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Min PSI(19 posts)

Min PSIPEDDLEFOOT
Aug 7, 2003 4:45 AM
Whats the minimum PSI in a 700x23 tire before risking pinch flats.
Too many variables...biknben
Aug 7, 2003 4:51 AM
Type of tire? Rider Weight? Road conditions?

I've riden a tubular with 40 psi for 10 miles and didn't pinch flat. :^)~
You better pump them up hard tonightMR_GRUMPY
Aug 7, 2003 5:14 AM
cuz' I won't be pointing out rocks or potholes........................(just kidding)
Doug might censor a response like that :-) nmpitt83
Aug 7, 2003 5:20 AM
Unfortunately I will be absent :- ( (nm)PEDDLEFOOT
Aug 7, 2003 5:28 AM
No excuses.......MR_GRUMPY
Aug 7, 2003 5:46 AM
Remember, riding comes first.
100 rear, 95 front. I'm 165 lbs. nmSpunout
Aug 7, 2003 5:23 AM
depends on how you ride, your tires and how heavy you areColnagoFE
Aug 7, 2003 5:30 AM
I'm 195 and use Conti GP3000s usually and run them about 110psi both front and rear and rarely to never get a pinch flat. Some say that you don't need this much pressure, but anything less just feels "squishy" to me.
DittoMR_GRUMPY
Aug 7, 2003 6:17 AM
110 in front 120 in back for me. Someone 150 lbs could ride with 90 front and 100 back.
Squishy feeling tiresBacco
Aug 7, 2003 1:56 PM
I have been running my Conti GP3000s at 115psi and they still feel very squishy to me compared to Michelin Axial Pro or Carbon tires. I weigh 170lbs. Therefore, I wouldn't recommend GP3000s at any tire pressure. I will be switching back to Michelins or trying some other brand in the near future.
Why would you not use the max psi?NatC
Aug 7, 2003 5:36 AM
I pinched a couple of days ago with 110psi when the person I was drafting glided by a golf ball-sized chunk of asphalt without pointing it out. POW!!!
uncle al's advice from roadbikerider.comtarwheel
Aug 7, 2003 5:40 AM
The Case for Lower Tire Pressure

DEAR UNCLE AL: Perhaps you can settle an argument at our bike club. I like riding 20-mm-wide tires
inflated to 120-130 pounds. I feel faster because of what I think is lower rolling resistance. Others argue for
a 23C width at 100-110 psi, saying these tires are more efficient because they absorb pavement
irregularities better. I weigh 175 pounds and ride at an average of 18+ mph on a variety of road surfaces.
So who's right about width and pressure? -- Greg C.

UNCLE AL FIRES BACK: Soften up, Greg!

Most everyone I know runs too much pressure. Welcome to the club. Over many years of testing and
talking to guys who live on their bikes, I'm convinced there is little reason to run more than 95-100 psi --
and there are compelling reasons to run 85-90 psi.

High pressure, say 100-120 psi, guarantees short tire life, poor cornering and lots of punctures. A
rock-solid tire cuts/punctures more easily than it would at a lower pressure. Also, a softer tire can "smear"
-- conform better to objects encountered on the road. Why make the ride even rougher on America's
ever-crumbling road surfaces?

Admittedly, I weigh 210 pounds and ride on really poor road surfaces. These things influence my opinions.
I run 85-90 psi front and 90-95 psi rear on 700x23C clincher tires. I do not have flats! Plus, bumps are
less of an issue, and my bike corners as if on rails on high-speed descents. I get 1,000-1,500 miles out of
a rear tire. When I ran much higher pressure many years ago, I got no more than 500 miles.

So, my advice is never to run smaller than 23C. Use good tubes, air them up before every ride and spend
extra for premium tires -- they'll pay you back in extra mileage and better handling.

One more thing: Don't buy a race-specific tire to train on. If it's advertised to last only 500 miles, they
aren't lying. Shaving grams off of training tires is silly and wasteful, and you won't get the low-weight
advantage when event time comes if you ride the light stuff all the time. Make gram shaving your secret
weapon, if only in your mind, when it counts.

Do as I recommend and I promise fewer flats, happier miles and no noticeable increase in rolling
resistance (the great myth). Plus, you'll waste fewer resources, both financial and natural.

FROM ARNIE L.: As a roadie of 20+ years, but a new reader of RoadBikeRider, I was intrigued (and
skeptical) of your advice to lower tire pressure. I have been riding at 125 psi or more, concerned about
rolling resistance (although the extra 10 pounds around my waist probably matters a whole lot more to my
performance).

Well, I thought I'd try it. I lowered my pressure to 105 psi. What a great difference! I haven't really noticed
any change in performance, but what a difference in the ride! One of my usual rides over badly cracked
roads (usual Pennsylvania stuff) was sooo much more comfortable. It seemed like the road had been
repaved. Thanks for the advice.
uncle al is wrongColnagoFE
Aug 7, 2003 6:00 AM
I've run these kinds of pressures before with Conti GP3000s and the bike just plain feels squirrely. I don't care if pinch flats aren't an issue even (though at those pressure I think they are) I just don't like the feel of squishy tires and I get flats way more often if I don't keep them pumped up.
just offering his "advice" as food for thoughttarwheel
Aug 7, 2003 6:43 AM
I think Al is right that a lot of cyclists put way too much air in their tires, to the point where their tires jump around on rough pavement. I've got a friend who has back problems and has been trying a bunch of different saddles. I asked him how much pressure he put in his tires, and he was using something like 130 lbs. I guarantee lowering his air pressure would help his comfort as much or more than a new saddle.

I've been experimenting with lower pressures this summer. I used to run about 120 lbs and had cut back to around 110. This summer, I've been trying about 100-105 in the rear, 95-100 in the front with Michelin Axial Pros. It does feel a little different, but I wouldn't say squishy. I don't seem to be getting any more or less flats. I noticed a huge difference in comfort (for the better) when I switched from 20 to 23 tires, so much that I've considered trying 25s, but they're hard to find on sale and I'm a tightwad when it comes to tires.
yup...most probably run them way too high (nm)ColnagoFE
Aug 7, 2003 10:04 AM
Thanks for the articleNatC
Aug 7, 2003 6:20 AM
I'll try it, although I usually avoid taking advice from anyone who calls himself Uncle (unless he's my uncle).
Why would one use max psi?Spunout
Aug 7, 2003 6:38 AM
Too hard, tire wear, no clear benefits, no comfort.
Less rolling resistance...NatC
Aug 7, 2003 7:33 AM
is the reason why I've been using 110psi. I've only had a road bike a very short time though. I'm going to try less pressure today and see what I think.
I used to think that...actually still do a bit...biknben
Aug 7, 2003 6:53 AM
I always pumped my tires up to the max stated on the side of the tire. That typically meant 120 psi. I did this so that I wouldn't have to pump them up so often. I didn't realize the benefits of lower pressure. Now I've learned that there is a significant increase in comfort with just a 10 psi reduction.

That being said, I still pump them up to 115-120 but I enjoy the comfort the next day when the pressure has reduced a bit. I'm just lazy and don't want to pump those babies up "every" day.

My Conti's do feel squishy at anything below 105 psi. If I go too long without pumping them up, I'm always looking down thinking I have a flat.