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?