Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.Robert Gardner
08-11-04, 10:03 PM
I was looking at pumps in a Performance catalog today and noted that many of them are rated in “efficiency”. The “efficiency” numbers run like 45/21 for one floor pump and 390/NA for a Crank Bros. Power Pumps. What in the heck do these numbers mean?