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Tire Pressue(13 posts)

Tire PressueGDR
Mar 7, 2002 5:39 PM
I want to upgrade the tires that came on my bike. When I bought my bike last year the LBS told me to keep 130 pounds of air in the tires, they are conti's wire bead. I wanted to get the michelin Axial Pro but I see the max air pressure is only 110 pounds. Can I ride these at that pressure? If not then what could I ride on, light, low rolling resistance, good traction. I am not going to race but ride about 75 miles a week and will do a couple of centuries a week. I weigh 190 pounds. Thanks.
re: Tire PressueDINOSAUR
Mar 7, 2002 6:10 PM
I've been running 120psi in my Michelin Hi Lite Prestiges (folding). 130psi might be pushing it even for the Conti's (which model?). Over inflation is the main cause of premature tire wear...

Also there are a lot of variables in tire pressure.
http://www.sheldonbrown.com/tyres.html
re: Tire Pressueweiwentg
Mar 7, 2002 6:41 PM
from what I've heard (posted a similar qn on rec.bicycles.tech), Michelin rates their max inflation pressures conservatively. you can run 120PSI if you're not too heavy. I did, but I am pretty light. in any case, even at 110 PSI, the rolling resistance on the Michelins (Axial Pro Light, in my case) was pretty darn low.
re: Tire PressueChen2
Mar 7, 2002 6:46 PM
No problem running Axial Pro's at 120. At 190 you are probably an average weight. And heavier riders should use more pressure, not less.
~Al
Well...(WARNING: STATEMENTS OF OPINION FOLLOW)Ahimsa
Mar 7, 2002 6:48 PM
THESE COMMENTS ARE NOT SCIENTIFIC FACT, BUT RATHER MY EXPERIENCE AND BELIEF. I AM IN NO WAY TO BE SEEN AS AN EXPERT. VOID WHERE PROHIBITED BY SELF PERCIEVED EXPERTS.

..I've always viewed tire pressure kinda the same way I view serving suggestions on a frozen food package, it's just a suggestion. You gotta learn to fix it the way you like it based on what works for you.

Manufacturers tire pressure maximums are actually speced a bit low for safety. Not your safety from popping tires, but theirs from law suits and what not. That is the lawyer and engineer approved number of pounds per square that is best based on testing (we hope). It is not the magic number per se.

You can pump up a 110 to 120....maybe even 130, but there isn't much reason to just cause the LBS said so.

Put it this way:

If it's a higher pressure tire, I go maybe 10 or 20 psi up or down depending on the "feel" as I percieve it. If it's a lower pressure tire (like a 26" MTB) I am more flexible depending on size.

Really you need to find a balance between comfort, the spec, and enough gas to keep from damaging the wheel or pinch flating.

Or worse, too much rolling resistance.

Run the spec psi for awhile on yer new tires until you figure out what it feels like too high and too low.

Cheers!

A.
Um, and who said you could have an opinion?Leisure
Mar 8, 2002 1:09 AM
And what in hell are you doing telling this other person to have an opinion also? Worse, that he should formulate it himself? You BASTARD! Oh, I know, "people will learn and be able to handle more difficult problems, be efficient, contribute, and won't depend as much on others or strain the system"! It always starts out that way, doesn't it...BUT NOOOO!!! People start THINKING and having their OWN ideas that are DIFFERENT from mine! And then they want to find a direction for themselves and make choices and decisions WHEN THEY'RE SUPPOSED TO BE CONFORMING!!!

[insert dramatic pause and crusty here]

WHAT THE HELL ARE YOU DOING TO ME!!!

I can't handle this, I'm spent. I've done all that I can and just can't take it anymore. You're post has hurt my feelings and I now need to withdraw for a while to regain my composure. I sure hope your proud of yourself.
Pressure is your friend...tuffnick
Mar 7, 2002 11:36 PM
You know the best lesson I ever learned to prevent flats (probly the only one actually) is that pressure is your friend especially with tires such as the Axial Pros. I always keep mine above 110 and more in the 140 range. So far I have had very luck doing this compared to before where I probably let it slip down from 110 to 80-90 and then got flats. It is true however you are beginning to push the limits of what the bead can handle... but I can guarantee you unless you are very unlucky the chances of you ever blowing a bead at 110 are a billion to one... add 20 lbs... or approx 20% your still at 200 million to one... I can live with those odds. And for the record very little mathmatical thought went into those calculations :)

-Nick
www.podiumbound.ca (www.podiumbound.ca/test/ for sneak peak)
re: Tire Pressuenetso
Mar 8, 2002 4:18 AM
I have been using Michelin Axial Pros at 120 psi for over 1 year. No problems really. Had one flat when I failed to check the pressure which was about 80 psi. I weigh 204#
Are there two different Michelin Axial Pros?ET
Mar 8, 2002 6:18 AM
I recall a discussion a while back where we realized that the max psi appearing on MAPs is not always the same. Some have 110, some 115 (or was it 120?). Why would they state two different psi's on the same tire?
Are there two different Michelin Axial Pros?weiwentg
Mar 8, 2002 7:23 AM
the sidewall on mine (Ax. Pro lights, 20mm) says that the recommended pressuer is 80-110PSI. I didn't see a max PSI rating.
Are there two different Michelin Axial Pros?LLSmith
Mar 8, 2002 7:24 AM
I think the older ones are 110. All the new ones seem to be 115. At one time I had a 110 on the rear and a 115 on the front.
re: Tire PressueJs Haiku Shop
Mar 8, 2002 6:27 AM
don't we lose few pounds
pressure when removing pump
from presta valve head?

i've always used more
than recommended pressure
partly due to weight

from 190 up
less pressure more contact patch
and squishy rear tire

typically pressure
runs at 120 or more
quick wear, but good ride
re: Tire Pressuecurlybike
Mar 9, 2002 4:38 PM
Ther is no reason to lose air when removing pump from a presta. You will hear the air in the pump hose escaping but that is it. If you depress the presta stem you will lose air, but you are not going to do that, that is an order.