Building motorcycle suspension datalogger

Knowing how he suspension works on the track can be beneficial in reducing trial and error which often wastes precious track time.

For this, I built an Arduino-based datalogger using ultrasonic sensors.

First prototype was tested today with good success for front suspension, but suffered from inaccuracies and spikes at the rear [suspension] which I suspect due to the shape of the rear hugger (which was used for the reference point) scattering the ultrasound signal. I’ll try fixing this in the next iteration.

Initially I was worried that wind noise at high speed may be a problem. but I am happy to report that when tested today up to 250kph (GPS reading) the signal from the front suspension reading appears to have suffered very minimal / virtually no distortion.

Some items need fixing too:
1. sampling rate of 5Hz seems low. Need to try for 10Hz.
2. current system works by logging for 10 seconds before pausing for 1 second to write data to SD card. need to explore faster write or longer read time to reduce flatspots in the data.
3. obviously fix the rear suspension sensor.

if this works well, next step is to expand it to other areas, such as lean angle read and tyre temperature sensor/indicator/logger.

Test video of leisure stroll around the track, and some pics below.

The system

Mounted on the tank

Mounted on the tank

Mounted on the tank

Rear suspension reading by looking at how the rear wheel moves (not actual suspension reading, only,to simulate the behaviour)

Front suspension reading by looking at the front fender. The sensor movement is exactly the same as the suspension movement.