If you fat bike, you talk about tire pressure. The goal for many is to run as low a pressure as possible. I was curious just how much it differed at various pressures.

So with that, an Intel Edison and Flex sensor were used to look at PSI.

Step 1: Parts

I used the following parts:

Intel Edison Inventors Kit https://learn.sparkfun.com/tutorials/sparkfun-inv...

Flex Sensor: https://www.sparkfun.com/products/8606

Step 2: Connect

Wire up the flex sensor to A0 reading the postive leg, and + - to the flex sensor, with a resitor on the negative line.

Step 3: Install

The flex sensor was stuck to the inside of a Maxxis Minion FBF 4.8" tire on an 82mm DT Swiss rim.

Step 4: Code

I used this code to read the ADC: https://github.com/humberto-garza/SparkFunEdisonAD...

I modified it to record the readings and take PSI as an input which is just used to make the filename. It is attached as tireTest.py . The results are stored in a CSV.

I graphed them in excel, manual I know, but I don't plan on repeating this much.

Step 5: Results

So what is the most interesting here too me, the tire gets the most flex at 6 PSI! Not 4 like I would have assumed, and as you would assume it is the most round at 10 PSI. I would have assumed 4 was the most flat, but interestingly while 4 PSI does not provide the widest footprint it does react the most. By that I mean the profile of the tire changes the most at 4 PSI.

By no means is this groundbreaking research, but anytime you make a widget it is fun!