# 80 PSI enough pressure



## dasho (Apr 8, 2002)

I've been riding for over 10 years and always heard that tire pressure should be in the 100-120 range or more. I was told recently by an avid cyclist (that races) that he does training rides on 60-80 PSI at times and it has no (or little) effect on speed. He isn't a big rider (approx 140 lbs). He's an intelligent fellow and has been riding for many years so it made me take notice. 

If it makes little difference, a rec rider like me would be well served to run low pressure as the ride would be more comfortable. What is your opinion?

Thanks in advance.


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## estone2 (Sep 25, 2005)

80's way low. He probably pinch flats fairly regularly. 60... wow!

I'm 150 pounds and I run 90-105... Usually 95-105. Below that is asking for pinch flats.

Lower PSI actually allows the tire to conform to the road surface better, thereby resulting in a lower rolling resistance - given that you're still at a reasonable pressure.


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## threesportsinone (Mar 27, 2007)

What size tires? how much do you weigh? 

The danger with going too low is pinch flatting, the larger the tire and the lower your weight the less likely you will to pinch flat and the lower you can go.

I'm 160 and run 23's at 110, and 28's at 75.


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## iliveonnitro (Feb 19, 2006)

Watch out in races or any turns over 20mph. Ever hear of rolling a tire? It's not a fun way to crash, and definitely happens in the 60-80psi range.

105+psi for 140lbs.


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## MerlinAma (Oct 11, 2005)

You didn't say what size tire.

I'll assume you ae talking about 700x23 which I guess is the most common size for a road bike.

Several years ago, I dropped my tire pressure from the 120 range to 100 front, 105-110 back. It made a huge difference in the ride quality and didn't slow me down at all. I weigh 165.

80 pounds seems too low. You could try it, but if you start getting pinch flats, you would need to increase the pressure. 

There has been a lot of discussion on tire pressure the last few years. I think everyone ran too much pressure before that.

Here's a chart from Michelin that shows optimum pressure based on weight.

http://www.michelinbicycletire.com/michelinbicycle/index.cfm?event=airpressure.view


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## Ape0r (Oct 2, 2007)

I wouldn't go below whats printed on the sidewall as the minimum pressure, typically 90-100 psi. I know that the Michelin Pro series comes with a chart on the packaging showing what pressure a person of a given weight should be running, but I'm sure its no harm to go a little below that.

Pressure, of course, has a huge impact on ride comfort. However, as others have said... I'd be scared shitless to tear around a corner on 60 psi of 23mm goodness. The tire probably wouldn't let go of the bike, but it would really feel noodly and unstable.


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## Ricko (Jan 22, 2004)

It depends on the tire you're running of course but that's pretty low pressure for your avg road tire. I weigh in at about 215 lbs and run 115-120 psi in my 23c road tires. If I ran as low as 60-80 psi I'd be afraid I'd flatten those skinny tires with my weight...and probably ding a rim on a sharp edge bump as I pinch-flatted.

Bottom line is...depends on a few variables.


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## VaughnA (Jun 3, 2003)

That sounds mighty low. I run on the low side of the recommended but never below the min recommended pressure. I weigh 170 and run 100psi on my Pro2 Michelins. Too low = pinch flats,rolling off the rim and lost speed, Too high=rough ride, flats and lost speed. You'll be faster and have less flats with the correct pressure.


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## My Own Private Idaho (Aug 14, 2007)

I keep my son's tires at about 80 psi, but he only weighs 115. It works very well for him.

Experiment a little bit, and see what you think.


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## Dinosaur (Jan 29, 2004)

80 pounds might be rideable to get you back home, but too low for normal tire pressure.
Look on the sidewall for max and min psi. I bet it says low is 100 psi or close to it. Of course it depends on the tire.


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## tindrum (Mar 5, 2008)

of course, the less you weigh and the wider the tire the less pressure you can get away with. i stick to about 100psi on 23mm and i weigh 165. i couldn't imagine running that size tire at 60 psi... i'm curious as to his reasoning. maybe it works because he is a light guy? i don't know... i certainly wouldn't recommend it.


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## Slim Again Soon (Oct 25, 2005)

*I run 28s in the 85-90 range...*

... and I'm no lightweight.

I recommend it -- you will feel a big difference.


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## tindrum (Mar 5, 2008)

but 28's aren't your average road bike tire.... i can only assume the OP was talking about 23's?


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## Guest (Jun 5, 2008)

I run front tires in the 90 to 95 range.

Rears I run the 100 - 110 range.

These numbers are only as good as the guage on my floor pump.


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## dasho (Apr 8, 2002)

*I'm referring to 700 x 23 tires*

Thanks


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## Kerry Irons (Feb 25, 2002)

*Minimum pressure?*



Ape0r said:


> I wouldn't go below whats printed on the sidewall as the minimum pressure, typically 90-100 psi.


Where do you find this 90-100 psi minimum pressure? I've seen pressure ranges occasionally, but most often only the max. Conti puts no such number on the GP 4000. The standard recommendation is to run your tires at 90-100, and if you get pinch flats, then get wider tires.


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## Cory (Jan 29, 2004)

Kerry Irons said:


> The standard recommendation is to run your tires at 90-100, and if you get pinch flats, then get wider tires.


Works for me.Somebody told me this 25 years or so ago, when I was a fairly new rider running 115-120psi in 27X1 tires (this was before 700c came to the US). I went to 1-1/4 tires at 90, and it was an immediate improvement. 
FWIW, I weigh 240, and my riding is split between two bikes, one with 700x35s at about 75 psi and the other with 27mm Ruffy Tuffys at 95. No pinch flats ever.


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## Slim Again Soon (Oct 25, 2005)

*And get off the 23s...*

... bump the tires up to 25s, at least. You won't regret it.


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## gobike1 (May 12, 2008)

Um so, I have Michelin Pro1 tires and I think they are rated for 75- 80 psi tops. Last week someone pumped them up to about 120 psi. They rode ok and still feel a bit sodt which I imagine is a trait of the tire. SO I'm about 200 lbs. Are these things gonna hold or blow 
out on me a t that high a psi and being overinflated past whats recommended? They are 700x25c. And if thats too much should I be getting a different tire? I have to admit for me these tires feel a little better over inflated.


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## Dinosaur (Jan 29, 2004)

*Min psi*



Kerry Irons said:


> Where do you find this 90-100 psi minimum pressure? I've seen pressure ranges occasionally, but most often only the max. Conti puts no such number on the GP 4000. The standard recommendation is to run your tires at 90-100, and if you get pinch flats, then get wider tires.


Lot's of manufacturers list a minimum psi on the sidewall. I just bought some Specialized (23) tires . They have a minimum recommended psi of 120 and a maximum of 130. My old Michelin Krylion carbons (25's) had a min recommended psi of 80 and a max recommended of 103. I think the old Conti tires used to list a minimum recommended psi. I stopped using them since they stopped making the Ultra 2000.


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## ZoSoSwiM (Mar 7, 2008)

I run as high as possible in both wheels.. 125psi currently. I usually end up putting 130 in though so when I pull off my pump i am at the recommended pressure.


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## goldsbar (Apr 24, 2002)

Unless you're riding on a track, riding at maximum pressure is the best way to get poor performance AND bone rattling comfort. I love it when my wrists feel like they're going to break on every expansion crack.

To the OP, I'm happy that you posted this questions. It shows some enlightenment. Good ideas about lower tire pressures are finally getting out there. 60psi seems really low - pinch flat city. 80psi might work. I certainly wouldn't be concerned about the tires coming off like others have suggested. 80psi is still a lot of pressure.


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## CoLiKe20 (Jan 30, 2006)

I weigh 105 and my bike is 16lbs. I run 80 psi for years on my 700x23. No pinch flat. The only flats are from thorns. It even feels smoother on tubulars on carbon rim.


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## PdxMark (Feb 3, 2004)

*Sheldon Brown (RIP)*

Rolling Resistance

"Rolling resistance" is the mechanical friction generated as the tire rolls. As a segment of the tire tread rolls into contact with the road, it deforms from its normal curved shape into a flat shape against the road, then back to the curve as the tire rolls onward. The deformation of the rubber in this process is what causes the friction.

There are two ways to reduce this friction, each subject to trade-offs:

* The thinner and softer the rubber/fabric of the tire are, the more flexible they become.

The trade-off with this is that the thinner the tire gets, the more fragile it is, and the sooner it will wear out.
* The higher the air pressure, the less the tire will deflect.

The trade-off with this is that if you pump the tire up too hard, you lose the benefits of pneumatic tires: the ride becomes excessively harsh, and traction will be reduced. In addition, extremely high pressures require a stronger (heavier) fabric and stronger (heavier) rim flanges.

Rolling resistance does decrease theoretically with any increase in pressure, but with modern, high-quality tires the rolling resistance at correct inflation pressure is already so low that the infinitesimal reductions gained are more than outweighed by the trade-offs. 



Width and Pressure

Tire width and pressure are inextricably linked. It is a serious mistake to consider one independently of the other. Generally, wider tires call for lower pressures, narrower tires call for higher pressures.

The part of the tire that is actually touching the ground at any moment is called the "contact patch." Generally, the area of the contact patch will be directly proportional to the weight load on the tire, and inversely proportional to the inflation pressure. For instance, if the rear tire of a bike is supporting a load of 100 lbs, and the tire is inflated to 100 PSI (pounds per square inch) the contact area of the tire will be roughly one square inch. If the pressure is reduced to 50 PSI, the tire will squish out until the contact patch has become 2 square inches (or until the rim bottoms out against the tire.)

A common debate among cyclists centers on the issue of whether a wider tire has more or less rolling resistance at the same pressure. The constant pressure is proposed because it appears more scientific to eliminate this as a variable, but this is not realistic in practice. The short answer to this question is that, yes, a wider tire of similar construction will have lower rolling resistance than a narrower one at the same pressure. This fact is, however, of no practical value. If you are comparing two tires of similar construction, with the same load, and the same pressure, either the wider tire is overinflated, or the narrower tire is underinflated!

A tire is supposed to deflect a bit under load. This deflection the whole purpose of pneumatic tires. When you sit on your bike, your tires should visibly bulge out at least a bit under your weight. If they don't, they're overinflated.

Underinflation	Correct Inflation	Overinflation

* An underinflated tire will have more rolling resistance.
* An underinflated tire will be prone to pinch flats.
* An underinflated tire will tend to wallow and may even come off the rim during cornering. This is a particular problem with wide tires on narrow rims. 



* A correctly inflated tire will have negligible rolling resistance.
* A correctly inflated tire will not get pinch flats in normal use.
* A correctly inflated tire will absorb minor surface irregularities, improving rider comfort.
* A correctly inflated tire will absorb surface irregularities without bouncing and losing traction. 



* An overinflated tire will have slightly less rolling resistance.
* An overinflated tire is more prone to damage from sharp rocks and similar road hazards.
* An overinflated tire will give a harsh ride on anything but the smoothest pavement.
* An overinflated tire can bounce on surface roughnesses. This can cause dangerous interruptions in traction, particularly if it happens during corner


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## danl1 (Jul 23, 2005)

Just as a data point, I weigh 185, and ride 95-100 front, 100-105 rear. I've had exactly one pinch flat in my life, and that was when I got jammed up and ran headlong into a square curb. Destroyed the rim, too. 

I should be riding 25's, but don't. 

80 seems light, 60 crazy, except maybe on tubbies.


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## mayukawa (Mar 14, 2006)

I weigh about 170lbs right now. I've tried various pressures on my 700x23 tires. I can go as low as 85psi. Any lower than that, I can feel the difference in handling. Haven't really tested it for efficiency, but most times I keep the front at about 90~95psi front and 100psi rear.


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## smokey422 (Feb 22, 2004)

Uncle Al (the mechanic that writes the column on roadbikerider.com) recommends 90psi in 700X23s and says he has never had a problem with pinch flats.


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## mateoway (Oct 14, 2005)

last week I was in a fast pace group ride and I knew I had low pressure at the begining of the ride as the pace picked up around 30mph it felt like I had a flat like my tires were about to come off .at the slower speeds they felt fine.
When I got home and checked my pressure it was around 80 psi.


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## ZoSoSwiM (Mar 7, 2008)

I'm actually looking to maybe upgrade my tires... Right now I can pump my Kenda's to 125... I would like to hit 150-160 though..


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## TurboTurtle (Feb 4, 2004)

ZoSoSwiM said:


> I'm actually looking to maybe upgrade my tires... Right now I can pump my Kenda's to 125... I would like to hit 150-160 though..


Why??? Wood track? - TF


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## ZoSoSwiM (Mar 7, 2008)

I want less rolling resistance. I doubt I'll ever pump my tires up that much but I would like a little more than 125..


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## bauerb (Jan 18, 2006)

80 PSI ? maybe on a beach cruiser or hybrid. my wife's jogging stroller runs 80 PSI. my racing tires are rated to 145 PSI. I like to run 115-120. 
for what its worth. my last MTB race was few weeks ago. I ran 50PSI in my tubeless tires, i talked to a bunch of guys running PSI in the 30's. they were nuts. the increased rolling resitance was in no way justified by the extra traction produced by increased surface area.


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## C-40 (Feb 4, 2004)

*worthless..*



ZoSoSwiM said:


> I'm actually looking to maybe upgrade my tires... Right now I can pump my Kenda's to 125... I would like to hit 150-160 though..


There are tests that have proven that too much pressure increases rolling resistance because the average road surface is rough enough that the tires loses contact with the road. The feeling of speed you get with an overinflated tire is an illusion. The other problem is a lack of traction. If you rode down the winding mountain descents that I do (at 35-45mph), you'd find yourself sprawled out on the road frequently.


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## goldsbar (Apr 24, 2002)

bauerb said:


> 80 PSI ? maybe on a beach cruiser or hybrid. my wife's jogging stroller runs 80 PSI. my racing tires are rated to 145 PSI. I like to run 115-120.
> for what its worth. my last MTB race was few weeks ago. I ran 50PSI in my tubeless tires, i talked to a bunch of guys running PSI in the 30's. they were nuts. the increased rolling resitance was in no way justified by the extra traction produced by increased surface area.


If you really believe that, why did you buy tubeless tires? The entire purpose of tubeless tires is to allow you to run low pressure. You don't need to worry about pinch flatting at 50psi unless your a true clydesdale. There's a reason for 30psi. Your rear tire won't skip on every little root and rock. It really allows you to put power down much more effectively. I have no idea where you ride, but if it's the least bit technical, 50psi is not more efficient.


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## ZoSoSwiM (Mar 7, 2008)

I can see the whole bouncing off the road thing as a problem. I don't feel like finding my limits because of high pressure.. I wouldn't mind a few extra pounds of air though.


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## TurboTurtle (Feb 4, 2004)

ZoSoSwiM said:


> I can see the whole bouncing off the road thing as a problem. I don't feel like finding my limits because of high pressure.. I wouldn't mind a few extra pounds of air though.


125 is SLOWER (higher resistance) than 110. - TF


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## funknuggets (Feb 4, 2004)

I remember back when the roadbikerider email went out monthly and Ed and ... Ned? did a study on this exact subject. They put riders of different bikes and had them coast downhill the same course over a day, measuring the results at differing tire pressures. I was really interested because many of the guys I roll with have the tendency to pump their tires WAYYYY up, and as a result, it is not uncommon to have a blowout in the parking lot previous to our jaunts.

Anyway... in this study Ed and whomever actually found that ... number one... higher is NOT faster. 95 pounds ended up being just AS fast as the higher pressures. Any speed gains due to "less rolling resistance" or decreased tire deformity in the roads basically peaked at around 95lbs and did not provide any statistically significant gains in speed. In fact, it caused the bike to become more UNSTABLE as it decreased the surface area in contact with the road, as well as decreased the tire's ability to hold the road, or bend to the road surface as the bike cornered. So, in short the only thing you gained by adding more psi, is more instability and a rougher ride. Not to mention the increased stress on your rims.

Therefore I think they came up with the numbers of 90-100 as ideal.


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## EBbiker (Sep 5, 2007)

Low pressure is all the rage in mountain biking. I know many people who run mid 20s on tubeless tires or tubeless conversions. I've heard about some pros running under 20. Everyone says the lower pressure decreases rolling resistance. But mountain biking and road biking are two different animals. Notubes.com sells a tubeless kit for road tires, but I'm not sure what pressures they recommend.


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## bcaronongan (Aug 9, 2007)

EBbiker said:


> Low pressure is all the rage in mountain biking. I know many people who run mid 20s on tubeless tires or tubeless conversions. I've heard about some pros running under 20. Everyone says the lower pressure decreases rolling resistance. But mountain biking and road biking are two different animals. Notubes.com sells a tubeless kit for road tires, but I'm not sure what pressures they recommend.


i run 25 psi on my race bike and trail bike; better traction.

Hutchinson Fusion 2 road tubeless tires are the only tires that will work with notubes.com; 80-100 psi is the recommendation on pressure.


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## MIN in PDX (Nov 29, 2007)

80 psi is totally kosher on tubulars. No pinch flats.


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## funknuggets (Feb 4, 2004)

*dude...*



EBbiker said:


> Low pressure is all the rage in mountain biking. I know many people who run mid 20s on tubeless tires or tubeless conversions. I've heard about some pros running under 20. Everyone says the lower pressure decreases rolling resistance. But mountain biking and road biking are two different animals. Notubes.com sells a tubeless kit for road tires, but I'm not sure what pressures they recommend.


this is rbr...

he is talking about his road bike.


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## funknuggets (Feb 4, 2004)

*agreed...*



MIN in PDX said:


> 80 psi is totally kosher on tubulars. No pinch flats.


but since the OP has entitled himself a "rec rider"... I somehow think we are talking clinchers her.


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## MIN in PDX (Nov 29, 2007)

funknuggets said:


> but since the OP has entitled himself a "rec rider"... I somehow think we are talking clinchers her.


Even on clinchers, it really depends on tire construction of said tire. I once pinch flatted a Veloflex (open tubular construction, super thin) tire 20c wide at 110 psi. But I've ridden nasty Vittoria Zaffiro 25c tires at 55psi over dirt/gravel without any problems due to the tough casing.


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## dasho (Apr 8, 2002)

*Clinchers*

I ride on clinchers only.

OP


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## johnnychimpo (Jul 23, 2007)

CoLiKe20 said:


> I weigh 105 and my bike is 16lbs. I run 80 psi for years on my 700x23. No pinch flat. The only flats are from thorns. It even feels smoother on tubulars on carbon rim.


You sir need double rations!


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## Blue Sugar (Jun 14, 2005)

Talking about what pressures you use on your mtn bike has no relevance here. 80 psi is too low- it will lead to needlessly high rolling resistance, rapid tire wear, and may even cause handling and safety issues. Don't go any lower than the minimum stated on the tire. I run my Conti GP 3000s at 110 in front, 115 in the rear. I weigh about 160.

BTW, don't assume that higher pressures will lead to a harsher ride-I found the opposite to be true. I used to run my tires at low pressure, mainly due to laziness, and have found that pressure in the 110-115 range actually gives a better ride. The tires seem to bounce off bumps and potholes when run at low pressure. I've had ample opportunity to test this theory on rough Connecticut roads.


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## kbiker3111 (Nov 7, 2006)

*Its simple math...*

Tire pressure necessary for rolling resistance, proper grip, and flat protection is entirely dependent on rider weight, since psi directly correlates to the size of the tire contact patch. If you assume .85 inches/tire contact patch (which is pretty standard), you should end up with a distribution as shown. 80 psi for a 140 lb rider is entirely acceptable. 

Now if you're super worried about a tire rolling, like Nitro said, a little more pressure wouldn't hurt.


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## ZoSoSwiM (Mar 7, 2008)

Well.. Yesterday I rode with my normal 125 psi in both tires.. 
Today I dropped to 95/100 and went for a spin. Honestly.. it felt smoother and my average speed was up slightly around this loop. I'm going to try 90/95 tomorrow and see how that feels. I liked the smoothness of the ride a lot. The roads around here suck. I always thought that the decrease in rolling resistance would outweight the harshness... NOPE!


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## howdoesseanroll (Mar 27, 2012)

quick question - based on the michelin chart my weight indicates I need to fill my tires up to 120 PSI every time. 

After a 20 or 30 mile ride I notice that i lose about 10 - 20 lbs of pressure. Is this normal? I weigh 220.


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## maximum15 (Feb 6, 2004)

"125psi currently. I usually end up putting 130 in though so when I pull off my pump i am at the recommended pressure."

This makes no sense to me. How do you let pressure out of your tire removing the pump? Are you depressing the valve accidentally? OR, are you thinking the pssst sound that occurs when you remove the pump is air coming out of the tire? If so, that isn't the case, that sound is from the air coming out of the pump tube. Think about how a presta valve works and you will understand. As far as the tire pressure you are running, that is your choice but I would recommend you try a lower pressure for a while and see how you like it.


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## cxwrench (Nov 9, 2004)

maximum15 said:


> "125psi currently. I usually end up putting 130 in though so when I pull off my pump i am at the recommended pressure."
> 
> This makes no sense to me. How do you let pressure out of your tire removing the pump? Are you depressing the valve accidentally? OR, are you thinking the pssst sound that occurs when you remove the pump is air coming out of the tire? If so, that isn't the case, that sound is from the air coming out of the pump tube. Think about how a presta valve works and you will understand. As far as the tire pressure you are running, that is your choice but I would recommend you try a lower pressure for a while and see how you like it.


not too sure, but i doubt anyone that participated in this thread will see your reply, since it was 4 years ago...but good point anyway


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## Elfstone (Jun 27, 2006)

toomanybikes said:


> I run front tires in the 90 to 95 range.
> 
> Rears I run the 100 - 110 range.
> 
> These numbers are only as good as the guage on my floor pump.


^^^this^^^ I run 25's and I'm 153~157

PAX


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## Peter P. (Dec 30, 2006)

I weigh 135lbs. and run 80-85psi. tops, in my 23mm tires. Contrary to what others have suggested, I don't pinch flat any more frequently than other cyclists I know.

I used to think high pressures say, 100psi., were THE thing but after reading a few articles that piqued my interest, I decided to experiment by lowering the pressure 5psi. per ride until I either began to get pinch flats or the tires felt soft. Once I found that new, lower pressure, I realized I had better grip, particularly on corners, and the tires would stay in contact with the road much better on rough pavement. I feel absolutely no extra rolling resistance or loss in performance.

Higher pressures just make for a jarring, bone rattling ride.


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## Keoki (Feb 13, 2012)

I'm 137lbs and I ride with 110 psi front and back (700 x 23). Do I get flats? Yes, all the time.


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## f3rg (May 11, 2008)

I'm 140-145lbs, and with 23c tires, I run 92 front and 105 rear. Subtract 5psi each for 25c.


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## superg (May 9, 2010)

*Lower pressure = not so good*

Running the tires at a lower than recommended pressure puts more stress on the threads at the sides of the tire. It could cause thread separation leading to tire failure.
You wouldn't catch me going downhill on under inflated tires either, That's plain and simple asking for trouble.


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## Jwiffle (Mar 18, 2005)

Old thread dredged up, but I'll chime in...I run 80 psi on 700x25 tires. No pinch flats. I weigh 155 lbs.


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## cxwrench (Nov 9, 2004)

superg said:


> Running the tires at a lower than recommended pressure puts more stress on the threads at the sides of the tire. It could cause thread separation leading to tire failure.
> You wouldn't catch me going downhill on under inflated tires either, That's plain and simple asking for trouble.


no one is talking about 'underinflated', but 'proper' pressure. if you need to inflate your tires to 'max recommended' pressure, you need bigger tires. plain and simple.


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## cxwrench (Nov 9, 2004)

howdoesseanroll said:


> quick question - based on the michelin chart my weight indicates I need to fill my tires up to 120 PSI every time.
> 
> After a 20 or 30 mile ride I notice that i lose about 10 - 20 lbs of pressure. Is this normal? I weigh 220.


you need bigger tires, for sure.



Keoki said:


> I'm 137lbs and I ride with 110 psi front and back (700 x 23). Do I get flats? Yes, all the time.


pinch flat? that's the only kind of flat that pressure has anything to do with. you should be well below 100psi. and why do you run the same pressure frt & rear when the weight distribution on your bike is more like 60%rr 40%frt?


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## maximum15 (Feb 6, 2004)

I feel like I have been sucked into a Lounge thread dredge. Oh well, someone will still learn something from this thread.


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## Keoki (Feb 13, 2012)

cxwrench said:


> pinch flat? that's the only kind of flat that pressure has anything to do with. you should be well below 100psi. and why do you run the same pressure frt & rear when the weight distribution on your bike is more like 60%rr 40%frt?


1) Yes, all of my flats thus far has been pinch flats. 
2) My saddle position is that the nose of the saddle is facing down enough that I'm not able to ride with one hand, thus majority of my weight rests with my arms (I do a lot of push ups). know this is wrong, but I feel comfortable in this awkward position.
3) Since riders heavier than I (riding 120psi) would be fine, why would this be a problem for a 137lbs rider running the same spec? In theory, I shouldn't have any flats

Edit: I've meant to say "riding with no hands.".


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## cxwrench (Nov 9, 2004)

Keoki said:


> 1) Yes, all of my flats thus far has been pinch flats.
> 2) My saddle position is that the nose of the saddle is facing down enough that I'm not able to ride with one hand, thus majority of my weight rests with my arms (I do a lot of push ups). know this is wrong, but I feel comfortable in this awkward position.
> 3) Since riders heavier than I (riding 120psi) would be fine, why would this be a problem for a 137lbs rider running the same spec? In theory, I shouldn't have any flats
> 
> Edit: I've meant to say "riding with no hands.".


1) sounds like you need to look where you're riding if you're pinch flatting at your weight w/ 120psi
2) why on earth are you in that position?
3) see #1

proper pressure isn't only going to let you roll easier and more comfortably, but you'll have WAAAAYYYYY more cornering traction at under 100psi than at 120. don't you want all the traction you can get? for example, i weigh over 160 and run 85frt/95rr w/ 22mm tubulars on carbon wheels. i've never damaged a rim nor pinch flatted a tire (and yes...you can pinch flat tubulars if you try hard enough)


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## dcgriz (Feb 13, 2011)

Old thread but good subject so here it goes...

With my water bottles full, my 25mm tires carry 259.5 lbs and are inflated to 100f/110r. With 23mm tires, same weight, add 10psi.


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## Keoki (Feb 13, 2012)

cxwrench said:


> 1) sounds like you need to look where you're riding if you're pinch flatting at your weight w/ 120psi
> 2) why on earth are you in that position?
> 3) see #1
> 
> proper pressure isn't only going to let you roll easier and more comfortably, but you'll have WAAAAYYYYY more cornering traction at under 100psi than at 120. don't you want all the traction you can get? for example, i weigh over 160 and run 85frt/95rr w/ 22mm tubulars on carbon wheels. i've never damaged a rim nor pinch flatted a tire (and yes...you can pinch flat tubulars if you try hard enough)


2) In theory this position should give me a 50/50 weight distribution.


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## cxwrench (Nov 9, 2004)

Keoki said:


> 2) In theory this position should give me a 50/50 weight distribution.


you're on a ROAD bike, not a TT bike. while it would be nice, road bikes aren't supposed to have 50/50 weight distribution. level out the saddle and take some weight off your hands.


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## gordy748 (Feb 11, 2007)

My combined weight of rider + bike is 200 lbs, and I ride tubbie 25s. The data chart I have says I should be riding a little over 90 psi per tire, so I have 85 front and 95 rear. I'll drop 5 at the beginning of a hot day, and 10 if it's wet.


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## Guest (May 20, 2012)

My combined weight (rider, bike, clothes etc) is 150lb. I run 95lb front and rear (nominal minimum). I see a few have recommended people who are "too heavy" should go to larger tires, what about people who are "too light" and are already running the minimum on 23s?


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## cxwrench (Nov 9, 2004)

PhotonFreak said:


> My combined weight (rider, bike, clothes etc) is 150lb. I run 95lb front and rear (nominal minimum). I see a few have recommended people who are "too heavy" should go to larger tires, what about people who are "too light" and are already running the minimum on 23s?


if you can ride 95/85 w/o pinch flatting, i'd do it. why run the same pressure frt/rr? you don't have the same amount of weight on the front tire as the rear, why run the same pressure? stick w/ the 23mm tires, no sense going smaller.


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## skepticman (Dec 25, 2005)

I run below the rated minimum on road, cross/touring and 29er tires all the time with no problems, and I weigh 170-175. Running 23mm road rims and tubeless 29er, I have to ignore the manufacturer recommended minimum to get the benefits of lower pressure.


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## Keoki (Feb 13, 2012)

cxwrench said:


> you're on a ROAD bike, not a TT bike. while it would be nice, road bikes aren't supposed to have 50/50 weight distribution. level out the saddle and take some weight off your hands.


Alright fine. I've adjusted my saddle to your recommendation and I will ride in this position tomorrow (70 miles) and let you know how much I've hated it!


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## Salsa_Lover (Jul 6, 2008)

lower your saddle a bit and set it level, try to seat right on your seat bones and curve your back
HTH


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## Silvercall (Sep 21, 2011)

Glad someone revived this thread. I'll be changing my PSI before my next ride...


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## RyanM (Jul 15, 2008)

I am 150lbs and run 700x23 clinchers (conti gp4000s)
I run 80psi front, 90 psi rear and rarely ever get flats and have never felt the tire roll in corners or any problems on fast downhills


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## cxwrench (Nov 9, 2004)

Keoki said:


> Alright fine. I've adjusted my saddle to your recommendation and I will ride in this position tomorrow (70 miles) and let you know how much I've hated it!


making major changes to your position and then riding long miles is never a good idea...but...you'll probably need to give it 2-3wks before you can make a decision about whether the change works for you or not.


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## jct78 (Dec 12, 2011)

i was running my continental GP4000s 25 tires at 120psi rear and 110psi in the front.

yesterday during a technical downhill (jamison cr. road for the norcal), i blew the rear tire off the rim. the bead had separated from the sidewall and my rim got got thrashed when i hit the brakes. I slid out and landed on my ass luckily and only suffered some abrasions on my forearms and upper back.

my buddy tried to tell me that a rider of my weight (220#) should not be running 120 psi in my rear and that my weight with the force during the turn are what caused the tire to blow. i think he's full of it. the tires are rated to 120psi and the rims are fulcrum 5/6. 

the tires had less than 400 miles on them. tire issue or pressure issue? or both??


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## Ventura Roubaix (Oct 10, 2009)

I have weight as much as 235lbs(currently 208), and ran anywhere from 120 to 105 in the rear (normally now about 110 to 115) for 23's, and 90 to 105 in the front, currently 95 in front for 23's about 5lbs less for my 25's. I have never had a pinch flat that I'm aware of. I like the feel of the lower range pressure better (90/95 front, 110/115 rear).


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## cxwrench (Nov 9, 2004)

jct78 said:


> i was running my continental GP4000s 25 tires at 120psi rear and 110psi in the front.
> 
> yesterday during a technical downhill (jamison cr. road for the norcal), i blew the rear tire off the rim. the bead had separated from the sidewall and my rim got got thrashed when i hit the brakes. I slid out and landed on my ass luckily and only suffered some abrasions on my forearms and upper back.
> 
> ...


i'm not surprised that happened. a rider of your size should be on minimum 25mm tires, 28mm if they'll fit. 25mm tires could be inflated much closer to 100psi and 28mm tires around 90 (rear tires). i can't believe that bike shops sell every rider that buys tires 23mm w/ no consideration of rider weight or riding style.


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## Keoki (Feb 13, 2012)

cxwrench said:


> making major changes to your position and then riding long miles is never a good idea...but...you'll probably need to give it 2-3wks before you can make a decision about whether the change works for you or not.





Salsa_Lover said:


> lower your saddle a bit and set it level, try to seat right on your seat bones and curve your back
> HTH


Well I've done only 25 miles today (I thought it was going to rain/shower). I did lower the saddle a bit before I took off (read your comment the night before). The first 8-9 miles felt strange as hell (I can't seem to achieve full power), however towards the end, the tension on the back of my neck was non existent. I usually feel tension there around at the 25 mile mark and pain around at 65 miles. Hmmm..... You guys might be onto something here. I guess I'll have to do some longer rides to truly find out. Oh btw, my saddle is the Sellle SMP Evo.


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## mgringle (May 20, 2011)

cxwrench said:


> i'm not surprised that happened. a rider of your size should be on minimum 25mm tires, 28mm if they'll fit. 25mm tires could be inflated much closer to 100psi and 28mm tires around 90 (rear tires). i can't believe that bike shops sell every rider that buys tires 23mm w/ no consideration of rider weight or riding style.


This is good to know. I'm at 225 and run 25mm tires at 100 f/r and have not had any problems (so far). Conti GP 4000's in an urban environment with pretty rough roads at times.


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## gordy748 (Feb 11, 2007)

jct78 said:


> i was running my continental GP4000s 25 tires at 120psi rear and 110psi in the front.
> 
> yesterday during a technical downhill (jamison cr. road for the norcal), i blew the rear tire off the rim. the bead had separated from the sidewall and my rim got got thrashed when i hit the brakes. I slid out and landed on my ass luckily and only suffered some abrasions on my forearms and upper back.
> 
> ...


Sounds like more to it than tire pressure. What was the road quality? Do you ride heavy or light?

Nonetheless, if you're using 25s, you are a little too much at the front and spot on at the rear. Here's some work that a guy called Frank Berto did. Basically you match your tire load to the tire size you have and voila! there is your optimal psi.

http://www.bikequarterly.com/images/TireDrop.pdf


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## jct78 (Dec 12, 2011)

gordy748 said:


> Sounds like more to it than tire pressure. What was the road quality? Do you ride heavy or light?
> 
> Nonetheless, if you're using 25s, you are a little too much at the front and spot on at the rear. Here's some work that a guy called Frank Berto did. Basically you match your tire load to the tire size you have and voila! there is your optimal psi.


road quality wasn't great at all. lots of patched pavement and small potholes. strava said i was going 19mph. i was definitely riding light since it was my first time descending the road and was wary about my line. i surveyed the area while waiting the 1 hour for my buddy to return with a car and there was nothing there i'd really consider a hazard on that turn. 

i took my bike and tire to the spokesman in downtown Santa Cruz to get their opinion on tire and wheel repair etc. the guy looked at my tire and said that it would most likely not be warranty replacement because it looked as if the tire was ridden while flat. :mad2: sure thing guy...while my ass, back and arm were slowing me down on the pavement.

the wheel is toast, but i can salvage the hub and maybe spokes through a rebuild with Fulcrum.


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