Can mini pumps damage valves?
Discussion
Okay this is really annoying me.
Go to get the bike out a couple of days after topping the rear tyre up, and it's flat. This has happened to the separate front and rear tubes before. I'm using a mini pump to pump it up, with the head connecting straight onto the valve. The tubes never have any obvious leaks upon inspection, so the only explanation I can see is that the movement of the pump head is screwing up the valve. Is this feasible? If so I'm pretty annoyed, it seems unreasonable to me to sell a pump that would damage the valve but caveat emptor I guess. Or am I due an ambwilans moment?
Go to get the bike out a couple of days after topping the rear tyre up, and it's flat. This has happened to the separate front and rear tubes before. I'm using a mini pump to pump it up, with the head connecting straight onto the valve. The tubes never have any obvious leaks upon inspection, so the only explanation I can see is that the movement of the pump head is screwing up the valve. Is this feasible? If so I'm pretty annoyed, it seems unreasonable to me to sell a pump that would damage the valve but caveat emptor I guess. Or am I due an ambwilans moment?
Had the exact same problem with some tubes a while ago, using a mini-pump on Presta valves (the thin ones, not the car-type ones). I found it difficult to keep the mini pump dead central, which resulted in the central pin becoming bent over time. Eventually it went and would not retain air.
I bought a track pump and no longer have a problem. I do prefer Schrader valves for robustness though, but my current rims can no accommodate their wide valves.
I bought a track pump and no longer have a problem. I do prefer Schrader valves for robustness though, but my current rims can no accommodate their wide valves.
paranoid airbag said:
Okay this is really annoying me.
Go to get the bike out a couple of days after topping the rear tyre up, and it's flat. This has happened to the separate front and rear tubes before. I'm using a mini pump to pump it up, with the head connecting straight onto the valve. The tubes never have any obvious leaks upon inspection, so the only explanation I can see is that the movement of the pump head is screwing up the valve. Is this feasible? If so I'm pretty annoyed, it seems unreasonable to me to sell a pump that would damage the valve but caveat emptor I guess. Or am I due an ambwilans moment?
Yup, seen it happen. I think it's down to a bad connection between pump and valve and/or just mashing away too hard on said pump. Your best bet is either being a bit more gentle, or opting for a Lezyne pump (which have a small hose concealed in the body of the pump.Go to get the bike out a couple of days after topping the rear tyre up, and it's flat. This has happened to the separate front and rear tubes before. I'm using a mini pump to pump it up, with the head connecting straight onto the valve. The tubes never have any obvious leaks upon inspection, so the only explanation I can see is that the movement of the pump head is screwing up the valve. Is this feasible? If so I'm pretty annoyed, it seems unreasonable to me to sell a pump that would damage the valve but caveat emptor I guess. Or am I due an ambwilans moment?
http://www.wiggle.co.uk/lezyne-pressure-drive-mini...
After witnessing a couple of ripped-off valves in short shrift, when it came to buying myself a small pump I went for one with a tube attachment. For one of my bikes I've got a Topeak minimorph, and the other a Turbomorph.
My frames are small-sized and I could only get a short pump on the city-bike but it has 700c tyres so it's not a problem. The MTB needs a longer pump (or I'd be pumping it up forever) which is why I bought the Turbomorph too.
My frames are small-sized and I could only get a short pump on the city-bike but it has 700c tyres so it's not a problem. The MTB needs a longer pump (or I'd be pumping it up forever) which is why I bought the Turbomorph too.
bought a lezyne pump 
assuming the max. 120psi one will do me fine? I usually go up to 100psi, so 20psi should be enough of a safety margin (I know it's the flexible hose that's important here, but I've had cheapo pumps fail to reach a half-decent pressure before)
some things I can be bothered with mechanical sympathy, others I just... can't. Interim plan until that arrives is to scab a mate's track pump.
assuming the max. 120psi one will do me fine? I usually go up to 100psi, so 20psi should be enough of a safety margin (I know it's the flexible hose that's important here, but I've had cheapo pumps fail to reach a half-decent pressure before)some things I can be bothered with mechanical sympathy, others I just... can't. Interim plan until that arrives is to scab a mate's track pump.
Need to get one of those Lezyne pumps, lost count of the number of valves i have snapped over the years changing tubes at the side of the road with a mini pump. Bad tempered hamfistedness + an impatience to get going again = snapped valve... Or if not a bent one which gets you home but ultimately needs replacing.
Always use a track pump at home which prevents the problem.
Always use a track pump at home which prevents the problem.
paranoid airbag said:
bought a lezyne pump assuming the max. 120psi one will do me fine? I usually go up to 100psi, so 20psi should be enough of a safety margin (I know it's the flexible hose that's important here, but I've had cheapo pumps fail to reach a half-decent pressure before)
some things I can be bothered with mechanical sympathy, others I just... can't. Interim plan until that arrives is to scab a mate's track pump.
You'll be pumping like an utter b assuming the max. 120psi one will do me fine? I usually go up to 100psi, so 20psi should be enough of a safety margin (I know it's the flexible hose that's important here, but I've had cheapo pumps fail to reach a half-decent pressure before)some things I can be bothered with mechanical sympathy, others I just... can't. Interim plan until that arrives is to scab a mate's track pump.
d (f'nar!) to get to 100psi, but it'll do FWIW if it's for home use (as opposed to on-the-road), a track pump is money well spent.
http://www.wiggle.co.uk/topeak-joe-blow-sport-ii-t...
Gassing Station | Pedal Powered | Top of Page | What's New | My Stuff