Here’s some video of freewheel unicycling on hills. In the first part I try to ride down a short section without using the brake to see how fast I can go. My estimate is 8-9 MPH. In the second part I use the brake while descending the hills. I’m getting my 26" freewheel unicycle soon so I wanted to try to remember how the 20" behaved on these hills so I can compare.
Are you sure you are only going about 9mph? It looks quite a lot faster.
Good question! It definitely seems pretty fast to me and it’s possible I’m underestimating. I was basing it on a possibly faulty assumption. There’s a steep hill which has a radar speed measure:
My fastest recorded speed on that is 12MPH and based on how fast I had to run that out I’m going slower in my video. However, it’s possible that the radar is measuring me at a slower point than I achieved (it keeps going downhill) so perhaps I was going as fast as 15MPH meaning my video was more like 10-12MPH.
I’m trying to work up to (and find) hills that let me go faster for longer and that should give me a better measure of my actual speed. I don’t know if the bigger wheel size will make it easier or harder but the disc brake on my new unicycle will hopefully give me more confidence to go faster. On my current unicycle I’m using a caliper brake with a rim that’s not particularly true and is not designed for a brake and it’s a bit grabby.
Any suggestions on measuring speed? A bike computer probably would not survive very long. A GPS/phone in a good signal area might work OK over a longer distance.
Nice! You’re getting good at this! 
Thanks! It’s amazing what a little practice can accomplish.
Awesome! You’re doing great!!! What an inspiring riding and cool vid 
About the speed issue, you can use on your mobile phone the ‘Sport Tracker’ or any other app that do more of the same.
Keep Freewheeling…
Have fun,
UVcycle
Thanks! At this short a distance I don’t trust my phone to be very accurate, especially since I have to start and stop it. Over a longer distance it might be OK.