Commuting - Flat...but do I dare use the gas station pump?

I'm tooling along through a foggy, damp 60 degree Boston morning, loving it, thinking "gee, I haven't had a flat in a long time." Sure enough, my rear wheel went slowly down. I pulled over, found the piece of glass that lodged into and sliced the tire (Conti Gatorskin Ultras), replaced the tube, and pumped it up with my hand pump. I'm guessing I got it pumped to 40 psi. Not high performance (Gatorskins are 125 psi max), but enough to get me to work.

There's a filling station about 3 blocks up. I have about 3 miles left to work. The back wheel is a little squishy, but I'm nervous about blowing out the tire. If I flat again, I'll be late for a presentation I'm giving in 45 minutes.

At that point, would you stop at the gas station and top off the tube or ride the semi-inflated tube into work and deal with it later?

I'd top it off....assuming you have a Schraeder-Presta adapter, and only add air for a second or less at a time.

But, I carry CO2 instead of a hand pump, so it would be a non-issue for me.

Does the pump have an integrated pressure guage? If so, I wouldn't hesitate to use it. If not, I would be a bit more cautious, but I would probably use it anyway.

I swear that I have had a few flats that flatted faster the more amount of air I put into them. One morning I flatted and pumped it up to 100PSI and it flatted again in 30 seconds. I then pumped it up to 50PSI and was fine for 20 minutes. Anyhow, I would be careful and top off. However, my road morph is quite the speedy pump.

I'd stop and put some air in. Maybe not max PSI, but some air. You're risking a pinch flat by running it really low.

If there is a big gash in the tire and the tube is peaking through, then don't put more air in.

IIRC, most gas station air pumps don't inflate to 125 psi. I wouldn't hesitate to use it unless I didn't have a presta/shraeder adapter.

I've found that around here, the smaller gas stations only go to 60-80PSI, and the commercial trucking stations go to 90-100PSI. This works out perfectly for me, as the nearest gas station to my work is a Shell commercial cardlock station =D

I actually passed on the gas station. I was too worried about blowing out my tire and being late for work. I don't think this gas station's air hose has a gauge on it.

While pumping up my tire this morning, I was thinking that getting a CO2 inflator might be a good idea, but I've seen others blow tires out with CO2 inflators.

I'll stop by a closer gas station before the ride home and fill 'er up there.

While pumping up my tire this morning, I was thinking that getting a CO2 inflator might be a good idea, but I've seen others blow tires out with CO2 inflators.

I've never heard of that happening...the only way I could conceive of it is by attempting to fill a narrow road tube using one of the larger CO2 cartridges, or "pilot error".

Using the entire contents of a standard small CO2 cartridge on my 700x23 road tires results in a modest under-inflation - around 80-90 psi.

I've seen others blow tires out with CO2 inflators.



i'd say it's probably due to the tire not being seated properly before the CO2 gets applied. they inflate pretty quickly. you might want to get a better pump. i have one which i can get 80psi into and it fits into my saddle bag.

Heres the thing, I spent my entire childhood and beyond pumping up my tires from gas station pumps, using nothing but the heel of my hand as a 'guage'. You give it a shot, give the tire a feel, repeat as necessary.

Back then every station had a pump and it was free, now, if they have something available to the public at all, it's one of them paying things that doesn't seem to put out too much pressure in a hurry, so I imagine they are 'safer' today than they used to be.

I'd stop by the gas station for at least a good shot of air. I don't mind being moderately underinflated when compared to oh-my-gawd-I-hope-I-don't-pinch-flat-on-this-pothole underinflated.

Heres the thing, I spent my entire childhood and beyond pumping up my tires from gas station pumps, using nothing but the heel of my hand as a 'guage'.

Me too. For a while I didn't even have a bicycle tire pump. I just walked my bike over to the 7-11 across the street. :D

So yeah, go for it. If the pump actually puts out high pressure (unlikely), put air in the tire in small bursts.

However, my road morph is quite the speedy pump.

Aren't you glad that someone let you see how good those pumps are? :p
They're not quite so good for mountain bike tires, but it's the only pump I have. They still work pretty decent. :)

Gee...I wonder who that was? :p
I picked one up a day or two later after our tour de flat producing roads of the foothills \ boulder.
I think I may need to shorten that tour name.

... Not high performance (Gatorskins are 125 psi max), but enough to get me to work.

There's a filling station about 3 blocks up. I have about 3 miles left to work. The back wheel is a little squishy, but I'm nervous about blowing out the tire. If I flat again, I'll be late for a presentation I'm giving in 45 minutes.

At that point, would you stop at the gas station and top off the tube or ride the semi-inflated tube into work and deal with it later?

Very few gas station compressors are even capable of producing more than 125psi. Most mechanics work between 80 and 100 psi.

None of the gas station pumps around here put out more than 70 psi.

Heres the thing, I spent my entire childhood and beyond pumping up my tires from gas station pumps, using nothing but the heel of my hand as a 'guage'. You give it a shot, give the tire a feel, repeat as necessary.

Back then every station had a pump and it was free, now, if they have something available to the public at all, it's one of them paying things that doesn't seem to put out too much pressure in a hurry, so I imagine they are 'safer' today than they used to be.

Same here. Back then, the pump island air supply came directly off the station's main compressor in the now extinct full-service garage. Now, you pop in 25 cents and the little electric toy starts up. You're lucky to get enough air to top off a pick-up truck tire at 80psi.

A medium size compressor is one of the best, most useful shop tools I've ever bought. I use it on the bikes all the time.

Heres the thing, I spent my entire childhood and beyond pumping up my tires from gas station pumps, using nothing but the heel of my hand as a 'guage'. You give it a shot, give the tire a feel, repeat as necessary.

Back then every station had a pump and it was free, now, if they have something available to the public at all, it's one of them paying things that doesn't seem to put out too much pressure in a hurry, so I imagine they are 'safer' today than they used to be.

Same here and I'm not all that old (not that I'm saying you're some old geezer). Plus gas station pumps, as mentioned above, generally don't go to very high pressures.

Oh, and CO2 FTW!

I'd top it off....assuming you have a Schraeder-Presta adapter, and only add air for a second or less at a time.

But, I carry CO2 instead of a hand pump, so it would be a non-issue for me.

Speaking of which I just got back from MEC ( http://www.mec.ca ) yesterday and got a Schraeder (how do you pronounce that anyways?) to Presta adaptor just for the emergency fix kit. It costed me $0.75 for the adaptor and I think it's a good investment to have one. It's slightly larger then a pencil (non-mechanical but the old fashion ones) eraser so it'll fit in a small repair kit.


Zero_Enigma

I've used gas station air before, but not in quite awhile.

One thing I learned when I did was to never trust the pressure gauge on the hose.


Speaking of which I just got back from MEC ( http://www.mec.ca ) yesterday and got a Schraeder (how do you pronounce that anyways?) to Presta adaptor just for the emergency fix kit. It costed me $0.75 for the adaptor and I think it's a good investment to have one. It's slightly larger then a pencil (non-mechanical but the old fashion ones) eraser so it'll fit in a small repair kit.


Zero_Enigma
+1
I always have at least one Presta/Shraeder adapter on me, regardless which bike I'm on. It's just part of my tool kit.

None of the gas station pumps around here put out more than 70 psi. Yep, that's been my experience.

Not to mention some of the petro stations have the nerve to charge 50cents for air (cars only) but thier fricking pump head seal is busted and you lose like 20% more air then your pump in. Me peeved!!


Zero_Enigma

So, I stopped by a different filling station on the way home tonight to top off. It was 50 cents, then the compressor wouldn't start, had to find the attendent, who came out and turned it on by hand. No problem pumping up the tire. The guage does only go up to 80 psi and it feels a little squishier than the front (I'm probably not going to top that off tonight because it's supposed to rain buckets tomorrow)

All that took about as long as it took me to fix my flat this morning. The CO2 inflator is sounding better and better.

So, I stopped by a different filling station on the way home tonight to top off. It was 50 cents, then the compressor wouldn't start, had to find the attendent, who came out and turned it on by hand. No problem pumping up the tire. The guage does only go up to 80 psi and it feels a little squishier than the front (I'm probably not going to top that off tonight because it's supposed to rain buckets tomorrow)

All that took about as long as it took me to fix my flat this morning. The CO2 inflator is sounding better and better.

I'm slightly confused or just not reading this right but if the petro station air pump guage only goes up to 80 PSI does that mean the tire will only be inflated to 80 PSI? Or will the pump still pump the tire up to say 100-200 PSI range?


Zero_Enigma

No problem, just do it. Little chance of blowing your tyres out. Just pop it on a give it a quick burst, your tire should be able to handle it easily. Most car tyres have recommended pressure ratings below those of bicycles anyway. I've never had a problem using those things (though I do have a serious problem with them charging for it).

I'm slightly confused or just not reading this right but if the petro station air pump guage only goes up to 80 PSI does that mean the tire will only be inflated to 80 PSI? Or will the pump still pump the tire up to say 100-200 PSI range?


Zero_Enigma

All I know for sure is that the gauge on the air pump goes up to 80 PSI. I'm not sure if it can actually deliver higher pressures. The general concern with gas station pumps is that they are meant to put out much more volume than we need for bike tires. I have heard or read about people blowing out bike tubes with gas station pump -- that was my concern -- but fortunately have had no such personal experience.

I actually find that it is difficult to get enough pressure out of these pumps within the 3 minutes you get for $0.50 to top off my 65-70psi mtb tires. Part of the problem is the abuse these pumps suffer, in that the nozzle is dropped, nicked and consequently it is nearly impossible to seat it properly on the valve stem. I end up releasing pressure trying to seat it before I can add any. That being said, I think you would have to be pretty inattentive to blow out a tube using these pumps. I find that I count to about 20 for a 3-4psi increase, and this is at lower mtb pressures.

Huh. AJU, soundls like you're using some pretty messed up pumps.

I've had station pumps that have pumped up my tires in about 1-2 seconds. Thus my concern about blowing out a tube. According to the posts of others here, it may be that they go from 0 to 80, so to speak, in that time, and no higher.

I just carry a small pump and forget the gas stations. Topeak Mountain Morph is the ish.

Or (grin) use the coins needed to activate the compressor to call for a taxi. There is only one station in the town that has free air and that pump has no gage. I always carry a Presta to Schraeder adapter on my key chain.

I think the old warning about gas station pumps is for kids bikes. If you put 80 to 100 pounds into a baloon tire I can imagine it could get real dangerous real fast. I live in the city and still have not gotten around to geting a pump. I'm always using gas stations. (its free in CT) Max pressure from the pumps with the compressor in them. (push a button it starts) is around 80 lbs. The hoses that are run from a compressor in a garage can be higher especially the ones that ding.