I am thinking about this for a while but I need some numbers so I can calculate something and stop the speculating.
I am thinking of havind a motor with a crank arm atached to the shock.
When the motor turns round the shock will be compressed and extended. I am thinking of measuring the voltage and amperage of the motor together with the motor data this gives me the force. And with a light switch on two points above and under the horizontal line to measure the elapsed time between a given distance gives me the speed.
I have done a rough calculation with the demands that I want to reach a shaft speed of 5m/s and a maximum force of 5000N with a chosen amplitude of 2inch to avoid the bottom out and top out bumper on a 3inch shock. But with these numbers I will need a 25kW motor. Wich is very much when I compare this to the dyno of
http://www.roehrigengineering.com/cart/product.php?productid=1&cat=3&page=1
they only need about 2kW. But they only get to a shaft speed of 0.318m/s and a maximum force of 5700N. But this is probably for a car shock.
So what is realistic for a bycicle for the shaft speed and maximum damping force?
I recall somebody saying the reached fork shaft speeds of 5m/s but with a leverage ratio of 2.5:1 this would be only 2m/s for the shaft speed of the damper. But then I still get 10kW required motor power.
I have also found this cheaper one,
http://www.shockdyno.com/howitworks.html
But here you excert a certain amount of power and measure the elapsed time. This wouldn't give you the regular dyno layout with Force on the y axis and speed on the x axis. I think this cheaper dyno is only to be used to verify wether a rebuild has been performed correctly or wether a shock is damaged or not working properly but it won't give a usable dyno read out would be my guess.
I hope you guys understand what I want to do and maybe somebody else has did it before so give me some advice.
I am thinking of havind a motor with a crank arm atached to the shock.
When the motor turns round the shock will be compressed and extended. I am thinking of measuring the voltage and amperage of the motor together with the motor data this gives me the force. And with a light switch on two points above and under the horizontal line to measure the elapsed time between a given distance gives me the speed.
I have done a rough calculation with the demands that I want to reach a shaft speed of 5m/s and a maximum force of 5000N with a chosen amplitude of 2inch to avoid the bottom out and top out bumper on a 3inch shock. But with these numbers I will need a 25kW motor. Wich is very much when I compare this to the dyno of
http://www.roehrigengineering.com/cart/product.php?productid=1&cat=3&page=1
they only need about 2kW. But they only get to a shaft speed of 0.318m/s and a maximum force of 5700N. But this is probably for a car shock.
So what is realistic for a bycicle for the shaft speed and maximum damping force?
I recall somebody saying the reached fork shaft speeds of 5m/s but with a leverage ratio of 2.5:1 this would be only 2m/s for the shaft speed of the damper. But then I still get 10kW required motor power.
I have also found this cheaper one,
http://www.shockdyno.com/howitworks.html
But here you excert a certain amount of power and measure the elapsed time. This wouldn't give you the regular dyno layout with Force on the y axis and speed on the x axis. I think this cheaper dyno is only to be used to verify wether a rebuild has been performed correctly or wether a shock is damaged or not working properly but it won't give a usable dyno read out would be my guess.
I hope you guys understand what I want to do and maybe somebody else has did it before so give me some advice.