In this scheme the direction of the wheel rotation is opposite to the direction of the pedal rotation. This is why we like to see sketches of proposed designs.
He’d also have a very unique cycle, and the pride that comes from his own innovation.
Dang, people, can’t a kid build a custom unicycle with his dad? I didn’t see anywhere that he expects it to replace sliced bread as the next-best-thing; sheesh, he’s just a kid! I did the same thing when I was 18, and I’m glad I didn’t have this group to discourage me before I’d even started.
If it works, great. If it doesn’t work, maybe he needs to try again. In either case he learns something. If he wants to share his design, people who know what they’re talking about can offer helpful suggestions.
For Borgschulze, I have ridden something a little bit like your drawing. It was simpler, with a simple pair of gears to transfer power from the cranks into the axle, making for a “standard” two-wheeler (reverse drive). Though it worked, you could feel a percentage of the input energy being sucked up by the gears. I think on a design like yours you’d have to allow for an even larger percentage of energy loss through the drive system. But, that’s one of those things you never know until you build it. And even then you don’t know because maybe you can improve what you built. So don’t discourage people from trying. 
See what I built here; a simple chain and sprocket upgrade.
Oops.
Cool. That does it.
I don’t think he is trying to make something on par with what you can buy, building things is fun and when you’re done you have something to play around on.
Looking forward to seeing it completed, good luck!
so close to finishing the wheel im using a 26er with most of the insides taken out i still need to take it to my dads shop to use the drill press to hook up the cranks. THIS REALLY IS GOING TO BE BUILT
the gears will be interchangeable
sounds good man hope it all works out and have fun building it, I used to build lots of stuff with my dad and it was great fun
just figured out the gearing ratio. it will have a 2.315789/1 ratio and with the 26 inch tire it will ride like if it had an about 60in wheel diameter
Don’t die riding it please.
That’s a pretty tall gear. I have a 36er geared up to 54, and I think that’s a little taller than I’d prefer.
at least not until you get a verifiable speed record.
The feel of a 60" wheel? Dude!
Sounds like a great idea for a project. Inspiring me to build a giraffe.
This sounds brilliant, when do we get pics?
when its done it may take a while
actually here is how far i am now
Interesting.
Got it. You’ve got a bicycle freewheel hub that you’re using for your jack shaft arrangement, The bicycle chain ring and crank provide the drive and the shaft they are attached to rotates through the freewheel. You will have an up/down chain set to a double cog mounted on the frame somewhere. The down chain drives the cog that appears to be welded to the hub.
looking good