what width tyres are best for racing
- Thread starter catch
- Start date
catch said:
23 bro.
The skinny tires will not result in any less rolling resistance unless you are riding on a surface that is extremely smooth such a a good track. In fact they will slow you down on a typical road surface. It has to do with how a tire molds to the road surface at the a level that you can't see with the naked eye. Part of it has to do with friction and heat at the contact patch on a typical surface...as the tire molds to the surface.
In short the skinny small high pressure contact patch of a tires less than 23mm will increase contact resistance and it will also result in more bouncing force coming back to you which will fatigue you more as well.
Also high tire pressure will also slow you down on a typical surface ....if you are 170 pounds and under run your tires at 110psi..gee don't know how many "bars' that is. If you are over 170 try 115 and don't go to 120 unless you are over 190.
I don't know that I agree with you and would love to see where you got those statistics from. Unless I see some scientific studies I won't believe that a 18c tire pumped up high is going to give more rollong resistance than a 23c tire pumped lower. I am really not interested to get into a pissing match on this point but if you have a scientific article that you can link to I would love to read it.
Either way I don't think that matters to you. If you are worried about the difference in rolling resistance between a 18c and 23c tire you had better be an Ivan Basso or Lance Armstrong and then you would be racing tubulars. There are plenty of other things you can do to increase such as more training, etc. In my opinion it comes down to feel. If you are doing a crit you need to make sure that you are extremely comfortable on the tires that you ride. Cornering is extremely important and you need to be able to throw you bike into that corner hard and tight and not be worried about your wheels going out from under you. I have known many people that would not ride a crit in skinny tires like 18c. I would say to spend the money on a quality pair of tires that have the hard tread in the center and nice sticky stuff on the outside eadge for cornering.
Have fun riding and racing
Either way I don't think that matters to you. If you are worried about the difference in rolling resistance between a 18c and 23c tire you had better be an Ivan Basso or Lance Armstrong and then you would be racing tubulars. There are plenty of other things you can do to increase such as more training, etc. In my opinion it comes down to feel. If you are doing a crit you need to make sure that you are extremely comfortable on the tires that you ride. Cornering is extremely important and you need to be able to throw you bike into that corner hard and tight and not be worried about your wheels going out from under you. I have known many people that would not ride a crit in skinny tires like 18c. I would say to spend the money on a quality pair of tires that have the hard tread in the center and nice sticky stuff on the outside eadge for cornering.
Have fun riding and racing
Here are some comments from Lennard Zinn from Velo News in the tech Q&A:
"Dear Lennard,
I'm a light rider who has always used high-pressure 20mm wide clinchers for training due to their low rotating mass and rolling resistance, However, I'm finding that it is becoming increasingly difficult to find anything but 23mm tires. A local bike shop salesman told me that this is due to the current thinking that a 23mm profile and lower pressures (I usually run 140psi) actually result in lower rolling resistance. I've heard similar comments before, possibly even in your column. Is this true?
It seems counter-intuitive; I would think that with a given tire construction and pressure, a wider cross-section would simply mean a wider contact patch, which should determine rolling resistance. Similarly, I would think that with a given tire construction and size, a lower pressure would mean a larger contact patch, and, therefore, increased rolling resistance. Extrapolating the "wider and softer is better" logic, we should be seeing Lance in the Tour riding balloon tires pumped up to 20psi. Am I missing something or is this a fashion trend?
Langley
Dear Langley,
It entirely depends on the road surface. If it is chip sealed and you ride with a 19mm tire at 140psi, there is no question that you will have higher rolling resistance than with a 23mm pumped to 90psi (assuming that both are high quality high-thread-count tires). Every time you deflect the bike and rider up and back, it costs you energy, as opposed to absorbing the gravel hunks into your tire. This is the same reason that suspension makes a mountain bike, car or motorcycle faster on rough terrain. If you are riding on a smooth track, by all means use a 19mm tire and pump it up to super-high pressure.
http://www.velonews.com/tech/report/articles/5537.0.html
here's some stuff on tyre pressure (high pressure vs low pressure is linked to the "20mm vs 23mm tyre" discussion, because 20s are sipposed to be run at higher pressures):
"Dear Lennard,
I've been reading some of Zipp's comments on tire pressure and rolling resistance attached below. When you really sit down and talk to them about tire pressure they're recommending pressures of 100-120psi (sometimes less) depending on the tire, casing, and environment. I am including comments from Josh at Zipp on this topic. One thing I quickly noticed was the absence of weight in his recommendations. A larger rider running 120 psi compared to a lighter individual (say 30 pounds difference) would exhibit a larger contact patch (resistance or traction however you look at it) due to weight so I'm really not jiving on his basic psi recommendations.
Leaving road conditions out (rain, etc.) what are your thoughts on tire pressure? The common theme of tubulars is the advantage of both weight and tire pressure. The ability to run pressures of 180-200 psi. I know for myself I feel faster (have never tried to test this with rollouts or anything) when running pressures of 140-160 psi (clincher) and 180-200 psi (tubular). I've ridden a number of tires and prefer the ride of higher psi tires such as Vittorias, Vredestein and Tufos.
Do you know of any numbers or tests that prove these thoughts on tire pressure? I've had a number of lengthy conversations with Biomechanists interms of rolling resistance (friction) and don't know how a general recommendation on lower pressures can be faster especially not taking weight into account. It goes against everything I've read about rolling friction. It's pretty easy to point out that the average pro in the peloton only weighs about 150 lbs., so of course it's common sense that they wouldn't need to run similar pressures as you or I, but 100-120 psi seems a bit low when you're talking tire pressure for the most efficient rolling resistances.
I've also been reading your blurbs about tubulars, Tufo and their clincher tubulars. Taking Zipp's tire pressure recommendations in mind where do you stand in regards to Tufo and their clincher tubies and other high pressure tires?
Tom
Dear Tom,
I agree with Josh, and yes, there are lots of test numbers to back it up. It is the same reason a suspension bike (or car) is faster over rough ground - less mass must be accelerated when bumps are encountered, thus saving energy and reducing momentum loss. Every little bump that gets absorbed into your tire (another reason that supple, handmade casings roll faster than stiffer, low-thread-count casings) is a bump that does not lift the entire weight of you and the bike.
You feel fast on a rock-hard tire for a similar reason that people like the feel of stiff brakes (V-brakes with the levers set on low leverage). The brake feels good and stiff because you are doing more of the work. If you increase the leverage, the brake feels spongy, because the extra mechanical advantage allows a modest pull to squish the pads.
When you ride a tire at 170psi, the bike feels really lively and fast. That is because you are being bounced all over the place by the surface roughness of the road. However, every time you are bounced, energy you applied to the pedals to get you up to speed is lost. Also, you have less control of the bike, so it feels like it is going faster, even though it isn't. Ever notice how driving down the highway at 75mph in an old Jeep feels crazy fast, and you can cruise smoothly along at 100mph in a nice Saab or BMW and feel like you are going maybe 60mph unless you are looking at stationary objects passing by?
There is simply no question about it; rolling resistance tests conducted with bicycle tires rolling over surfaces akin to normal road surfaces always indicate the lowest rolling resistance at pressures a lot closer to 100psi than to 170psi! Years ago, for example, I saw results like this at the Continental tire factory. I was told of similar results at a number of other tire factories I have visited.
http://www.velonews.com/tech/report/articles/7508.0.html
"Dear Lennard,
I'm a light rider who has always used high-pressure 20mm wide clinchers for training due to their low rotating mass and rolling resistance, However, I'm finding that it is becoming increasingly difficult to find anything but 23mm tires. A local bike shop salesman told me that this is due to the current thinking that a 23mm profile and lower pressures (I usually run 140psi) actually result in lower rolling resistance. I've heard similar comments before, possibly even in your column. Is this true?
It seems counter-intuitive; I would think that with a given tire construction and pressure, a wider cross-section would simply mean a wider contact patch, which should determine rolling resistance. Similarly, I would think that with a given tire construction and size, a lower pressure would mean a larger contact patch, and, therefore, increased rolling resistance. Extrapolating the "wider and softer is better" logic, we should be seeing Lance in the Tour riding balloon tires pumped up to 20psi. Am I missing something or is this a fashion trend?
Langley
Dear Langley,
It entirely depends on the road surface. If it is chip sealed and you ride with a 19mm tire at 140psi, there is no question that you will have higher rolling resistance than with a 23mm pumped to 90psi (assuming that both are high quality high-thread-count tires). Every time you deflect the bike and rider up and back, it costs you energy, as opposed to absorbing the gravel hunks into your tire. This is the same reason that suspension makes a mountain bike, car or motorcycle faster on rough terrain. If you are riding on a smooth track, by all means use a 19mm tire and pump it up to super-high pressure.
http://www.velonews.com/tech/report/articles/5537.0.html
here's some stuff on tyre pressure (high pressure vs low pressure is linked to the "20mm vs 23mm tyre" discussion, because 20s are sipposed to be run at higher pressures):
"Dear Lennard,
I've been reading some of Zipp's comments on tire pressure and rolling resistance attached below. When you really sit down and talk to them about tire pressure they're recommending pressures of 100-120psi (sometimes less) depending on the tire, casing, and environment. I am including comments from Josh at Zipp on this topic. One thing I quickly noticed was the absence of weight in his recommendations. A larger rider running 120 psi compared to a lighter individual (say 30 pounds difference) would exhibit a larger contact patch (resistance or traction however you look at it) due to weight so I'm really not jiving on his basic psi recommendations.
Leaving road conditions out (rain, etc.) what are your thoughts on tire pressure? The common theme of tubulars is the advantage of both weight and tire pressure. The ability to run pressures of 180-200 psi. I know for myself I feel faster (have never tried to test this with rollouts or anything) when running pressures of 140-160 psi (clincher) and 180-200 psi (tubular). I've ridden a number of tires and prefer the ride of higher psi tires such as Vittorias, Vredestein and Tufos.
Do you know of any numbers or tests that prove these thoughts on tire pressure? I've had a number of lengthy conversations with Biomechanists interms of rolling resistance (friction) and don't know how a general recommendation on lower pressures can be faster especially not taking weight into account. It goes against everything I've read about rolling friction. It's pretty easy to point out that the average pro in the peloton only weighs about 150 lbs., so of course it's common sense that they wouldn't need to run similar pressures as you or I, but 100-120 psi seems a bit low when you're talking tire pressure for the most efficient rolling resistances.
I've also been reading your blurbs about tubulars, Tufo and their clincher tubulars. Taking Zipp's tire pressure recommendations in mind where do you stand in regards to Tufo and their clincher tubies and other high pressure tires?
Tom
Dear Tom,
I agree with Josh, and yes, there are lots of test numbers to back it up. It is the same reason a suspension bike (or car) is faster over rough ground - less mass must be accelerated when bumps are encountered, thus saving energy and reducing momentum loss. Every little bump that gets absorbed into your tire (another reason that supple, handmade casings roll faster than stiffer, low-thread-count casings) is a bump that does not lift the entire weight of you and the bike.
You feel fast on a rock-hard tire for a similar reason that people like the feel of stiff brakes (V-brakes with the levers set on low leverage). The brake feels good and stiff because you are doing more of the work. If you increase the leverage, the brake feels spongy, because the extra mechanical advantage allows a modest pull to squish the pads.
When you ride a tire at 170psi, the bike feels really lively and fast. That is because you are being bounced all over the place by the surface roughness of the road. However, every time you are bounced, energy you applied to the pedals to get you up to speed is lost. Also, you have less control of the bike, so it feels like it is going faster, even though it isn't. Ever notice how driving down the highway at 75mph in an old Jeep feels crazy fast, and you can cruise smoothly along at 100mph in a nice Saab or BMW and feel like you are going maybe 60mph unless you are looking at stationary objects passing by?
There is simply no question about it; rolling resistance tests conducted with bicycle tires rolling over surfaces akin to normal road surfaces always indicate the lowest rolling resistance at pressures a lot closer to 100psi than to 170psi! Years ago, for example, I saw results like this at the Continental tire factory. I was told of similar results at a number of other tire factories I have visited.
http://www.velonews.com/tech/report/articles/7508.0.html
What do the better boys ride around your area? That'll usually tell you right away. I ride 23's at 6-8 bar (95-115 lbs) depending on the conditions. 6 in wet crits, 7 for regular races and 8 for TT's or smooth road RR's. Anymore than that and your comfort level goes down. If I'm comfy, I'm fast.catch said:
Hi Brian,BrianCRPS said:
It's worth looking into tyres if you actually do race. The assumptions you are making are wrong. There's plenty of technical data and info on this out there if you are interested. TiMan is absolutely correct in what he says as are the articles he quotes. 23mm is the optimum tyre width for road racing in the majority of cases. That's why they are so widely used. Narrower tyres are only good for very smooth surfaces like tracks. In fact many pro teams use wider tyres (25mm) both tubular and clincher in races where rough roads are a major factor such as Paris - Roubaix.
Kind Regards Jay
Hi Brian,BrianCRPS said:
It's worth looking into tyres if you actually do race. The assumptions you are making are wrong. There's plenty of technical data and info on this out there if you are interested. TiMan is absolutely correct in what he says as are the articles he quotes. 23mm is the optimum tyre width for road racing in the majority of cases. That's why they are so widely used. Narrower tyres are only good for very smooth surfaces like tracks. In fact many pro teams use wider tyres (25mm) both tubular and clincher in races where rough roads are a major factor such as Paris - Roubaix.
Kind Regards Jay
For road races 23's are the way to go. For time trials/tri's, 19/20's may be a good idea. Going from 22's to 19's can save you almost 15 watts. The 19's do have more rolling resistance, but less aerodynamic drag. I have to run 20's on my TT bike do to clearance issues in the back end(it was designed for 20's).
