futureofamerica

Let me start this post by stating that I am an idiot.

I left home this morning for my 7.5 mile commute with no frame pump and about 3 miles in, got a flat. Fortunately, I was close to a bus route, so I hoofed it over there and made it to work in a reasonably timely fashion. Thing is, now I'm 7 miles from home with a patch kit, a flat rear tire, no pump, and a presta spare. There's a gas station down the road, but I don't know of any way to inflate my presta spare at that gas station.

Does anyone have a method for inflating a presta tube using a gas station air pump and pocket knife that would save me from calling my mom for a ride and feeling like a total ******bag? I would be forever in your debt.

Thanks,
Bert

Cyclologist

The only way I know of is with a tiny adapter that costs less than a fart at a bike shop.

Bushman

ask the gas station guys for an old piece of rubber fuel line (5/16" inside diameter). cut off about 2" and slide over the presta valve. now the tricky part is to get the airchuck filler to work, you need to somehow press the center of the airchuck down so air comes out, try the tip of your knife. Air will come out inflating the tube , it wont be full, but to limp home on)

Adapt, Improvise, Overcome

moxfyre

Hey, tough situation... I had that happen once too

Unfortunately, I don't know of a way to do it but hopefully someone more clever will chime in.

For the future, pick up a little $2 presta adapter, which is basically a nut that couples to the presta valve on the one end and depresses the schrader pump on the other:


You can get 'em at Nashbar (https://www.nashbar.com/profile.cfm?c...All%20Products) or probably any LBS. I keep one in my wedge pack at all times!

moxfyre

Heck, you could use electrical tape to make a fairly airtight coupling between the pump and the presta valve... but the hard part as you say is getting the pin in the pump to depress.

mrbubl

I'm impressed you found a gas station that offered air...

futureofamerica

Wouldn't the stem on my valve depress the nubbin in the pump just as well as the one in a schrader would? Thanks for the suggestions - I'll let you know how it turns out.

Thanks,
Bert

HillRider

I'm equally impressed you could post on an internet forum while 7 miles from home with a disabled bike and have time to wait for replies. How close is the nearest bike shop?

masiman

I hate when that happens! Ya, adapter is the way to go. Make it a standard part of your on the road kit for when you only have shrader pump heads available.

Any place around where you see other bikes? Start looking for someone with a pump. Have your tire changed before you start looking of course.

Good Luck!

futureofamerica

I was close to a bus line that goes to work when I blew my tire so I made it in, fortunately. Actually, it turns out someone else here where I work does have a presta pump, so I should be set... he blew 2 tires on the way in this morning, though, so I have to share my patch kit.

I think maybe this is a dangerous day out on the roads in St. Louis...

Bushman

yes, you need to cut the fuel line tubing just enough so that both the airchuck valve and the presta valve depress at the same time, sometimes its easier to insert a knife tip BETWEEN them so they dont always slip off eachother. Its real fiddly, not gonna lie to you, its actually a real PITA, but hey sometimes you just need to try anyhting.

good luck!

Bushman

and an easy way to store them ON the bike is to put a long allen bolt thru one of the rack mount holes on the chainstay, and thread the adapter onto it. (i find that peopel steal the adapters otherwise if you leave them on the wheels....)

bkaapcke

A better solution is to drill out your rims and put in schrader tubes. 11/32 is what you want. Most rims will not be affected. bk

masiman

That is probably a worse solution. The adapter lets you use either presta or schrader heads. I do not know of any presta adapters for schrader valves. If you are out on the trail, I have found it easier to find someone with presta rather than a schrader pump. Ya you could switch their pump valve, most do. But still, the adapter gives you an option.

HillRider

Actually there is such a thing. Bike Tools Etc. sells them and here is one reference:

https://www.biketoolsetc.com/index.cg...tem_id=SI-2220

masiman

Thanks HillRider,

I was thinking when I wrote that someone would come up with one ! I guess that top portion moves to depress the valve on the schrader?

moxfyre

Wow, you must have some very tech-savvy thieves around! A Schrader adapter is about the only part that I WOULDN'T worry about having stolen in DC

Bushman

^ no we just have lots of hipster bike vandals.

Lurch

The last time I attempted to top off a bike tire at a gas station it actually took air out of my tube. After repairing a flat, the frame pump got enough pressure in to get to the station, but the compressor there was set for car tires and maxed out at about 40 psi or so. I turned to the frame pump again and limped on home. I always carry an adapter though.

I_bRAD

The moral of the story is "why carry a patch kit if you don't have a pump?" Easy solution for next time.

urbanknight

In California, all gas stations are required to provide air, at least for customers.

dck

I always carry one threaded onto the end of the quick release skewer that sticks out a little beyond the dead-end nut.

Rosso Corsa

I always have the adapter with me, I just leave it attached to one of the prestas on my wheels.

lrzipris

FWIW, we keep a floor pump in our office for benefit of the commuters. I've fixed flats for people at work, and sometimes folks just need to top a tire up to the pressure they want. As it sounds like you are not the only commuter at work (post #10), pool your money and buy an inexpensive pump to keep at hand.

tarwheel 

I always carry a Presta-Schrader adaptor in my seatbag. It has saved me on at least one ocassion. However, you have to be VERY careful inflating your tires from service station pumps. It is easy to explode a bicycle tube from over-inflation. I've done that as well, and all the guys working at the station were laughing their heads off.