Quote Originally Posted by Jiffer View Post
And he said this explains why he sees tires being filled with pumps at the Tour de France. He could never figure out why they wouldn't just use an air compressor, which would be so much quicker.
Um, an "air compressor" (like you have in your garage) compresses and delivers AIR. They could use pre-filled nitrogen cylinders... but why?

In high-level pro races they just swap wheels... so how long it takes to fix the flat is pretty much irrelevant.

I think the reason they use pumps in that context is control. You know how you fill a great big auto or motorcycle tire from a compressor - go over by a couple-three pounds and then let the air out with the valve in your gauge, right? Leaving the compressor on a skinny road bicycle tire for that extra second or even half-second could be enough to blow it clear off the rim. (BTDT at gas station compressors when I was a kid ) By the time you check and adjust the pressure several times, it's just as quick to pump a road bike tire by hand - with a decent floor pump it only takes 25-30 strokes to go from 0 to 120 (it seems like... I'll count them next time!)