Originally Posted by
Arthur Peabody
FWIW I 'reamed' the head of the pump (it's a cheapie with a non-replaceable head) with the butt end of a Bic pen - I didn't want to use a drill bit - and now it attaches to stems normally. I guess it just needed some pushing out.
This makes me think you are using a frame pump instead of a floor pump.
If so, then I'm imagining that since the frame pump attaches directly to the valve body you are simply rocking the stem back and forth with every stroke of the pump and simply wearing out the stem against the hole in the rim.
And if that is the case, maybe you should consider getting a floor pump. Though if you insist on a frame pump, a while back I saw that they were making hose adapters you could attach to the frame pump. That might give enough relief to the valve stem to not have to endure every bump of your pump stroke.
And personally I'm not opposed to a cheapie floor pump. Mine cost less than 10 dollars at Walmart or Target circa 2008 or '09 when it was bought. Still works fine, though I did replace the hose and chuck a while back.
Also, if it is indeed a floor pump you have, while you say you can't replace the head you probably can replace the chuck (head) and hose together. Most chucks for frame pumps are sold with the hose already attached to the chuck. And they usually easily detach from the pump body with a clamp band or ferrule that unscrews.