Vit
Bike Commuter
4 years smoke free
Posts: 56
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Post by Vit on May 20, 2007 13:57:11 GMT 8
I have had a my road bike for 3 years now, and I found that inflating the tire to 90-100 psi is not an easy task. In fact, I think I have overstrained myself, particularly my left upper body & arm in doing so. I feel some discomfort/ mild pain now on this region of my body. I use a small MOB pump (which is great for mountain bike tires ) to pressure up the tires.
What kind of pump do you use for your road tires? Anybody ever had same overstrain before?
Vit
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edededed
Urban Assaulter
para sa pagdating ng balang araw
Posts: 84
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Post by edededed on May 20, 2007 15:05:57 GMT 8
i use a floor pump, it's so much easier to reach 100psi (floor pump can do as much as 160 psi i think). but if im on the road,i carry a small giyo pump (almost the same as MOB)
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Post by Dragunov on May 20, 2007 15:19:46 GMT 8
you can use a CO2 cartridge type inflator for emergencies and use a foot pump or a floor pump when your at home, its really hard to inflate a road tire with a handpump, another solution is to head to your gym and pump your muscles hehehe
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Post by mountguitars on May 20, 2007 21:13:20 GMT 8
you can use a CO2 cartridge type inflator for emergencies and use a foot pump or a floor pump when your at home, its really hard to inflate a road tire with a handpump, another solution is to head to your gym and pump your muscles hehehe i wouldnt bet on a CO2 inflator. i think you need a high pressure tire pump. an MOB or giyo typical pump will never do. if pumping air on MTB tires using MOB gives me problems, i sure wouldnt use it on a road bike.
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Post by allegra on May 20, 2007 21:34:00 GMT 8
I'm a big guy so I inflate mine to 120psi Tried the mob hand pump didnt injure myself but I bent the valve on the tire Get the big expensive bike pump, it's definitely worth the money Coz I bought the cheap floor pump and I still keep breaking the plastic parts
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Post by enzo on May 20, 2007 22:39:56 GMT 8
Vit,
Try Topeak Mountain or Road Morph pump. It can reach 120 PSI. I even use to inflate my road tires. Its actually a foot pump disguising as a mini pump. It has a gauge, a foot hold, the handle is tiltable so iyou have a nice grip, and when you lock the nozzle to the valve, you only put pressure on the handle so you wont break it. Sometimes I forgot I have a floor pump coz its as handy.
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Post by Ben Dover on May 21, 2007 9:38:44 GMT 8
bought a MOB floor pump with gauge for home use...well made and for around P600.oo plus i think its the best value for money...i have a SKS (german) hand pump that i carry during rides..its expensive, heavy and hard to use.
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Post by mountguitars on May 21, 2007 9:48:36 GMT 8
vit,
do you use a floorpump at home? if not you better get one coz its really indespensable for mountainbikes and roadbikes alike. i even use it to fill our van's tires.
if you're talking about repairs on road, a floor pump would be challenging to bring along. ;D . are you looking for a portable road tire pump?
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Post by allegra on May 21, 2007 10:51:15 GMT 8
bought a MOB floor pump with gauge for home use...well made and for around P600.oo plus i think its the best value for money...i have a SKS (german) hand pump that i carry during rides..its expensive, heavy and hard to use. thats the same brand I bought hehe I keep breaking the lever dun sa pangkabit sa valve ( whatever it's called ) Roadbike tires are a pain in the rear
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Post by wcoastbo on May 21, 2007 13:37:59 GMT 8
Try Topeak Mountain or Road Morph pump. I 2nd enzo's suggestion. This is an excellent pump for its size. Not a weight weenie pump (a bit bulky when mounted on the frame), but small enough to put inside most hydration packs. Well designed and easy to use. Micro mini pumps are only good for occasional trailside/roadside repairs, not for daily use. The Morph is a good compromise if you only want to buy one pump. I keep one in my car and use it as a travel pump. I'm not a big fan of micro pumps and use an old skool style frame pump on my roadbike
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Post by enzo on May 21, 2007 14:04:00 GMT 8
Wcoastbo,
I use the same frame mounted road pump. Its easy and you know we dont carry backpack so its really handy and have saved my rides lots of times. I just take a different approach in using it by gripping the tires with my palm and holding the end of the pump with my forefingers to minimize valve breaking. The tendency is that we put a lot of pressure when we pump these presta valved tubes and they collapsed at the valve seat itself, where the rubber and valve connects.
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Post by Ben Dover on May 21, 2007 14:57:05 GMT 8
bought a MOB floor pump with gauge for home use...well made and for around P600.oo plus i think its the best value for money...i have a SKS (german) hand pump that i carry during rides..its expensive, heavy and hard to use. thats the same brand I bought hehe I keep breaking the lever dun sa pangkabit sa valve ( whatever it's called ) Roadbike tires are a pain in the rear the MOB floor pump was recommended by roadie friend and fortunately for me, i havent broken the lever yet..but seeing jon's post, looks like there really is a serious flaw with its lever design...i kinda like MOB's...you need a lighter effort to push the pump..i usually borrow one to fix my tire (MTB) than to use my SKS
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Vit
Bike Commuter
4 years smoke free
Posts: 56
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Post by Vit on May 21, 2007 21:26:06 GMT 8
thanks guys...I have every reason to invest on a floor pump now. Otherwise, I wont be able to use the road bike. The tires are soft again and I dont think I want to use the MOB pump for high pressure ( I need to find a therapist for my left side pain )
Funny thing is that the tires need pumping everytime...like in less than a week
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Post by enzo on May 21, 2007 21:34:32 GMT 8
Vit,
Of course, air contains 20% water so they lose pressure.
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Post by king on May 21, 2007 22:08:59 GMT 8
oh i thought it was because tires and tubes actually still have microscopic holes in them, and not exactly 100% airtight valves, through which air molecules escape over time...
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Post by enzo on May 21, 2007 22:32:57 GMT 8
Some locals here are suggesting to put nitrogen, coz they dont lose pressure. They use it with their 4x4 coz they stay at the same pressure regardless of temperature change. Expensive for vehicles but they last long. It would be an overkill if we put it in our tires though its actually good. They do have some micro holes and your right, but most models now have more denser rubber so its almost if not 100% airtight. Like in some models they have 127 TPI casing in some less. But the real culprit is water. Or I may be wrong.
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Post by jr on May 21, 2007 23:13:34 GMT 8
I also have same pump similar with Bo and enzo. Fit to the bike frame.
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Post by wcoastbo on May 22, 2007 0:52:45 GMT 8
Funny thing is that the tires need pumping everytime...like in less than a week I like to maintain consistent air pressure in my tires. As the others mentioned you're going to lose air pressure due to seepage. Even car tires with their thick casing needs to be checked every couple of months. You'll find that low pressure, high volume tires (mtb) can sustain consistent tire pressure over a longer period of time (several days depending on your tube/tires). High pressure, low volume tires (road) can only sustain consistent pressure for a day or two. I prefer to top off my road tires before each ride at 110 psi. Even this weekend when I did back to back sat & sun rides. I lost about 10 psi over a 24 hour period.
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Post by rench on May 22, 2007 3:29:09 GMT 8
Wait- Air dontains 20% water? Not very likely. Air is approx 78% Nitrogen, 21% Oxygen. 1% Other gasses - CO, CO2 and water vapor among them. At normal temperatures, both behave as ideal gasses, following the ideal gas law, PV=nRT. It doesn't matter if your tires are filled with nitrogen or air, the increase in volume or pressure would be the same.
The rate of diffusion through a permiable membrame would depend on molar mass and if the gasses O2 or N2 were to diffuse though the tire, N2 would diffuse faster due to its lighter mass.
N2 and O2 both have essentially the same specific heat capacity, about 1.0 J/gK, and thermal conductivity, about 0.00026 W/cmK. Water vapor has a specific heat capacity of about 2 J/gK. But remember, water vapor will constitute less than 1% of the air in the tire. So the idea that N2 has different heat handling properties is also without merit.
I guess nitrogen would be handy to have among aircraft and racecars because a canister of high pressure nitrogen is more convenient to move around than a compressor.
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Post by cobym on May 22, 2007 7:23:07 GMT 8
Nice... now thats what I call a scholarly post. I agree 100%.
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Post by king on May 22, 2007 7:39:23 GMT 8
nards, i see you googled it as well ;D Wait- Air dontains 20% water? Not very likely. Air is approx 78% Nitrogen, 21% Oxygen. 1% Other gasses - CO, CO2 and water vapor among them. At normal temperatures, both behave as ideal gasses, following the ideal gas law, PV=nRT. It doesn't matter if your tires are filled with nitrogen or air, the increase in volume or pressure would be the same. The rate of diffusion through a permiable membrame would depend on molar mass and if the gasses O2 or N2 were to diffuse though the tire, N2 would diffuse faster due to its lighter mass. N2 and O2 both have essentially the same specific heat capacity, about 1.0 J/gK, and thermal conductivity, about 0.00026 W/cmK. Water vapor has a specific heat capacity of about 2 J/gK. But remember, water vapor will constitute less than 1% of the air in the tire. So the idea that N2 has different heat handling properties is also without merit. I guess nitrogen would be handy to have among aircraft and racecars because a canister of high pressure nitrogen is more convenient to move around than a compressor.
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Post by mountguitars on May 22, 2007 10:32:08 GMT 8
nards, i see you googled it as well ;D Wait- Air dontains 20% water? Not very likely. Air is approx 78% Nitrogen, 21% Oxygen. 1% Other gasses - CO, CO2 and water vapor among them. At normal temperatures, both behave as ideal gasses, following the ideal gas law, PV=nRT. It doesn't matter if your tires are filled with nitrogen or air, the increase in volume or pressure would be the same. The rate of diffusion through a permiable membrame would depend on molar mass and if the gasses O2 or N2 were to diffuse though the tire, N2 would diffuse faster due to its lighter mass. N2 and O2 both have essentially the same specific heat capacity, about 1.0 J/gK, and thermal conductivity, about 0.00026 W/cmK. Water vapor has a specific heat capacity of about 2 J/gK. But remember, water vapor will constitute less than 1% of the air in the tire. So the idea that N2 has different heat handling properties is also without merit. I guess nitrogen would be handy to have among aircraft and racecars because a canister of high pressure nitrogen is more convenient to move around than a compressor. nyahahaha. ;D i almost thought we have a scientist in da house. ;D
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Post by rench on May 22, 2007 12:32:55 GMT 8
king, i did get passing grades in chem. and yeah, i know how to use google.
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Post by enzo on May 22, 2007 14:24:51 GMT 8
Rench,
I just consulted some guys working at the Dubai autodrome and some mechanics from Kaeser Compressors about that water percentage or moisture. They said that air coming from compressors contain more moisture due to condensation. I just tinkered with my compressor and yes, there's water at the bottom of the cylinder which he said I must drain every now and then. and which goes out with the compressed air to our tubes every time we use it. Even up to 20% is possible, or maybe that was a higher or rough estimate. With hand pump is different. Anybody of you have compressors and check it yourself, or maybe its just here due to the humidity being sucked from the air or atmosphere as he stated. Im going to do a test by putting an overinflated tube and put it in a glass container filled with water, top it off, and sealed it. I will even turn it upside down and see if there are escaping air. If it will escape, it will only float up and stay t the top of the upside down bottle(to view it easily),and see how fast or how much air will escape in time. If the tube deflates and no air in the water filled bottle, then the culprit is water or moisture. Lets see. Im going to ask for the nitrogen filled car tires next time.
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Post by warlock^_^ on May 22, 2007 18:08:44 GMT 8
enlightening! hehehe I'm chemical engineer and this is really interesting. Oh by the way...I have the Topeak Mountain Morph....no gauge, the Turbo version has one.
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Post by enzo on May 22, 2007 18:22:04 GMT 8
Warlock,
As good as the turbo, the pressure gauge is not accurate anyway. One time when we were trailing, one brad( American) fltted and his brad gave him his pump. Running to the rescue from afar, I approached them and handed my pump even if they are already starting to inflate it. He said,"this is actually a pefectly good pump" And I said this is better. after the demonstration, he said I was right. With a small pump, you need to pump it more than 100 times to reach 40 PSI. With the morph, half of it only.
What do you think of this TEST?
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Vit
Bike Commuter
4 years smoke free
Posts: 56
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Post by Vit on May 22, 2007 21:49:26 GMT 8
Rench, Im going to do a test by putting an overinflated tube and put it in a glass container filled with water, top it off, and sealed it. I will even turn it upside down and see if there are escaping air. If it will escape, it will only float up and stay t the top of the upside down bottle(to view it easily),and see how fast or how much air will escape in time. If the tube deflates and no air in the water filled bottle, then the culprit is water or moisture. . My bet is that if the tire deflates, it would be due to air bubbles escaping. All materials have certain permeabilities. And I guess (tamad mag-google) for the rubber tube this permeability improves as it is stretched more at higher pressures. That's why lower pressure mtb tires stay inflated longer. And, I suspect (tamad mag-google pa rin) nitrogen (N2) may be a bigger molecule than O2 (19% of air? ) such that for same permeability of container, nitrogen filled one will stay in pressure longer
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Post by warlock^_^ on May 23, 2007 3:12:06 GMT 8
What do you think of this TEST? yeah, enzo...but still beat us since they can lug it on their jersey's back pocket ;D I cant strap mine on the frame... I got a small bike frame (hobbit size) oh..by the way guys...drop the permeability thing. All the losses are always thru the valves.
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Post by rench on May 23, 2007 3:36:52 GMT 8
warlock, i agree with you there. Besides, the original poster was asking how to pump up the high pressure tires without injuring oneself. And that point has been answered - good floor pumps, and CO2 cartridges for emergencies.
I don't get enzo's experiment though. The escaping air from the tube will definitely go to the top of the bottle. but you can't be definite with the volume of the air- because gas is compressible. moreover, i can't imagine the second case - where the tire will deflate without releasing the air - unless air turns into water?
i guess we can prove that tubes leak air - but anybody with a deflated tire already knew that.
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Post by ronaldarca on May 23, 2007 5:36:01 GMT 8
What do you think of this TEST? yeah, enzo...but still beat us since they can lug it on their jersey's back pocket ;D I cant strap mine on the frame... I got a small bike frame (hobbit size) oh..by the way guys...drop the permeability thing. All the losses are always thru the valves. ;D ;D ;D now, that's simply a correct answer. ;D i like that sir butch. Happy Birthday again
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