Tire questions for commuting
05-19-10 | 06:58 PM
#1
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Tire questions for commuting
1. Whats faster?
slick tires at 26 * 1.5 or 26 * 2.125
assuming they are pumped at their optimal psi?
2. Are 700c wheels faster than slicks MTB?
3. Does a larger contact patch have a greater rolling resistance or lesser?
I am going to set up another bike and unsure whether i should go the mtb route or 700c direction.
slick tires at 26 * 1.5 or 26 * 2.125
assuming they are pumped at their optimal psi?
2. Are 700c wheels faster than slicks MTB?
3. Does a larger contact patch have a greater rolling resistance or lesser?
I am going to set up another bike and unsure whether i should go the mtb route or 700c direction.
05-19-10 | 07:21 PM
#2
cyclepath
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Bikes: 2005 Trek Pilot 5.0, 2001 Specialized Sirrus Pro, Kona Lava Dome, Raleigh hardtail converted to commuter, 87 Takara steel road bike, 2008 Trek Soho
the thinner the tire and the smaller the contact patch, the faster the tire, right? Or is this a trick question?
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05-19-10 | 07:50 PM
#4
cyclepath
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Bikes: 2005 Trek Pilot 5.0, 2001 Specialized Sirrus Pro, Kona Lava Dome, Raleigh hardtail converted to commuter, 87 Takara steel road bike, 2008 Trek Soho
With 700c tires you can go a bit thinner than with a 26 inch. They do make 1 inch slicks though that will roll a mt bike pretty good. When you set the bike up, consider gearing as well. Maybe that should be the first consideration.
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05-19-10 | 07:56 PM
#5
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I don't think it's just the contact patch that matters. I was given to believe that the sidewall flexibility matters too.
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05-19-10 | 08:13 PM
#6
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Seem to suggest that thinner is better?
05-19-10 | 08:49 PM
#7
Lumens For Life
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Bikes: 1989 Nishiki Ariel, 24" Elf Doublecross, 80's(?) Schwinn Traveler, soon a Motobecane Fantom Cross Uno
Quoted from the Rivendell website.... https://www.rivbike.com/article/components/tires
Personally i ride on 26 x 1.75 Michelin Pilot City tires and they are awesome..!!
https://www.michelinbicycletire.com/m...pilotcity.view
The biggest, best bargain in bicycles is air in the tires, yet for the last twenty years or so there's been a heinous trend toward tires with lower and lower volumes. This is bad because these skinny tires need to be pumped up to outrageous pressures like 110 to 145 psi just to protect the tubes from pinch flats and the rims from flat spots. Such high pressure tires roll fast on smooth roads, but as soon as the road turns slightly rough or slightly wet, they're uncomfortable and slippery.
The whole idea of hard skinnies is speed, but it doesn't work that way. Speed comes from fitness, not hard & skinny tires.
It's better to ride on higher volume tires that can be ridden at lower, more comfortable, and grippier pressures.
Bigger softer tires are often faster than hard skinnies, anyway. When a hard tire hits a bump in the road, two things happen. First, the bike is jolted upward, slowing its forward progress. Second, you-the-rider are jostled at least to the point of having to recover from the feel of the bump, and maybe even to the point where you lose control. Certainly, if you hit a bump as you're cornering at high speed, the wheel will likely lose the ground, and you'll go down.
With a softer tire it's a different story. Instead of the bike and wheel getting bounced, the larger, softer tire deforms and it smacks the bump (or edge of the pothole), and the tire rolls right over it, continuing its forward motion nearly unimpeded. Around the corner, you maintain traction. You can relax more because, as you ride in and out of the shadows on an unfamiliar road, or at night, you know your tires are there as a buffer for you.
The whole idea of hard skinnies is speed, but it doesn't work that way. Speed comes from fitness, not hard & skinny tires.
It's better to ride on higher volume tires that can be ridden at lower, more comfortable, and grippier pressures.
Bigger softer tires are often faster than hard skinnies, anyway. When a hard tire hits a bump in the road, two things happen. First, the bike is jolted upward, slowing its forward progress. Second, you-the-rider are jostled at least to the point of having to recover from the feel of the bump, and maybe even to the point where you lose control. Certainly, if you hit a bump as you're cornering at high speed, the wheel will likely lose the ground, and you'll go down.
With a softer tire it's a different story. Instead of the bike and wheel getting bounced, the larger, softer tire deforms and it smacks the bump (or edge of the pothole), and the tire rolls right over it, continuing its forward motion nearly unimpeded. Around the corner, you maintain traction. You can relax more because, as you ride in and out of the shadows on an unfamiliar road, or at night, you know your tires are there as a buffer for you.
https://www.michelinbicycletire.com/m...pilotcity.view
05-19-10 | 08:49 PM
#8
Large and in charge
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Bikes: At one point it was a Trek 700 something. Now it have Velocity Psycho wheels, a tape job. Thumb shifters (Shimano Deore). Corncob grouping, and drop bar ends all wrapped up in tape.
Tire compound has much more to do with rolling resistance in my experience. The tougher the rubber the less it deforms. For example, in 26inches, I found the Marathon plus at 1.75 and 70psi ran much faster than an Armadillo 1.5 at 90psi. The rubber is just better.
In regards to 26 vs 700c. I think the weight of the rim and the bikes geometry have a much bigger impact that the wheel size.
These are just all personal opinions based on what little experience I have.
In regards to 26 vs 700c. I think the weight of the rim and the bikes geometry have a much bigger impact that the wheel size.
These are just all personal opinions based on what little experience I have.
05-20-10 | 08:15 AM
#9
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after thousands and thousands of miles on 700c tires ranging from 25mm to 40mm i personally believe that the difference in speed is insubstantial. just ride the tires you want and enjoy! personally, i believe the fatter tires are more enjoyable for comfort reasons, but they're not significantly slower than skinny
05-20-10 | 08:46 AM
#10
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There are an awful lot of factors that need to be considered to get the precise, correct answer.
In my experience, tire weight matters more than rolling resistance. People will tell you tire weight only matters while you're accelerating, but since you're starting and stopping all the time on a typical commute, this matters.
Different tires will be faster under different conditions. Mountain bike racers use fat, knobby tires because it lets them ride faster. Road racers use slick, skinny tires because it lets them ride faster. The bottom line is, whatever tire you get, your fitness will determine the speed. The tire might make as much as a 10 percent difference.
In my experience, tire weight matters more than rolling resistance. People will tell you tire weight only matters while you're accelerating, but since you're starting and stopping all the time on a typical commute, this matters.
Different tires will be faster under different conditions. Mountain bike racers use fat, knobby tires because it lets them ride faster. Road racers use slick, skinny tires because it lets them ride faster. The bottom line is, whatever tire you get, your fitness will determine the speed. The tire might make as much as a 10 percent difference.
05-20-10 | 09:09 AM
#11
I am a caffine girl
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Just four letter: YMMV
Lots will depend on the road condition of your route, your weight and load you are carrying, how many hills and so on.
What I find better for me might be different for you. My road are all street road and mostly smooth enough to use 700x25. I'm light enough to go 23 if I want but with my load of my rack, bag, and pannier, I think a 23 might get out of round as compare to a 25 with the same PSI. If my road were rougher, than I may consider wider tire or even 26. Here is something to also think about, in a very steep hill, I can go faster and easier on a MTB 26 because of gearing and smaller diameter tire than I can on a 700 with the same daily load.....but on my light carbon bike with no load, I fly up those hills like a goat.
Confuse yet? Best thing to do is try different setup of bikes if you can so that you know what will be best bike for that route. Otherwise do the N+1 thing and you'll be cover for most scenerio.
Lots will depend on the road condition of your route, your weight and load you are carrying, how many hills and so on.
What I find better for me might be different for you. My road are all street road and mostly smooth enough to use 700x25. I'm light enough to go 23 if I want but with my load of my rack, bag, and pannier, I think a 23 might get out of round as compare to a 25 with the same PSI. If my road were rougher, than I may consider wider tire or even 26. Here is something to also think about, in a very steep hill, I can go faster and easier on a MTB 26 because of gearing and smaller diameter tire than I can on a 700 with the same daily load.....but on my light carbon bike with no load, I fly up those hills like a goat.
Confuse yet? Best thing to do is try different setup of bikes if you can so that you know what will be best bike for that route. Otherwise do the N+1 thing and you'll be cover for most scenerio.
05-20-10 | 09:41 AM
#12
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Each tire is different, but in general for street riding, I'd go for the narrower of those two option. Going all the way into racing-width tires will give you diminishing returns. Very small tires used in racing are preferred largely because of their cornering profile. You can lean hard into a high-speed turn, and there's no significant deflection in the tire, reducing the likelihood of wiping out. They're not really inherently faster simply by being small.
Low pressure tires increase sidewall flex (the major contributing factor in rolling resistance), which will rob you of more energy. Think of the difference it makes when you pump up your tires, that's what happens again when you move to a higher pressure. Pressure matters more than size, because carrying the same weight at the same pressure requires the same contact patch, regardless of how wide the tire is. Smaller contact patch is better simply because it's inherently indicative of how much the tire had to deflect to create the contact patch. All tires are round, all contact patches are flat.
700c wheels handle a bit differently (they feel all sporty-like
), and the tires made for them are typically higher pressure than 26" tires. They also change the properties of any given gear ratio, so the same gearing will feel different on a larger wheel. I like mine, and I'm just riding the stock 700x28s that came with the bike. But once you've gone to a slick tires, the actual performance advantage for daily use isn't huge, probably not enough to be worth a new bike to handle them.
Low pressure tires increase sidewall flex (the major contributing factor in rolling resistance), which will rob you of more energy. Think of the difference it makes when you pump up your tires, that's what happens again when you move to a higher pressure. Pressure matters more than size, because carrying the same weight at the same pressure requires the same contact patch, regardless of how wide the tire is. Smaller contact patch is better simply because it's inherently indicative of how much the tire had to deflect to create the contact patch. All tires are round, all contact patches are flat.
700c wheels handle a bit differently (they feel all sporty-like
), and the tires made for them are typically higher pressure than 26" tires. They also change the properties of any given gear ratio, so the same gearing will feel different on a larger wheel. I like mine, and I'm just riding the stock 700x28s that came with the bike. But once you've gone to a slick tires, the actual performance advantage for daily use isn't huge, probably not enough to be worth a new bike to handle them.
Last edited by neil; 05-20-10 at 09:49 AM.
05-20-10 | 09:44 AM
#13
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There is a lot of bad info or misleading info concerning tires and some of it is on that Rivandale site. You don't see competitive cyclist riding a mtb on 1.5 inch slicks so to say that using high pressure tires in a 23mm 700c wheels is misguided is in fact misinformation.
However, as a commuter or general purpose cyclist you do not need maximum performance, you need a "best compromise" and that brings up the question you asked. For myself, I would look at a bike with 700c wheels that could handle a range of tire widths in the 28 to 42mm range. A good multi surface tire like a Pasela in a 28 will roll cleanly and can be inflated to sufficient pressure to minimize pinch flatting and reduce roll resistance.
However, as a commuter or general purpose cyclist you do not need maximum performance, you need a "best compromise" and that brings up the question you asked. For myself, I would look at a bike with 700c wheels that could handle a range of tire widths in the 28 to 42mm range. A good multi surface tire like a Pasela in a 28 will roll cleanly and can be inflated to sufficient pressure to minimize pinch flatting and reduce roll resistance.
05-20-10 | 11:20 AM
#14
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A friend has an eBike that has a computer on it that can tell you exactly how many watts the motor is drawing at any given time. he says that 10 PSI difference in the tire makes a HUGE difference in the amount of energy required to push the bike at any given speed.
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05-20-10 | 11:22 AM
#15
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The Panaracer Pasela has thin sidewalls that make it feel more lively and faster over small bumps. It still has the kevlar belt under the tread for flat protection. I now have Continental Gatorskins 700 X 28. That also feel fast, but I dont think there is much difference in real performance. Specialized Armadillos definitely felt slow.
05-20-10 | 03:34 PM
#16
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Everyone seems to have nailed the factors contributing to ride feel and the relative speed per effort for different tires. The short answer being, a narrower tire doesn't guarantee higher speeds because the casing design, tread compound, and tread pattern all account for differences between tires.
Jan Heine did a great comparison of wider tires (from 25 to 42mm) in Bicycle Quarterly. Although the discussion was subjective, the overall gist is that even tires up to 37 and 42mm wide are not necessarily "slower" solely on merit of their width. A strong but flexible casing coupled with a durable tread compound, mounted with high enough pressure on a rim wide enough to keep sidewall deflection to a minimum will provide a smooth ride over rougher terrain, which increases speed in comparison to a narrower high-pressure tire in a similar situation.
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05-20-10 | 03:40 PM
#17
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On my road tires, there's only a slight perceived difference in effort required to maintain the same speed when going from 110 to 120psi.
05-20-10 | 05:29 PM
#18
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Bikes: Some bikes. Hell, they're all the same, ain't they?
Just to muddy this topic some more --
The newest, but separate, things in road bike tires and wheels are tubeless tires and wide rims.
The people who ride tubeless are saying that they can run lower pressures (like 90 psi instead of 110) and gain comfort and cornering grip while not losing efficiency or rim protection. They also are having fewer flats, probably mostly due to the sealant used, which both seals the bead and seals potential flats.
Wider rims, as they relate here, are as wide as the tires themselves -- about 23 mm instead of 19 mm like most road wheels. It's enough of a difference that the tires' sidewalls don't bulge out anymore. Owners tell of the same benefits as tubeless users, especially when it comes to fewer pinch flats, more consistent handling, and a nicer ride quality.
I think both of these approaches make sense. Car tires have been tubeless for a long, long time, and their normally straighter sidewalls don't give a squidgy feeling to handling. It's just that tubeless road bike tires are a recent development due to 1) sealant technology caught up with high air pressures; 2) change in cycling can be glacial sometimes; and 3) manufacturers need a New Product to sell. I haven't done either of these yet, though, mainly just because I got some nice regular wheels last summer.
The newest, but separate, things in road bike tires and wheels are tubeless tires and wide rims.
The people who ride tubeless are saying that they can run lower pressures (like 90 psi instead of 110) and gain comfort and cornering grip while not losing efficiency or rim protection. They also are having fewer flats, probably mostly due to the sealant used, which both seals the bead and seals potential flats.
Wider rims, as they relate here, are as wide as the tires themselves -- about 23 mm instead of 19 mm like most road wheels. It's enough of a difference that the tires' sidewalls don't bulge out anymore. Owners tell of the same benefits as tubeless users, especially when it comes to fewer pinch flats, more consistent handling, and a nicer ride quality.
I think both of these approaches make sense. Car tires have been tubeless for a long, long time, and their normally straighter sidewalls don't give a squidgy feeling to handling. It's just that tubeless road bike tires are a recent development due to 1) sealant technology caught up with high air pressures; 2) change in cycling can be glacial sometimes; and 3) manufacturers need a New Product to sell. I haven't done either of these yet, though, mainly just because I got some nice regular wheels last summer.
