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#1
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help needed with presta valves please!
I've got a bike problem. I've bought a bike with presta valve tubes.
I am used to schrader valves. I went out and bought a large hand (detonator type) pump, and the shop also gave me this little metal adaptor, which I can screw into a Schrader valve pump, and should then work on my presta tubes. It's really not that easy. Firsly, when I am using my new pump, I find it really hard to get an initial reading before I start pumping. And when I am done, I have REAL trouble pulling the end of the pump off the valve. I've made sure I take it off lock-mode, but I have to pull really hard for the thing to come off, which it does in the end, but lets out LOADS of air (and I often hurt my hand after it hitting to spokes!). Can anyone tell me what the problem is here?! and if there are any really good pumps for the presta valve? I am so used to the Schrader valve, it was much easier! Thanks, Paul |
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#2
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help needed with presta valves please!
"Paul Turner" wrote:
I've bought a bike with presta valve tubes. I am used to schrader valves. I went out and bought a large hand (detonator type) pump, and the shop also gave me this little metal adaptor, which I can screw into a Schrader valve pump, and should then work on my presta tubes. Cut off the chuck at the end of the hose, and replace it with a brass Silca Presta chuck using a hose clamp. http://www.sheldonbrown.com/harris/tools-h-z.html#pump Before pumping, loosen the screw fitting on the valve, and give it a quick tap to free it up. Now attach the Silca head and pump. Using this method, I can top off a tire in a few seconds with no lost air. BTW, I use a silca track pump: http://tinyurl.com/dtqmz Art Harris |
#3
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help needed with presta valves please!
On 4 Jul 2005 06:35:18 -0700, "Paul Turner"
wrote: I've got a bike problem. I've bought a bike with presta valve tubes. I am used to schrader valves. I went out and bought a large hand (detonator type) pump, and the shop also gave me this little metal adaptor, which I can screw into a Schrader valve pump, and should then work on my presta tubes. It's really not that easy. Firsly, when I am using my new pump, I find it really hard to get an initial reading before I start pumping. And when I am done, I have REAL trouble pulling the end of the pump off the valve. I've made sure I take it off lock-mode, but I have to pull really hard for the thing to come off, which it does in the end, but lets out LOADS of air (and I often hurt my hand after it hitting to spokes!). Can anyone tell me what the problem is here?! and if there are any really good pumps for the presta valve? I am so used to the Schrader valve, it was much easier! The most common type of adapter is a brass bit about half an inch long which gets *screwed* onto the Presta valve. It's next to impossible to check the pressure in a Presta-equipped tire in my experience; you end up getting good at estimating the pressure via thumb and forefinger. The inflation procedure for me goes this way: - Remove dust cap and unscrew adapter from Presta valve (I keep the adapters on the bike.) - Loosen Presta valve nut and wiggle stem to break seal. - Screw adapter back on to Presta valve. - Clamp tire pump or hose connector on to adapter (if using a hand pump with a Schrader chuck) and inflate, or use air hose with standard Schrader valve inflation chuck if inflating from a compressor. - Disconnect hose or pump from adapter. - Unscrew adapter, tighten locknut, replace adapter and dust cap, feel pressure, and ride. -- Typoes are a feature, not a bug. Some gardening required to reply via email. Words processed in a facility that contains nuts. |
#4
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help needed with presta valves please!
I've never had much good luck with that adaptor either. It's not a bad
thing to carry for an emergency, but for routine use, it's a pain! I've not been all that happy with the big brass Silca chucks, either, but some folks swear by them! Topeak has a nice "smart head" chuck and hose which can be (somehow) fitted to your pump. It automagically adapts to either Presta or Schrader valves. I've not acually used this one, but my pump is a T-headed Topeak. Topeak has a reputation for great customer service, too. Paul Turner wrote: I've got a bike problem. I've bought a bike with presta valve tubes. I am used to schrader valves. I went out and bought a large hand (detonator type) pump, and the shop also gave me this little metal adaptor, which I can screw into a Schrader valve pump, and should then work on my presta tubes. |
#5
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help needed with presta valves please!
"Paul Turner" wrote:
I've got a bike problem. I've bought a bike with presta valve tubes. I am used to schrader valves. I went out and bought a large hand (detonator type) pump, and the shop also gave me this little metal adaptor, which I can screw into a Schrader valve pump, and should then work on my presta tubes. It's really not that easy. Firsly, when I am using my new pump, I find it really hard to get an initial reading before I start pumping. Loosen lock nut, crack the seal and then put your adaptor on. Wes -- Reply to: Whiskey Echo Sierra Sierra AT Alpha Charlie Echo Golf Romeo Oscar Paul dot Charlie Charlie Lycos address is a spam trap. |
#6
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help needed with presta valves please!
Concur... IMO, this kind of chuck (or head) is THE ONLY WAY TO GO for
home or shop use. I've an old, reliable floor pump (Husky Zefal, similar to the Silca model linked to and available at CC) and I upgraded it years ago with a presta-only valve chuck just like the one pointed out. Now it takes only a few moments to top off the tires when I'm on the way out the door -- no fuss, just air. Just push the chuck over the valve stem (with the valve side of the tire to the ground), pump to desired pressure, and pull the chuck off. Any pressure -- no problem. ( http://www.sheldonbrown.com/harris/tools-h-z.html#pump ) No manual actuation of the chuck is required because the internal rubber bushing (which is under some pre-load compression by the female-threaded knurled retaining collar) provides an air-tight seal and sufficient grip around the valve stem to stay in place when you are pumping. As air pressure on the tube-side of the bushing inceases, so does the friction exerted by the bushing against the stem proportionately increase. Thus, you don't have to hold the chuck in place when inflating the tire and the chuck remains easy to remove with a gentle tug, even at higher tire pressures. After hundreds of sessions over a period of years, the original rubber bushing in the head is looking a little shredded. It still works perfectly, but I note I can order a replacement bushing with my next parts procurement from Harris Cyclery. /* Mykal */ |
#7
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help needed with presta valves please!
mykal wrote:
Concur... IMO, this kind of chuck (or head) is THE ONLY WAY TO GO for home or shop use. I've an old, reliable floor pump (Husky Zefal, similar to the Silca model linked to and available at CC) and I upgraded it years ago with a presta-only valve chuck just like the one pointed out. Now it takes only a few moments to top off the tires when I'm on the way out the door -- no fuss, just air. Just push the chuck over the valve stem (with the valve side of the tire to the ground), pump to desired pressure, and pull the chuck off. Any pressure -- no problem. ( http://www.sheldonbrown.com/harris/tools-h-z.html#pump ) No manual actuation of the chuck is required because the internal rubber bushing (which is under some pre-load compression by the female-threaded knurled retaining collar) provides an air-tight seal and sufficient grip around the valve stem to stay in place when you are pumping. As air pressure on the tube-side of the bushing inceases, so does the friction exerted by the bushing against the stem proportionately increase. Thus, you don't have to hold the chuck in place when inflating the tire and the chuck remains easy to remove with a gentle tug, even at higher tire pressures. After hundreds of sessions over a period of years, the original rubber bushing in the head is looking a little shredded. It still works perfectly, but I note I can order a replacement bushing with my next parts procurement from Harris Cyclery. Good summary. A presta valve can 'stick' closed. Tapping the valve stem with a finger(after unscrewing the knurled nut, before pressing the pump head on) is a good habit. It is not obvious to everyone that installation of the Silca brass head involves slicing the hose just before whatever crimp secured your original head. Use a stainless hose clamp with your new head. The internal rubber washer is a good fit when new. As it wears, tighten the end cap to compress the washer. Overtightening that cap makes sliding the head over your valve difficult and wears the washer faster - easy does it. -- Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971 |
#8
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help needed with presta valves please!
I second the idea to get a Topeak pump head or a new Topeak pump. I
find mine to be way more easy to use and reliable than the traditional "press on and pray Silca." The Topeak locks on and you never have to hold it on with one hand and pump with the other. Delightful customer service...as mentioned above. |
#9
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help needed with presta valves please!
Paul Turner wrote:
I've got a bike problem. I've bought a bike with presta valve tubes. I am used to schrader valves. I went out and bought a large hand (detonator type) pump, and the shop also gave me this little metal adaptor, which I can screw into a Schrader valve pump, and should then work on my presta tubes. It's really not that easy. Firsly, when I am using my new pump, I find it really hard to get an initial reading before I start pumping. And when I am done, I have REAL trouble pulling the end of the pump off the valve. I've made sure I take it off lock-mode, but I have to pull really hard for the thing to come off, which it does in the end, but lets out LOADS of air (and I often hurt my hand after it hitting to spokes!). Can anyone tell me what the problem is here?! and if there are any really good pumps for the presta valve? I am so used to the Schrader valve, it was much easier! Are you sure your pump is intended for Schrader valves? If it's *really* hard to pull the pump off the valve, maybe your pump head is intended for presta valves. If so, you shouldn't be using the adapter. One of the benefits of the presta valve is that you don't lose any air when you pull the pump off the valve. I wonder if the escaping air that you mention is coming from the tube or the pump. Is the tire noticeably softer after the "loads of air" escape? As others have mentioned, let a little air out of the tube before you hook up the pump. That will free up the valve, which tends to get stuck in place after a while. -- Dave dvt at psu dot edu |
#10
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help needed with presta valves please!
Don't unscrew the valve all the way, just loosen it enough so air comes out
when you tap the valve. Many connections tend to leak if the valve is unscrewed too far. Tom "dvt" wrote in message ... Paul Turner wrote: I've got a bike problem. I've bought a bike with presta valve tubes. I am used to schrader valves. I went out and bought a large hand (detonator type) pump, and the shop also gave me this little metal adaptor, which I can screw into a Schrader valve pump, and should then work on my presta tubes. It's really not that easy. Firsly, when I am using my new pump, I find it really hard to get an initial reading before I start pumping. And when I am done, I have REAL trouble pulling the end of the pump off the valve. I've made sure I take it off lock-mode, but I have to pull really hard for the thing to come off, which it does in the end, but lets out LOADS of air (and I often hurt my hand after it hitting to spokes!). Can anyone tell me what the problem is here?! and if there are any really good pumps for the presta valve? I am so used to the Schrader valve, it was much easier! Are you sure your pump is intended for Schrader valves? If it's *really* hard to pull the pump off the valve, maybe your pump head is intended for presta valves. If so, you shouldn't be using the adapter. One of the benefits of the presta valve is that you don't lose any air when you pull the pump off the valve. I wonder if the escaping air that you mention is coming from the tube or the pump. Is the tire noticeably softer after the "loads of air" escape? As others have mentioned, let a little air out of the tube before you hook up the pump. That will free up the valve, which tends to get stuck in place after a while. -- Dave dvt at psu dot edu |
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