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cooperwx 09-05-06 09:32 AM

High pressure tires
 
How do you get enough air in the things? I am running 700x32, 100+psi tires, and I can't seem to get enough air in them with my little frame-mounted pump.

Do I need an air compressor?

rhenning 09-05-06 09:37 AM

Get a good floor pump. Blackburn, Park,Joe Blow, etc. Roger

DanPT 09-05-06 09:41 AM

Cheap pump can't pump properly, I personally use a topeak road morph with gauge. Works great can pump to 120 without too much effort.

Sheldon Brown 09-05-06 09:55 AM


Originally Posted by cooperwx
How do you get enough air in the things? I am running 700x32, 100+psi tires, and I can't seem to get enough air in them with my little frame-mounted pump.

"Little frame-mounted" pumps are intended for emergency use, fixing a flat on the road so you can get home.

For routine inflation you should have a floor pump.

By the way, 100 psi in a 32 mm tire is ridculously high unless you're VERY heavy or riding a tandem.

See: http://sheldonbrown.com/pressure

Sheldon "80 Is Plenty" Brown
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peripatetic 09-05-06 10:15 AM


Originally Posted by Sheldon Brown

Sheldon "80 Is Plenty" Brown
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I think this is my favorite so far, Mr. Brown.

Artmo 09-05-06 06:33 PM


Originally Posted by DanPT
Cheap pump can't pump properly, I personally use a topeak road morph with gauge. Works great can pump to 120 without too much effort.

+1

cooperwx 09-06-06 06:18 AM

Thanks for your reference article, Mr Brown, and thanks for pump recommendations, all.

So I either need to stop worrying about getting to 100psi, or get a better pump. I'm on-road 99% of the time, and on rough gravel for about 200 yards a day. I figure I'm running a wider tire than most commuters. I wanted to be at 100psi because 1) it's the recommendation on the tire 2) I'm worried more about pinch flats than punctures, and 3) I can't stand seeing so much tire in contact with the road.

NoRacer 09-06-06 07:05 AM

I use a frame mounted Hurricane Air Scepter with a max of 110 PSI or sometimes I carry 12 or 16 gram CO2 cartridges and a pump.

At home, I have a Silca Pista floor pump rated at 200 PSI.

Little Darwin 09-06-06 07:16 AM

I can add a vote for the road morph, at least up to the 80-90 PSI I run. But, also agree that for routine inflation a floor pump is better. There are also CO2 inflation systems that I haven't used yet.


Originally Posted by cooperwx
I figure I'm running a wider tire than most commuters. I wanted to be at 100psi because 1) it's the recommendation on the tire 2) I'm worried more about pinch flats than punctures, and 3) I can't stand seeing so much tire in contact with the road.

1) Is it a recommendation, or a maximum? There is a difference...

2) I run wider tires than you (26 X 1.5) and run at 80 psi (below the specified max by 10) and have never had a pinch flat. I weigh 318 and have weighed up to about 340 while riding these tires. I ride a few pretty rough paved roads and gravel rail trails...

3) Don't look. :D

oboeguy 09-06-06 08:08 AM

Joe Blow Pro floor pump. You'll be glad you spent the $$$. Pumping with this thing is effortless and once you figure out how to properly use the SmartHead (does both Schraeder and Presta) you'll want to top off the tires every day like I do. :) Oh and the spring on the SmartHead is strong; watch out with your fingers!

zum 09-06-06 08:39 AM

I have a short fat pump which brings me up to 60 psi quite quickly and easily. Then I have a 400 psi shock pump that I use to raise to 100 psi. I use 26 x 1.25 and 100 psi purely to reduce rolling resistance, the reduction in fatigue is noticeable.

John E 09-06-06 08:52 AM

1 Attachment(s)
Sheldon, I like your article on tire pressure, but having experienced fatigue-related sidewall breakdowns, I now lean toward the upper end of your recommendations. Some tires have both minimum and maximum pressure recommendations, and I try to keep them within range. I also tend to run the rear tire 5-10 PSI harder than the front, to accommodate some of the difference in static load.

As for pumps, I have had very good luck with several different brands and models of floor pumps. For on-the-road repairs, I like a full-size frame-fit pump, viz:
Bianchi & Capo: Zefal HP-X
Schwinn: Mt. Zefal
UO-8: Blackburn FP-1M.

Sheldon Brown 09-06-06 09:29 AM


Originally Posted by cooperwx
Thanks for your reference article, Mr Brown, and thanks for pump recommendations, all.

So I either need to stop worrying about getting to 100psi, or get a better pump. I'm on-road 99% of the time, and on rough gravel for about 200 yards a day. I figure I'm running a wider tire than most commuters. I wanted to be at 100psi because 1) it's the recommendation on the tire 2) I'm worried more about pinch flats than punctures, and 3) I can't stand seeing so much tire in contact with the road.

1) See: http://sheldonbrown.com/pressure for the valuelessness of the "recommendation."

2) 100 psi is way more than needed to prevent pinch flats with a 32 mm tire, unless you're VERY heavy or are a VERY abusive rider.

3) So don't look down! ;-)

The whole purpose of pneumatic tires is to permit the tire to flex as it contacts the surface. If you go to a more reasonable pressure, you'll find the bike will handle MUCH better in the gravel, and it will also give you a more comfortable ride and better traction on the pavement.

Give it a try at 80 psi and you'll see what I mean. Maybe 70 in front, unless you weigh 300 pounds.

Sheldon "Pneumatic" Brown
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moxfyre 09-06-06 10:48 AM


Originally Posted by cooperwx
How do you get enough air in the things? I am running 700x32, 100+psi tires, and I can't seem to get enough air in them with my little frame-mounted pump.

As others have pointed out, a "little frame-mounted pump" probably won't do the job. I have a Blackburn Airstick mini-pump that's supposed to do 120 psi, but I can barely get 50 out of it. What a gip :mad:

On the other hand, there ARE some good quality frame pumps (the long kind, not the mini-pumps) which can do 100+ psi. I got a Zefal frame pump for my girlfriend and it does 100 psi easy, in only about 30-40 strokes of the pump for 28 mm tires.

Cyclepath 09-06-06 03:39 PM


Originally Posted by Sheldon Brown
"Little frame-mounted" pumps are intended for emergency use, fixing a flat on the road so you can get home.

For routine inflation you should have a floor pump.

By the way, 100 psi in a 32 mm tire is ridculously high unless you're VERY heavy or riding a tandem.

See: http://sheldonbrown.com/pressure

Sheldon "80 Is Plenty" Brown
Code:

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|  People are more violently opposed to fur than leather        |
|  Becaue it’s safer to harass rich women than motorcycle gangs  |
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Unless the gang is wearing furs.....

duffer1960 09-06-06 03:56 PM

If you still want 100 psi after recommendations against it, here's my advice.

Get a floor pump with a 'narrow' cylinder, not a 'fat' one. I've used both types inflating my 27 x 1 1/8 tires to 100 psi, and it was nearly impossible with the 'fat' barrel pump. I'm sure I'd have broken the 'fat' one eventually, if i had tried it more than a few times. (It's plastic and came from wally mart). Will bring the skinny one next time.


-Rich

moxfyre 09-06-06 04:03 PM


Originally Posted by duffer1960
If you still want 100 psi after recommendations against it, here's my advice.

Get a floor pump with a 'narrow' cylinder, not a 'fat' one. I've used both types inflating my 27 x 1 1/8 tires to 100 psi, and it was nearly impossible with the 'fat' barrel pump. I'm sure I'd have broken the 'fat' one eventually, if i had tried it more than a few times. (It's plastic and came from wally mart). Will bring the skinny one next time.


-Rich

I think the Walmart part is the problem ;) A pump with a larger-volume barrel will be harder to pump on eachstroke, but will require fewer strokes to reach the desired pressure, all else being equal (e.g. the quality of the seal on the pump!)

sivat 09-06-06 07:12 PM

The problem with the wide pumps is that you may not have enough strength to pump up the tire to the desired psi. If you want to get 100psi in the tire and the pump has a diameter of about an inch, you will need to use 100lbs of force to get the tire to the desired pressure. Not easy to do with a hand held pump. If the diameter is decreased to about .8 inches, you only need 50lbs of force from your arm to get 100lbs in the tire.

moxfyre 09-06-06 07:50 PM


Originally Posted by sivat
The problem with the wide pumps is that you may not have enough strength to pump up the tire to the desired psi. If you want to get 100psi in the tire and the pump has a diameter of about an inch, you will need to use 100lbs of force to get the tire to the desired pressure. Not easy to do with a hand held pump. If the diameter is decreased to about .8 inches, you only need 50lbs of force from your arm to get 100lbs in the tire.

Yep, that's certainly true, the required force increases with the square of the diameter. But a 1 inch diameter barrel will require only 78.54 lbs of force ;-) I've not had a problem with wide-barreled floor pumps, myself.

Frame/mini pumps pretty much always have a narrow barrel, 0.5 inches or less. 0.5 inch diameter means only 19.6 lbs of force to do 100 psi, definitely easy to do with a hand-help pump.

Surferbruce 09-06-06 07:54 PM

on 32's you not gonna gain much past 80 psi.

Cyclepath 09-06-06 08:05 PM

I love my "fat" Zefal Double Shot. Pumps easily on both strokes & tops off a hi pressure tire with a few strokes. 15 years without repair or maintenance except a replaced valve head. (Better than the original, Schrader or Presta at the flick of a switch.) The gauge is mounted at the top of the handle. Don't know if they still make them.

mrkott3r 09-06-06 08:57 PM

silca pista

FIVE ONE SIX 09-07-06 08:47 AM

i would recommend that you get a good floor pump, either a high end Joe Blow or Park Tools pump, for around $60 or so. there's a BIG difference between low end pumps and high end pumps, the main of which you'll notice when you hit around 100PSI or so. you will have to lift your feet off the ground, with a low end pump, to inflate a bicycle tire to 120PSI. that doesn't happen with a high end pump, they pump effortlessly, even to 120PSI or higher...

and honestly, you SHOULD inflate your tires before EVERY ride, you're going to lose some type of tire pressure every day. considering tire pressure is one of the most important things that you need to check before every ride, and you're going to use it before every ride, i would say that the money you spend on a higher end pump is more than worth it...

i'm a roadie, and i don't know how mountian bikers feel about this since they don't have to inflate to 120PSI or so, but that's just my opinion...

moxfyre 09-07-06 09:06 AM


Originally Posted by FIVE ONE SIX
and honestly, you SHOULD inflate your tires before EVERY ride, you're going to lose some type of tire pressure every day. considering tire pressure is one of the most important things that you need to check before every ride, and you're going to use it before every ride, i would say that the money you spend on a higher end pump is more than worth it...

i'm a roadie, and i don't know how mountian bikers feel about this since they don't have to inflate to 120PSI or so, but that's just my opinion...

Hmm... I pump my 28 mm tires on my commuter road bike to about 100 psi, and don't inflate them more than about once a week, tops. And that's only because my front tire has a very... slow... leak. I don't think my back tire would need pumping more than once a month or so :)

FIVE ONE SIX 09-07-06 09:28 PM

well, in my opinion, one of the most important things on a bike that you can control is tire pressure. like i said, i'm a roadie, and if i'm going out for a 40-60 mile ride, the first thing i'm going to check is my tire pressure...

and i should have said check their tires, but most everyone i know just deflates their tires for a second, then inflates them to 120PSI. even if the pressure drops to say 115PSI, 5PSI is 5PSI, and something as small as DOES effect your ride...

but like i said, that's just my opinion, and it may certianly vary from other people opinions...


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