When I was a kid growing up on the farm we had an aluminm "air bubble" that we would connect to the shop air compressor and fill to like 320 PSI. it would re-inflate 2 trailer tires. (the pipe trailer is what we used it for mostly. I wonder if anyone has already thought of this/patented it: Instead of busting out for CO2 cartriges, and instead of packing along a pump, couldn't a bike designer make sure the frame is air-tight, and put a standard valve stem on it somewhere. I know some people don't have high-pressure air compressors, but some of us do. If you could pressurize your frame to like 300 psi, you could probably refill 2 tires to 60 psi, (I didn't do any volume math here, just had the idea and started runnning my pie hole) all you would neet to bring along would be a air hose (with regulator if you are planning on being able to reinflate more than one tire, a straight hose would work if you had done the math to calculate exacly 60 psi left in both frame and tire)to connect the frame to the front or rear, and the upkeep cost would be basically 0, as opposed to buying new C02 cartriges. Just pressurize your frame before you take off.
I guess altitude would also have a little to do with it too because of the tire's inital uninflated pressure.
"x1134x" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
When I was a kid growing up on the farm we had an aluminm "air bubble" that we would connect to the shop air compressor and fill to like 320 PSI. it would re-inflate 2 trailer tires. (the pipe trailer is what we used it for mostly. I wonder if anyone has already thought of this/patented it: Instead of busting out for CO2 cartriges, and instead of packing along a pump, couldn't a bike designer make sure the frame is air-tight, and put a standard valve stem on it somewhere. I know some people don't have high-pressure air compressors, but some of us do. If you could pressurize your frame to like 300 psi, you could probably refill 2 tires to 60 psi, (I didn't do any volume math here, just had the idea and started runnning my pie hole) all you would neet to bring along would be a air hose (with regulator if you are planning on being able to reinflate more than one tire, a straight hose would work if you had done the math to calculate exacly 60 psi left in both frame and tire)to connect the frame to the front or rear, and the upkeep cost would be basically 0, as opposed to buying new C02 cartriges. Just pressurize your frame before you take off.
I guess altitude would also have a little to do with it too because of the tire's inital uninflated pressure.
IT would be hell if you crashed and cracked the frame, especially the top tube, goodby future family. 320psi of air pressure would be a bomb going off. For the cost to do this you can buy a lot of CO2 at Wallmart at about 50 cents each.
the cost of doing it, provided the frame is already air tight, would be drilling a hole, tapping it, some sealant tape and a valve-stem. At most 5 bucks. Just rent/borrow a tap/die set from homedepot.
I don't think venting that SMALL volume of air even @ 300 would be that damaging especially if its being vented out a LARGE crack. It would simply go [censored]! Although it might propel any shrapnel that broke loose from the crack toward your eyes.
Nice idea, but have you thought about the condensation that would build up with all the charging/discharging? I think you'd have to use an aluminum frame, and add a petcock valve to drain the water.
When I was a kid growing up on the farm we had an aluminm "air bubble" that we would connect to the shop air compressor and fill to like 320 PSI. it would re-inflate 2 trailer tires. (the pipe trailer is what we used it for mostly. I wonder if anyone has already thought of this/patented it: Instead of busting out for CO2 cartriges, and instead of packing along a pump, couldn't a bike designer make sure the frame is air-tight, and put a standard valve stem on it somewhere. I know some people don't have high-pressure air compressors, but some of us do. If you could pressurize your frame to like 300 psi, you could probably refill 2 tires to 60 psi, (I didn't do any volume math here, just had the idea and started runnning my pie hole) all you would neet to bring along would be a air hose (with regulator if you are planning on being able to reinflate more than one tire, a straight hose would work if you had done the math to calculate exacly 60 psi left in both frame and tire)to connect the frame to the front or rear, and the upkeep cost would be basically 0, as opposed to buying new C02 cartriges. Just pressurize your frame before you take off.
I guess altitude would also have a little to do with it too because of the tire's inital uninflated pressure.
Better yet, Fill it with O2 and bring a cannula. Everyone would think you were some sort of suicidal heart patient, till you wax them on the first climb! <removes tongue from cheek>
Nice idea, but have you thought about the condensation that would build up with all the charging/discharging? I think you'd have to use an aluminum frame, and add a petcock valve to drain the water.
I don't think I could stand the ridicule from my peers if they found out I had to blow down my frame.
"x1134x" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
When I was a kid growing up on the farm we had an aluminm "air bubble" that we would connect to the shop air compressor and fill to like 320 PSI. it would re-inflate 2 trailer tires. (the pipe trailer is what we used it for mostly. I wonder if anyone has already thought of this/patented it: Instead of busting out for CO2 cartriges, and instead of packing along a pump, couldn't a bike designer make sure the frame is air-tight, and put a standard valve stem on it somewhere. I
IT would be hell if you crashed and cracked the frame, especially the top tube, goodby future family. 320psi of air pressure would be a bomb going off.
LOL. My thoughts exactly. I'm no engineer but I'm sure that there are some interesting things that need to be considered - not the least of which would be the structural strength of a straight piece of tubing. Surely the walls would bulge outwards?
Mountain biking can be dangerous enough without your bike being a pipebomb as well.
Still, might pay to patent it.... you never know. -- Westie
Better yet, Fill it with O2 and bring a cannula. Everyone would think you were some sort of suicidal heart patient, till you wax them on the first climb!
"x1134x" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
the cost of doing it, provided the frame is already air tight, would be drilling a hole, tapping it, some sealant tape and a valve-stem. At most 5 bucks. Just rent/borrow a tap/die set from homedepot.
I don't think venting that SMALL volume of air even @ 300 would be that damaging especially if its being vented out a LARGE crack. It would simply go [censored]! Although it might propel any shrapnel that broke loose from the crack toward your eyes.
It would not be a small volume at 300psi, and it would not go "[censored]", it would be a big "boom". A few years ago our shop nearly had two welders killed by a 4" pipe about 4' long that had been sealed at both ends, they were heating it up in a oven, blew the entire thing over the shop. Small pieces of metal were in everything, both were lucky, only suffering some hearing damage. Compressed air is very dangerous, unlike hydraulic fluid which cannot be compressed and pressure will quickly go to zero is a small leak occurs, a small leak with compressed air becomes a large leak in a matter of milliseconds.
"x1134x" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
When I was a kid growing up on the farm we had an aluminum "air bubble" that we would connect to the shop air compressor and fill to like 320 PSI. it would re-inflate 2 trailer tires. SNIP cartridges. Just pressurize your frame before you take off.
I guess altitude would also have a little to do with it too because of the tire's initial uninflated pressure.
Instead of pressurizing the frame why not put a canister inside one of the frame tubes. I vote for the downtube and a 60-40 split of the profit..
-- DTW .../\.../\.../\...
I've spent most of my money on mountain biking and windsurfing. The rest, I've just wasted.
Better yet, Fill it with O2 and bring a cannula. Everyone would think you were some sort of suicidal heart patient, till you wax them on the first climb!
I could of used that in Idaho.
Why? There was plenty of air up there! oh wait, no there wasn't.....
Better yet, Fill it with O2 and bring a cannula. Everyone would think you were some sort of suicidal heart patient, till you wax them on the first climb!
I could of used that in Idaho.
Why? There was plenty of air up there! oh wait, no there wasn't.....
Gary
It wasn't really the altitude as much as the length of the climbs and the hike-a-bike on shale trails.
What do you think/know about Salem, Oregon? There's an opportunity that might present itself in the next few days. It would be a huge career move among other things. I know there is a "moisture" problem in the PNW, but I saw a house perched on the edge of Williamette (?) forest that could keep things looking so green I could easily overlook the wetness.
Like I said My experience comes from the shop compressor @ 320 psi. We had numerous rubber hoses blow after some dipcrap ran over it with farm machinery, or just from age, and it raises quite a ruckus but is nowhere near bomb-like.
My physics brain also says that if you heat a sealed pipe in an oven the pressure inside the pipe should increase proportionally with the air pressure in the oven, and regardless of the temperature it shouldn't press outward on the walls of the pipe at all. (unless the oven has a vent to outside)
How about just tacking on a small aluminum tank that is designed to take it?
No way, our aluminum air bubble was a propane tank modified for farm air-tank. its walls were way thinner than my BSO's let alone a good bike. It had a one way valve on one side so you could connect it directly to the big compressor, and it would fill to 320 in like 4 seconds.
That would make it like what, 1 microgram lighter? If you try to suck the air out of a 50 gallon oil drum, the weight of the atmosphere and the associated pressure will crush the drum like it's a pop can.
My physics brain also says that if you heat a sealed pipe in an oven the pressure inside the pipe should increase proportionally with the air pressure in the oven, and regardless of the temperature it shouldn't press outward on the walls of the pipe at all. (unless the oven has a vent to outside)
Quite true. This kind of sealed "pressure oven" is used extensively in the aircraft industry for baking titanium at 5-6000 PSI to increase its molecular density. I think it's a little pricey for bike frames, though.
