a question about tire pressure
#1
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Joined: May 2009
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From: NYC
Bikes: Felt AR1, Cervelo S2
a question about tire pressure
because of my limited experience, i usually inflate the tires to somewhere inbetween the min and max listed on the tire.
my Vittoria Rubino Pro's say Min 100psi, Max 145psi; I inflate them to 130psi.
my Hutchinson's say min 100, max 125. i inflate them to 115.
i'm 175lbs. not a "light" rider. i'm worried that inflating them to the max + pothole = boom.
considering my weight, is this a good rule to go by?
should i go less? could i go more?
my Vittoria Rubino Pro's say Min 100psi, Max 145psi; I inflate them to 130psi.
my Hutchinson's say min 100, max 125. i inflate them to 115.
i'm 175lbs. not a "light" rider. i'm worried that inflating them to the max + pothole = boom.
considering my weight, is this a good rule to go by?
should i go less? could i go more?
#2
You should be fine anywhere in there. I find the ride harsher with higher PSI, I'm about the same weight as you. I run 115 in the rear and about 105 in the front. Less weight on the front. You might experiment some. Try riding at 100 psi. Then jump up to 130 and see if you can feel the difference. Less pressure will allow for more tire "flex" and to a point more traction.
Someone had a web page that talked about determining your actual weight on front then rear tires and had a graph for "optimum" tire "flex". It was lower than I currently ride.
Someone had a web page that talked about determining your actual weight on front then rear tires and had a graph for "optimum" tire "flex". It was lower than I currently ride.
#4
because of my limited experience, i usually inflate the tires to somewhere inbetween the min and max listed on the tire.
my Vittoria Rubino Pro's say Min 100psi, Max 145psi; I inflate them to 130psi.
my Hutchinson's say min 100, max 125. i inflate them to 115.
i'm 175lbs. not a "light" rider. i'm worried that inflating them to the max + pothole = boom.
considering my weight, is this a good rule to go by?
should i go less? could i go more?
my Vittoria Rubino Pro's say Min 100psi, Max 145psi; I inflate them to 130psi.
my Hutchinson's say min 100, max 125. i inflate them to 115.
i'm 175lbs. not a "light" rider. i'm worried that inflating them to the max + pothole = boom.
considering my weight, is this a good rule to go by?
should i go less? could i go more?
#6
Bromptoneer
Joined: Jun 2008
Posts: 2,942
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From: Brooklyn, NY
Bikes: Brompton S2L
because of my limited experience, i usually inflate the tires to somewhere inbetween the min and max listed on the tire.
my Vittoria Rubino Pro's say Min 100psi, Max 145psi; I inflate them to 130psi.
my Hutchinson's say min 100, max 125. i inflate them to 115.
i'm 175lbs. not a "light" rider. i'm worried that inflating them to the max + pothole = boom.
considering my weight, is this a good rule to go by?
should i go less? could i go more?
my Vittoria Rubino Pro's say Min 100psi, Max 145psi; I inflate them to 130psi.
my Hutchinson's say min 100, max 125. i inflate them to 115.
i'm 175lbs. not a "light" rider. i'm worried that inflating them to the max + pothole = boom.
considering my weight, is this a good rule to go by?
should i go less? could i go more?
#7
Senior Member
Joined: Apr 2008
Posts: 2,454
Likes: 2
From Psimet's Tip of the Day thread...
Tip 1 - Inflate your tires before every single ride. Know what the proper inflation pressure should be for your tires. Inflation requirements will vary by rider, bike, tires, conditions, etc.
Below you will find equations that you can use to help determine an appropriate starting point using your weight and the tire's size. Adjust from these baselines to suit needs and conditions.
Proper inflation is the easiet way to avoid flats.
Tire Width=20: Pressure(psi) = (0.33 * Rider Weight in lbs) + 63.33
Tire Width=23: Pressure(psi) = (0.33 * Rider Weight in lbs) + 53.33
Tire Width=25: Pressure(psi) = (0.33 * Rider Weight in lbs) + 43.33
Tire Width=28: Pressure(psi) = (0.33 * Rider Weight in lbs) + 33.33
Tire Width=32: Pressure(psi) = (0.17 * Rider Weight in lbs) + 41.67
Tire Width=37: Pressure(psi) = (0.17 * Rider Weight in lbs) + 26.67
Example: You are 150lbs running 28's
Pressure (psi) = (0.33*150) +33.33 = 82.83psi (rear)
Front Pressure = .9*Rear Pressure = .9*82.83psi = 74.55psi front\
So for 23s run 112psi in the back and 101psi in the front.
Tip 1 - Inflate your tires before every single ride. Know what the proper inflation pressure should be for your tires. Inflation requirements will vary by rider, bike, tires, conditions, etc.
Below you will find equations that you can use to help determine an appropriate starting point using your weight and the tire's size. Adjust from these baselines to suit needs and conditions.
Proper inflation is the easiet way to avoid flats.
Tire Width=20: Pressure(psi) = (0.33 * Rider Weight in lbs) + 63.33
Tire Width=23: Pressure(psi) = (0.33 * Rider Weight in lbs) + 53.33
Tire Width=25: Pressure(psi) = (0.33 * Rider Weight in lbs) + 43.33
Tire Width=28: Pressure(psi) = (0.33 * Rider Weight in lbs) + 33.33
Tire Width=32: Pressure(psi) = (0.17 * Rider Weight in lbs) + 41.67
Tire Width=37: Pressure(psi) = (0.17 * Rider Weight in lbs) + 26.67
Example: You are 150lbs running 28's
Pressure (psi) = (0.33*150) +33.33 = 82.83psi (rear)
Front Pressure = .9*Rear Pressure = .9*82.83psi = 74.55psi front\
So for 23s run 112psi in the back and 101psi in the front.
#8
Thread Starter
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Joined: May 2009
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From: NYC
Bikes: Felt AR1, Cervelo S2
interesting how nonuniform the responses are - some say "no prob!" some say 130 is too much.
these calculations / charts - are they based on the "correct" PSI w/r/t the individual tire max, or is it the universal "correct" PSI based just on rider weight?
these calculations / charts - are they based on the "correct" PSI w/r/t the individual tire max, or is it the universal "correct" PSI based just on rider weight?
#9
Bromptoneer
Joined: Jun 2008
Posts: 2,942
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From: Brooklyn, NY
Bikes: Brompton S2L
You know what they say opinions are like, eh?
#10
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From: Beverly Hills, MI
Bikes: '72 Fuji Finest, '80 Austro-Daimler Inter 10, '06 Fuji Team Issue, '06 Salsa Las Cruces, Nashbar Frame single speed
As Psimet says in in his preface, use the equations as a starting point...
#11
Still can't climb
Joined: Sep 2006
Posts: 23,024
Likes: 6
From: Limey in Taiwan
i also ride vittoria rubino pro and I'm heavier than the OP. I used to pump them up to 115 and i've been experimenting with pressure and i think i've finally found the perfect combo. 104 in the front and 120 in the back. lovely ride.
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coasting, few quotes are worthy of him, and of those, even fewer printable in a family forum......quote 3alarmer
No @coasting, you should stay 100% as you are right now, don't change a thing....quote Heathpack
#14
Here's a link to the article with the graph-based formula: https://www.vintagebicyclepress.com/images/TireDrop.pdf
#17
I eat carbide.


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FWIW - my equations were generated directly from Sheldon Brown's data. I love how there is usually someone looking at my equations and then saying - no....go use Sheldon's page.

If you pay attention almost all of the guides give you about the same numbers. Adjust to suit.
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#18
Thread Starter
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Joined: May 2009
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From: NYC
Bikes: Felt AR1, Cervelo S2
#19
Thread Starter
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Joined: May 2009
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From: NYC
Bikes: Felt AR1, Cervelo S2
Here's a link to the article with the graph-based formula: https://www.vintagebicyclepress.com/images/TireDrop.pdf
note that my tires have a minimum inflation of 100psi. something's gotta be wrong here. maybe its me.
#22
World's slowest cyclist.
Joined: Oct 2007
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From: Londonderry, NH
Bikes: Cannondale CAAD5 and Cannondale Rush
I've never seen anyone have a tire failure as a result of too much pressure (assuming they stay within the sidewall guidelines) but I've seen a ton of flats from not running enough pressure. Don't worry about a tire going BOOM from too much pressure (stay within the sidewall guidelines). But you CAN go softer, and there are benefits to doing so.
#23
I've never seen anyone have a tire failure as a result of too much pressure (assuming they stay within the sidewall guidelines) but I've seen a ton of flats from not running enough pressure. Don't worry about a tire going BOOM from too much pressure (stay within the sidewall guidelines). But you CAN go softer, and there are benefits to doing so.
#25
I don't know, it gives me the same numbers, and it felt very nice when I tried it. That said, I've been putting 85 to 90 in my front since then. It definitely seems weird putting so little air in a 23.




