How 'bout them tiny valve stems...
 

I have a Motobecane with Specialized 27 x 1¼ tires in my scrap heap. I don't know what kind of tube is in there but I've never seen a valve like that before on a car, truck, tractor or bicycle wheel. It's a tiny little thing and I couldn't succeed in getting any air in there at all. Are these still around? Is some adaptor required? I tried air from the compressor and from two different hand pumps but they all seemed to only spray a little wind around the top, without injecting any. I suppose if the wheels are good, I could drill or file a proper sized hole for the typical valve stem.

What's the story?

sounds like you might be talking about a presta valve...
Do the valve stems look like this?http://www.activemobility.co.uk/shop...ertubefull.jpg ??

I'd be surprised if it was anything other than presta valves. You need an adapter, or a pump that fits a presta valve. I have both.

There's a little knurled ring at the top that you loosen (turn counter-clockwise) when filling with air, then you tighten it up again. It won't take air if you don't loosen that ring.

Yep! That's the suspect!

At best, I'm semi-literate when it comes to bikes--and lots of other things.

That explains why I pumped away with no satisfaction. Usually I can look at simple mechanical things and understand them but I felt daunted by that tiny little thing.

presta valve, presta valve, presta valve. I'll remember that. presta valve, presta valve, presta valve, presta valve, presta valve, presta valve, presta valve, presta valve, presta valve, presta valve, presta valve

And for a presta valve, you'll need a pump something like this:

http://www.nashbar.com/profile.cfm?c...eid=&pagename=


BTW - don't drill any holes it it, those valves are fragile enough at best.

And they are the most common valves in most road bicycle tires now. Schraeder valves are usually only found in mtn bike tires or lower-end road bikes. (I think)

Many high end MTBs also come with presta valved tubes. However, one place in MTBing where schraeder valves are still prevalent is in air shocks.

Bromax-You can drill your rims to Schrader valve sized holes,that way you can use either type tube.There are little adapters for using Presta valves in the bigger holes,but you can just build up the Presta valve a bit by wrapping it with strips of duct tape so it doesn't wiggle around in the now enlarged holes.
It is still easier to find a Shrader valved 27" tube at Walmart and sporting goods stores than a Presta valved tube.Luck,Charlie
PS I remember when I 1st saw a Presta valve in a bike store about 36 years ago-I was a bit puzzled-WTF is this????

Oh, I hate those things. Does anyone know how to gauge pressure them other than with a pump with built in gauge? LBS tells me my rims are too narrow to safely enlarge for Shrader valved tubes.

Pick up a few of these, and then you can use a regular gauge.

http://www.mec.ca/Products/product_d...=1140416454886

They make dual-valve gauges.

http://www.neebu.net/~khuon/albums/m...0001.thumb.jpg

Because they sell low end trash. The alloy rims on the Moto are not low end trash. That's why they have Presta valves, and that's why the LBS stocks tubes with Presta valves.

Go with the adapters and the right pump. Leave the Schrader valves to the steel-wheeled import trash.

And tractors. ;)

Presta valve setups allow for narrower rims. All of the mid to high end mtn bike rims i've built up have been presta.
I second the presta to schrader adapter, I always carry two around. I leave them threaded right onto the tube, incase I ever need to stop for air somewhere, presta's are not something everybody has.
I believe they are called "grommets', my LBS carries them for 75 cents i think

Thanks for the tip, khuon. I have the adaptors, can inflate from a standard pump, but the standard gauge just doesn't work.