Topeak MTN Rocket CB. This stealthy mini pump weighs a feathery 115 grams and features a locking carbon handle and high volume carbon sheathed barrel for inflating fat MTB tires. Fits both Presta and Schrader valves.
a Cross Country Rider
from OC, CA
Date Reviewed: February 26, 2010
Strengths: Strong barrel, air volume to size ratio
Weaknesses: Simplistic head, plastic internals
I bought this as a backup to my CO2 valve in case something ever goes wrong with it on the trail. I chose this carbon version not for the weight savings but rather for dent protection as some aluminum barreled mini pumps I have had in the past were rendered useless if the barrel dented against a rock during a crash.
They say this comes in at a quarter pound, but feels heftier than that. The main weakness is the head, which is one of those plastic + rubber ring setups. I don't like these because it is difficult to judge if you have the head down far enough on the valve. If you go too far you risk ripping the moving piece of the presta valve off, which is what happened when I tried the pump out a few times before throwing it in my pack. The internals are also plastic, so when pumping you need to be prudent to compromise between using all of the pump travel and pumping air at a reasonable rate. By feel I would not want to tug on the pump too hard after it is extended out all the way.
Resistance also builds up significantly as you approach 30+ psi. I was impressed by how quickly you could get an empty tube to a rollable pressure with such a small pump. It is quick and easy (but requires many pumps) up to a certain point. I didn't measure the pressure at which resistance starts to build heavily, but this pump will get you most of the way there fairly quickly.