Tuesday, November 4, 2008

Not Im-Presta

I had an interesting bicycling adventure yesterday. Let's call it a tire pressure malfunction, otherwise known as a flat tire. Sadly, this particular flat tire wasn't caused by a stray thumbtack or a pinched tube or any other accidental mishap -- this one was pure operator error. I learned something, though!

It turns out there is a third type of tire valve in addition to the two I'm familiar with. American bikes generally have either Schrader valves, which are exactly the same as valves on car tires, with the little spring-loaded pin in the center, or Presta valves, which are a little more minimalistic, without the spring, and with a screw-lock to keep them closed. I Googled up this photo to show these two types (Presta on the left, Schrader on the right):

I've had bikes with both types, and while I have heard that there are major wars between proponents of each, much like Nikon vs. Canon or Ford vs. Chevy, I've never really cared too much one way or the other.

My commuter bike, which I bought used about a week ago, was feeling a little soft on the rear end. Before riding home from work last night, I decided to add a little air to the rear tire. Conveniently, in the wonderful locked, covered bike parking lot at work (!), there's a bike pump chained to the fence for all to use. I rolled my iron steed over to it, unscrewed the presumably-Presta valve, and BAM! the valve shot off and the tire went totally flat. Ack! It looked like this:

An open chimney from my tire tube to the atmosphere -- not a good way to hold in air. I was stuck. It was 6pm, it was dark, and the valve top was nowhere to be found. I searched and searched with my little LED flashlight my Grandma Jean gave me, but nothing. I'm pretty sure it launched right into orbit.

I guess it wasn't a Presta valve after all. Google now tells me (too late, of course) it's a Dunlop valve, aka Dutch valve...

After a bus ride home and a return this morning, I took my broken bike to the bike repair guy who works at the High Tech Campus (isn't that great?), and he replaced the part and pumped it up in about 3 minutes. He charged me nothing (isn't that amazing?). It now looks like this, and I'm back to biking happily:


Steve said...

Just gotta do things differently over there, dontcha?

Oh, and YES WE DID! :D

Maggie said...

What a disaster! I'm glad you were able to fix your bike and now you can bike to work again! I love all of the commuting pics! Keep it up!

Loes said...

Ha, that is a great story. I thought the "Dutch Valve" was the common one. But seems like it is not so.

MJM said...

Loes - I suppose it's a matter of perspective, eh?