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#1
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Commercially Available Valve Stem Mounted Puncture Alarm
https://www.dcrainmaker.com/2018/04/...re-sensor.html
It's assumed the cyclist pretty much knows what the pressure is at the beginning of a ride, and, if no punctures, that shouldn't be much more than 40 kPA different than at the end of the day. So the only interesting event that needs to be monitored is a rapid pressure drop indicating a puncture. What cyclists really need is real time ( 3 seconds) smoke detector like piezoelectric shriek when the pressure drops, say, 20 kPa over 3 seconds. It's only necessary to determine the time rate of change in pressure to alert the cyclist he has just run over a thorn. A button battery powered sensor that detects rapid changes in air pressure should be at least as cheap as one that monitors pressure itself. A fancier version could have 3 different pitches for 3 different leak rates, high for 40 kPa / 2 sec, medium for 20 kPa/3 sec and low for 7 kPa / 3 seconds. Then the cyclist has a clue as to how long it'll be before he's on the rims.. Is anything like this commercially available? On a production basis it shouldn't cost much more than a $5 smoke detector. Bret Cahill |
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#2
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Commercially Available Valve Stem Mounted Puncture Alarm
Bret Cahill wrote:
https://www.dcrainmaker.com/2018/04/...re-sensor.html It's assumed the cyclist pretty much knows what the pressure is at the beginning of a ride, and, if no punctures, that shouldn't be much more than 40 kPA different than at the end of the day. So the only interesting event that needs to be monitored is a rapid pressure drop indicating a puncture. What cyclists really need is real time ( 3 seconds) smoke detector like piezoelectric shriek when the pressure drops, say, 20 kPa over 3 seconds. It's only necessary to determine the time rate of change in pressure to alert the cyclist he has just run over a thorn. A button battery powered sensor that detects rapid changes in air pressure should be at least as cheap as one that monitors pressure itself. A fancier version could have 3 different pitches for 3 different leak rates, high for 40 kPa / 2 sec, medium for 20 kPa/3 sec and low for 7 kPa / 3 seconds. Then the cyclist has a clue as to how long it'll be before he's on the rims. Is anything like this commercially available? On a production basis it shouldn't cost much more than a $5 smoke detector. Bret Cahill I could almost feel sorry for you. But I don't. |
#3
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Commercially Available Valve Stem Mounted Puncture Alarm
On 02/11/2018 16:30, Bret Cahill wrote:
https://www.dcrainmaker.com/2018/04/...re-sensor.html It's assumed the cyclist pretty much knows what the pressure is at the beginning of a ride, and, if no punctures, that shouldn't be much more than 40 kPA different than at the end of the day. So the only interesting event that needs to be monitored is a rapid pressure drop indicating a puncture. What cyclists really need is real time ( 3 seconds) smoke detector like piezoelectric shriek when the pressure drops, say, 20 kPa over 3 seconds. It's only necessary to determine the time rate of change in pressure to alert the cyclist he has just run over a thorn. A button battery powered sensor that detects rapid changes in air pressure should be at least as cheap as one that monitors pressure itself. A fancier version could have 3 different pitches for 3 different leak rates, high for 40 kPa / 2 sec, medium for 20 kPa/3 sec and low for 7 kPa / 3 seconds. Then the cyclist has a clue as to how long it'll be before he's on the rims. Is anything like this commercially available? On a production basis it shouldn't cost much more than a $5 smoke detector. Bret Cahill BMW cars (and other makes such as Toyota, Pontiac and Cadillac) do this. Why not just buy a bike made by one (or more) of those? |
#4
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Commercially Available Valve Stem Mounted Puncture Alarm
On 02/11/2018 23:29, JNugent wrote:
On 02/11/2018 16:30, Bret Cahill wrote: https://www.dcrainmaker.com/2018/04/...re-sensor.html It's assumed the cyclist pretty much knows what the pressure is at the beginning of a ride, and, if no punctures, that shouldn't be much more than 40 kPA different than at the end of the day. So the only interesting event that needs to be monitored is a rapid pressure drop indicating a puncture. What cyclists really need is real time ( 3 seconds) smoke detector like piezoelectric shriek when the pressure drops, say, 20 kPa over 3 seconds. It's only necessary to determine the time rate of change in pressure to alert the cyclist he has just run over a thorn.Â* A button battery powered sensor that detects rapid changes in air pressure should be at least as cheap as one that monitors pressure itself. A fancier version could have 3 different pitches for 3 different leak rates, high for 40 kPa / 2 sec, medium for 20 kPa/3 sec and low for 7 kPa / 3 seconds. Then the cyclist has a clue as to how long it'll be before he's on the rims. Is anything like this commercially available?Â* On a production basis it shouldn't cost much more than a $5 smoke detector. Bret Cahill BMW cars (and other makes such as Toyota, Pontiac and Cadillac) do this. Why not just buy a bike made by one (or more) of those? all recent cars must have tyre pressure monitoring, it is a legal requirement now. Many bicycles use car size valves, it is easy to buy a set of valve caps to fit car size valves that transmit the tyre pressure to a little monitor screen, this has been available for many years and is especially really useful for trailers and caravans (where you would not so easily notice low pressure symptoms from driving feel. |
#5
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Commercially Available Valve Stem Mounted Puncture Alarm
On 03/11/2018 06:56, MrCheerful wrote:
On 02/11/2018 23:29, JNugent wrote: On 02/11/2018 16:30, Bret Cahill wrote: https://www.dcrainmaker.com/2018/04/...re-sensor.html It's assumed the cyclist pretty much knows what the pressure is at the beginning of a ride, and, if no punctures, that shouldn't be much more than 40 kPA different than at the end of the day. So the only interesting event that needs to be monitored is a rapid pressure drop indicating a puncture. What cyclists really need is real time ( 3 seconds) smoke detector like piezoelectric shriek when the pressure drops, say, 20 kPa over 3 seconds. It's only necessary to determine the time rate of change in pressure to alert the cyclist he has just run over a thorn.Â* A button battery powered sensor that detects rapid changes in air pressure should be at least as cheap as one that monitors pressure itself. A fancier version could have 3 different pitches for 3 different leak rates, high for 40 kPa / 2 sec, medium for 20 kPa/3 sec and low for 7 kPa / 3 seconds. Then the cyclist has a clue as to how long it'll be before he's on the rims. Is anything like this commercially available?Â* On a production basis it shouldn't cost much more than a $5 smoke detector. Bret Cahill BMW cars (and other makes such as Toyota, Pontiac and Cadillac) do this. Why not just buy a bike made by one (or more) of those? all recent cars must have tyre pressure monitoring, it is a legal requirement now. I didn't know that, but it makes sense. Many bicycles use car size valves, it is easy to buy a set of valve caps to fit car size valves that transmit the tyre pressure to a little monitor screen, this has been available for many years and is especially really useful for trailers and caravans (where you would not so easily notice low pressure symptoms from driving feel. Sounds like a good idea. And it would provide an opportunity for ostenatious display of the cyclist's affluence. After all, they're all Considerably Richer Than Yow. Talking of which, here's a typical ukrc cyclist: https://www.youtube.com/watch?v=U8Kum8OUTuk |
#6
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Commercially Available Valve Stem Mounted Puncture Alarm
On 02/11/2018 16:30, Bret Cahill wrote:
What cyclists really need... I really don't think I do. ... is real time ( 3 seconds) smoke detector like piezoelectric shriek when the pressure drops, say, 20 kPa over 3 seconds. Or - notice the bike is handling strangely. And shout "oh bugger" inside your head. My guess is that the device shown only does a check every few hours or days so replaces routine checking - put weight on bar and frame; do the sidewalls bulge? Your fast response adds complication. |
#7
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Commercially Available Valve Stem Mounted Puncture Alarm
Or - notice the bike is handling strangely.
Do a video of a cyclist detecting a 20 kPa drop in pressure w/o a pressure transducer. You can post the link to this thread! |
#8
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Commercially Available Valve Stem Mounted Puncture Alarm
https://www.dcrainmaker.com/2018/04/...re-sensor.html
It's assumed the cyclist pretty much knows what the pressure is at the beginning of a ride, and, if no punctures, that shouldn't be much more than 40 kPA different than at the end of the day. So the only interesting event that needs to be monitored is a rapid pressure drop indicating a puncture. What cyclists really need is real time ( 3 seconds) smoke detector like piezoelectric shriek when the pressure drops, say, 20 kPa over 3 seconds. It's only necessary to determine the time rate of change in pressure to alert the cyclist he has just run over a thorn.Â* A button battery powered sensor that detects rapid changes in air pressure should be at least as cheap as one that monitors pressure itself. A fancier version could have 3 different pitches for 3 different leak rates, high for 40 kPa / 2 sec, medium for 20 kPa/3 sec and low for 7 kPa / 3 seconds. Then the cyclist has a clue as to how long it'll be before he's on the rims. Is anything like this commercially available?Â* On a production basis it shouldn't cost much more than a $5 smoke detector. Bret Cahill BMW cars (and other makes such as Toyota, Pontiac and Cadillac) do this.. Why not just buy a bike made by one (or more) of those? all recent cars must have tyre pressure monitoring, it is a legal requirement now. Many bicycles use car size valves, it is easy to buy a set of valve caps to fit car size valves that transmit the tyre pressure to a little monitor screen Why waste time looking at a screen when a piezoelectric shriek is faster, smaller, easier, cheaper, more durable and more reliable? Bret Cahill |
#9
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Commercially Available Valve Stem Mounted Puncture Alarm
On 03/11/2018 17:33, Bret Cahill wrote:
Or - notice the bike is handling strangely. Do a video of a cyclist detecting a 20 kPa drop in pressure w/o a pressure transducer. If the cyclist can't detect a pressure drop, it's not a pressure drop of any importance. |
#10
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Commercially Available Valve Stem Mounted Puncture Alarm
Or - notice the bike is handling strangely.
Do a video of a cyclist detecting a 20 kPa drop in pressure w/o a pressure transducer. If the cyclist can't detect a pressure drop, it's not a pressure drop of any importance. Unless it takes place over 3 seconds. Most cyclists like early warning. |
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