notice that all the good ones are made by Schwalbe or Continental. All the Maxxis tires suck.
Although Maxxis are quite dominant in the MTB market, they haven’t figured out how to make even a mediocre tyre for the bitumen yet…
Really? I think the Rambler’s have won the Dirty Kanza 200 more than a couple of times.
https://www.cxmagazine.com/gravel-bike-cannondale-superx-2018-dirty-kanza-200-kaitie-keough-ted-king/8
Completely irrelevant. DK has almost no ‘bitumen’
On the gravel, I dunno. Around here I find people ride shorter ride times or tend to stop after segments a lot more than on the road. Meaning it’s rest and repeat. I ride tempo or SS for a few hours at a time. So, yeah, my speed are going to easily be slower than my compadres who go in and ride gravel all-out and then rest.
But yeah, tires and pressures do matter…a lot.
Slow compared to what? road 22mm?
I was on the road running 38mm maxxis Rambler tubeless at 40 psi, I am 195lbs
I haven’t seen any tires from Maxxis that have good rolling resistance. Independent testers over the last 15 years or so pushed the envelope for road tires and kept manufacturers honest, but hardly anyone tests offroad tires. And unfortunately Crr isn’t something you can really feel especially offroad, where it’s overwhelmed by the resistance of the ground. So really crappy Crr tires can become popular if they have good grip, longevity, and puncture resistance.
Not the best tests, but the only ones I’ve seen: https://www.bicyclerollingresistance.com/mtb-reviews
Notice that all the good ones are made by Schwalbe or Continental. All the Maxxis tires suck.
Their results nor methodology are public knowledge but when it comes to pure off-road performance, the Swiss national federation tested rolling resistance quite extensively before opting to switch Nino Schurter over from his trademark custom Dugast tubs to Maxxis Aspens ahead of the Rio Olympics. They certainly had any Schwalbe, Continental or other option at hand to consider. I don’t know if roller testing is directly applicable to off-road tyre performance?
Of course you’re right! You have to find that balance between pressure comfort and traction that works for whatever it is you’re doing. I’m sorry I left that out and thanks for catching it!