Bicycle Mechanics - Using a gas station Air pump

Embarrassing to say I've never used one. I have the adapter but have always relied on my floor pump at home and my mini-pump on the road.

I avoid the gas station air pump out of fear that I will blow up my tires in an instant. Is this an unreasonable fear?

I think I should get over it because I cannot get the kind of pressure that I want from the mini pump when I'm out on the road and a floor pump is unavailable to me.

Most gas stations regulate the air pressure between 80 - 100 psig.
Ask the mechanic if you are in doubt.

In the UK you can't use them to inflate tyres. The staff get real upset when you try to as well. They carry signs warning of danger. Personally I can't really see why but there we go.

Most of the newer ones I have seen do not allow pressures above 80 lbs. Lawyers. 80 lbs will get you home, though.

Hmm, I was under the assumption that I'd be getting higher pressures with the gas station pump. At 110 psi that I'm able to attain with my mini-pump, I would be looking to get the tire(s) to max 120-25

Hmm, I was under the assumption that I'd be getting higher pressures with the gas station pump. At 110 psi that I'm able to attain with my mini-pump, I would be looking to get the tire(s) to max 120-25

jqnj and powers2b are correct; 100 psi if you're lucky but more likely 80 (when's the last time you saw a car tire that needed >80 psi?).

The real downside of gas station compressors is you can get oil or water in your air (and therefore your tubes) if the station's compressor needs service or lacks an in-line filter.

As jqnj said, it will get you home but you will want your own floor pump for everyday use; clean air and the pressure you want.

I thought that cars used ~30psi?

I avoid the gas station air pump out of fear that I will blow up my tires in an instant. Is this an unreasonable fear?

:eek: I had a friend use what he was told was a safe air hose. The bang could be heard for blocks. I look over and he is flat on his back. I don’t think he could hear for about 10 minutes and to this day says his hearing is not what it was before the big bang.

Of course the tube was gone and it also ripped the tire apart :eek:

I've got a nice commercial air compressor in my garage left over from my days as a contractor. I keep the hose pressurized all the time to around 95 psi, the same pressure, coincidentally, that my I run my 700c x 32's. With the presta to shrader adapter I keep handy, all I have to do to is hook it up, let the pressure in the hose equalize with the pressure in the tire, and I've got almost instant 95 psi in my tires. When I inflate fat mtb tires, I've got to be a little more careful of course. As for a gas station pump, I agree that they're most likely kept around 90 psi, which is close to normal operating pressure for most air compressor applications. But since you don't know for sure what the pressure is, be careful, and be aware that with lower pressure tires, especially, the danger is that air compressors inflate with such a high volume of air, very quickly, that you could grossly overinflate a bicycle tire within a few seconds.

I thought that cars used ~30psi?
Yep, which is probably why gas stations regulate it around 80-100. If nothing else, the gas station will get you home or inflate most of it so you don't have to pump as much on the mini.

forgive (or yell at) me if i'm wrong, but the "explosion" risk with a gas station pump isn't so much the pressure limitation as it is that the compressor is designed to put out air at that pressure with a flow rate such that car tires (large volume) are inflated reasonably quickly, such that smaller bike tires might overinflate and explode before whatever pressure regulator on the compressor kicks in. either that or I think i read somewhere that some of them usually have a high pressure leak that can be troublesome for small tires.

forgive (or yell at) me if i'm wrong, but the "explosion" risk with a gas station pump isn't so much the pressure limitation as it is that the compressor is designed to put out air at that pressure with a flow rate such that car tires (large volume) are inflated reasonably quickly, such that smaller bike tires might overinflate and explode before whatever pressure regulator on the compressor kicks in. either that or I think i read somewhere that some of them usually have a high pressure leak that can be troublesome for small tires.

You're right that the danger lies in having too much air volume pumped into a tire, very quickly, resulting in air pressure that's too much for the tire to handle. But the pressure that's in the air hose is the max pressure that's going to go into the tire, so for it to be a problem the pressure in the hose has to be higher than the tire can handle.........The way it works is that there are two pressure gauges, one for the tank, one for the hose. The tank is automatically kept pressurized within a certain range, usually between 100 and 125 psi. When it falls below a certain point, the compressor automatically comes on and re-pressurizes the tank. The desired hose pressure is manually set, and the compressed air supplied by the tank will keep the hose pressurized to the set pressure. The hoses I've seen have a max pressure limit of 100psi, I believe. The pressure in the hose won't exceed the pressure that's been set on the hose regulator, unless something's wrong with the regulator or the pressure gauge.

If you go to a station that services over the road trucks, they probably will have air available at well over 100psi. But, given the volume of truck tires, it would likely be set to fill at a rate higher than for cars. Which is to say that you would blow out/up sooner...

I thought that cars used ~30psi?

Yes but auto mechanic's air powered tools require ~90lbs, and many LT truck tires run up to 80lbs.

Watch out for the good old gas stations that still do service. The car lifts run on air and I've seen some that are regulated at 165-170 psi, BTW a good air line will take this much pressure without failure.