Originally Posted by jsharr
I have always used Zefal frame pumps and been happy with their performance. You do need to know distance from head tube to seat tube to get a secure fit, but most come with a clamp on strap that you can use if the pump is shorter than your top tube. On the downside, they can be a bit noisy and rattle when mounted under the top tube.
I looked on the Zefal site and for some reason they show sizing for the seat tube.