• 02-26-2005
    baking3
    Exceedingly stupid pump question
    Here's the problem, I finally got a floor pump (a Big Red Pump from Nashbar), when pushing my electric pump to its pressure limit finally killed it.

    The new pump has one of those dual, auto-selecting heads. It seems like it's awfully hard to get the head onto the stem (both Presta and Schrader) even when "unlocked". It's also really hard to get it off again (for instance, I ripped a stem off of an older but still-holding-air tube this way).

    Also, I seem to lose a fair amount of pressure when I do get the pump head off (if I pump it to 110 lbs., remove the pump, then put it right back on, the pressure sometimes drops as low as 85 lbs.).

    Am I just doing something astoundingly stupid?

    bak
  • 02-26-2005
    torquecal
    not a stupid question
    Some pump heads are tighter than others and as long as you've got the locking lever positions right they can be confusing.

    First off, some pump heads do break in over time and geat easier. Sounds silly but spitting into the pump head prior to attachment can make things easier for both attaching and pulling it off.

    Second, don't just pull the pump head straight off the valve, twist it (gently!!!) as you pull it off.

    Third, on air loss. At least for presta valves, the vast majority of that whooshing sound you hear on disconnect is coming out of the pump hose rather than the tire (that's because as long as your pulling the head off the valve cleanly the pressure inside the tube is keeping the valve closed).
  • 02-26-2005
    baking3
    Spit!
    Ah...spit! That universal biodegradable lubricant! I should have thought of that. It's also good for keeping the inside of your scuba mask from fogging up...

    The pressure loss wasn't happening every time. I have a feeling that I just haven't been getting the pump off smoothly enough to allow the valve to seal quickly.

    Thanks!

    bak
  • 02-26-2005
    Al1943
    If you have some silicone or teflon based lubricant try putting a little of it on the rubber "O" ring in the chuck head. I'm switching to Michelin tubes because they have no threads on the outside of the stems, so the pump chuck slides off easier.

    Al