Tire pressure for TT
#1
Senior Member
Thread Starter
Join Date: Apr 2005
Location: Victoria
Posts: 1,372
Bikes: 05 Norco CRR Team Carbon Dura Ace, 06 Cervelo P2C TT Dura Ace, 88 Olmo Steelie w. Campy Mirage, Cypress CX w. 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Tire pressure for TT
What do you guys run? I have a Hed/Hed Tri combo, clincher. I've been running 110 but thought perhaps I could go higher. I know at a certain point the tire sort of 'bounces' on the texture of the pavement.
#3
Senior Member
Join Date: Jul 2006
Posts: 1,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
running a 19mm conti olympic tire up front @ 130psi and a rear Tufo elite in the rear @ 160. Front is a little bonuncy but managable. Rear feels perfect aspecially when you want to sprint on it.
#4
Race to train
Join Date: May 2005
Location: suffering on the back
Posts: 3,115
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
it will depend on you tire also, a pro 2 race is 110psi max but tufo go much higher. 110 is fine and you wont need to go higher on a clincher.
#5
Senior Member
Join Date: Jul 2006
Posts: 1,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Just a point that, '110' is just a suggestion. I've ridden 140 in tires that say max 110, the ride sucks on the road @ 140 but nothing exploded/
#6
Outgunned and outclassed
Join Date: Oct 2003
Location: The Springs, CO
Posts: 998
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Above a certain point the rolling resistance actually increases with tire pressure due to the wasted energy in bouncing. Someone has previously posted a nice article with lots of fancy graphs to this effect, but I'm not about to go find it.
#7
Peloton Shelter Dog
Live on the edge dude. 160lbs.
#8
Little Pony
Join Date: May 2007
Location: Salem, OR
Posts: 667
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I've run at 150 psi on vredsteins. it'll all depend on type of tire, wheel and their max. you don't want a tire blowing off a rim.
#9
Senior Member
Originally Posted by VosBike
Above a certain point the rolling resistance actually increases with tire pressure due to the wasted energy in bouncing. Someone has previously posted a nice article with lots of fancy graphs to this effect, but I'm not about to go find it.
#10
pan y agua
Join Date: Aug 2005
Location: Jacksonville
Posts: 31,303
Bikes: Willier Zero 7; Merlin Extralight; Calfee Dragonfly tandem, Calfee Adventure tandem; Cervelo P2; Motebecane Ti Fly 29er; Motebecanne Phantom Cross; Schwinn Paramount Track bike
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 1447 Post(s)
Liked 727 Times
in
372 Posts
Tire pressure/ Rolling resitence should be a sticky thread. So we don't have to keep pulling up the data and links that establish the point Asgelle makes.
https://www.velonews.com/tech/report/...es/7508.0.html
https://www.velonews.com/tech/report/...es/7507.0.html
According to the Tech guy at Zipp:
The other issue to consider is that most every tire on the market runs at optimal rolling resistance between 105 and 125psi depending on load and road surface condition. We have seen data from numerous manufacturers and had enlightening talks with others to learn that nylon cased tires like Michelin or Continental tend to run optimally around 105-115 and cotton or bias cased tires like Vittoria or Vredestein tend to run optimally at 115-125 maybe as high as 130 for Vredestein, but all of them actually will increase in rr at higher pressures due to the tread rubber beginning to fail in shear as it locally deforms to meet the contour of the road imperfections when the casing is too rigid. Think of it in terms of heat input, as the overinflated tire struggles to conform to all the tiny surface imperfections to make the necessary contact patch, a lot of heat is generated. Not only is there higher rr, but faster tire wear as well at higher pressures, not to mention the tires decreasing ability to stay mounted on the rim as pressure increases. In an ideal world tire manufacturers would list a recommended pressure and not just a MAX pressure (the max pressure is simply a predetermined percentage of the bursting pressure of a given tire as set out by industry standards and has nothing to do with the pressure you should actually run) but they are between the rock and hard place as consumers continually push for higher and higher pressures feeling that ‘if some is good, more is better'. Of course none of this even mentions comfort, which we believe to be of increasing importance as more and more data has shown fatigue to be caused by vibration. It may be that by increasing tire pressure by 20-25 psi, you feel faster as your tires are transfering more of the high frequency vibration to your body (you're feeling a higher frequency 'faster' vibrations' so it really does 'feel' faster) but are actually expending more energy to do it, while simultaneously wearing out the tires faster and inducing fatigue.
Looking to pro road teams, most of them are running 100-110 psi in tubulars and 105-120 psi in clinchers, and this has been a bit of a knock against the clinchers from the pros, that they prefer the lower pressures for improved handling, grip and feel, but need additional air to prevent pinch flats. Especially of issue are rainy races, where they may even lower pressure to 95 psi or so for better grip and control in the corners. The only real exception here would be track racing, especially on wood, where the surface is so smooth that very high tire pressures can yield excellent RR results, but still generally reduce grip slightly, but even this is specific as a board track may runn well at 220psi, but a concrete track favors 150-160psi, and some track surfaces are no better than most roads...
https://www.velonews.com/tech/report/...es/7508.0.html
https://www.velonews.com/tech/report/...es/7507.0.html
According to the Tech guy at Zipp:
The other issue to consider is that most every tire on the market runs at optimal rolling resistance between 105 and 125psi depending on load and road surface condition. We have seen data from numerous manufacturers and had enlightening talks with others to learn that nylon cased tires like Michelin or Continental tend to run optimally around 105-115 and cotton or bias cased tires like Vittoria or Vredestein tend to run optimally at 115-125 maybe as high as 130 for Vredestein, but all of them actually will increase in rr at higher pressures due to the tread rubber beginning to fail in shear as it locally deforms to meet the contour of the road imperfections when the casing is too rigid. Think of it in terms of heat input, as the overinflated tire struggles to conform to all the tiny surface imperfections to make the necessary contact patch, a lot of heat is generated. Not only is there higher rr, but faster tire wear as well at higher pressures, not to mention the tires decreasing ability to stay mounted on the rim as pressure increases. In an ideal world tire manufacturers would list a recommended pressure and not just a MAX pressure (the max pressure is simply a predetermined percentage of the bursting pressure of a given tire as set out by industry standards and has nothing to do with the pressure you should actually run) but they are between the rock and hard place as consumers continually push for higher and higher pressures feeling that ‘if some is good, more is better'. Of course none of this even mentions comfort, which we believe to be of increasing importance as more and more data has shown fatigue to be caused by vibration. It may be that by increasing tire pressure by 20-25 psi, you feel faster as your tires are transfering more of the high frequency vibration to your body (you're feeling a higher frequency 'faster' vibrations' so it really does 'feel' faster) but are actually expending more energy to do it, while simultaneously wearing out the tires faster and inducing fatigue.
Looking to pro road teams, most of them are running 100-110 psi in tubulars and 105-120 psi in clinchers, and this has been a bit of a knock against the clinchers from the pros, that they prefer the lower pressures for improved handling, grip and feel, but need additional air to prevent pinch flats. Especially of issue are rainy races, where they may even lower pressure to 95 psi or so for better grip and control in the corners. The only real exception here would be track racing, especially on wood, where the surface is so smooth that very high tire pressures can yield excellent RR results, but still generally reduce grip slightly, but even this is specific as a board track may runn well at 220psi, but a concrete track favors 150-160psi, and some track surfaces are no better than most roads...
Last edited by merlinextraligh; 05-08-07 at 11:13 AM.
#11
Senior Member
Thread Starter
Join Date: Apr 2005
Location: Victoria
Posts: 1,372
Bikes: 05 Norco CRR Team Carbon Dura Ace, 06 Cervelo P2C TT Dura Ace, 88 Olmo Steelie w. Campy Mirage, Cypress CX w. 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Wow, especially thorough, thanks Merlin (and others). I have Deda Tre RS Corsa's, 23's. It seems 110 is not a bad pressure for clinchers, unless it's wet. I think I will continue to run 110.