Originally Posted by
MEversbergII
1) How much pressure are frame pumps, in general, "good for"? They lack a strong base to push against, so I suspect they might not be able to get the 100-120 pounds my tyres ask for.
2) Are they typically brutal on Presta valves, specifically the stems? Is there a technique to it, or is it a problem with cheap pumps (a concept I am wholly abandoning)?
3) When detaching, do these usually have issues causing leaks? Or is that another technique and or cheap pump thing?
1. How much pressure any hand pump can produce is dependent on the operator. It comes down to the stroke and diameter of the barrel. Longer pumps take less time to fully inflate your tire and skinnier barrels allow you to inflate your tire harder. The laws of physics can't be violated regardless what material the pump is made of or what pressure the manufacturer says it will attain.
2. Damage to Presta valves is usually a technique issue. In general, you don't want to wiggle the valve stem with every stroke. That's one reason why Road Morphs, which have a hose are so highly regarded. Too bad they're so clunky-looking. When I use a pump that doesn't have a hose, I grip the pump and tire with one hand and brace it against a tree or post of some kind.
3. When unclamping the valve stem try holding the tire vertically with the valve on top and press straight down. Wiggling the valve stem is bad.
You didn't ask but the only good thing about mini pumps is they're easy to carry when you're not using it.