I need help about choosing what to assemble using various parts… it will be a frewheel, but what size?
I already own a cheap 20", a 29" disc Muni (just moved to 150 cranks from 125), a road Huni-rex (like a 29" always in high gear and with 125 cranks).
Now the parts I could mix:
A cheap 20" with a 25,4 seatpost (could reuse any part)
A 26" freewheel wheel
Nimbus Dbrake
Steel cheap modded seat
27,2 standard seatpost
27,2 completely flat saddle with handlebar
I tried to learn freewheeling on a 29", but it was difficult and hurting.
Does it makes sense if I build a 20" freewheel, and a 26" standard wheel mounted in a 36" frame Or should I use a 26"'wheel in a 36" frame (and learn FW on it?)?
Having ridden all three sizes you mentioned as a freewheel, I doubt your experiences will change much with a different wheelsize. Riding a freewheel simply is hard. I haven’t met anyone who learned to ride it, that wasnt either really good at using the brake already, or able to coast on a normal unicycle.
I’m not saing it will be impossible for you to learn, but it being difficult and hurting is to be expected. Freewheels are not as easy to dismount as normal unicycles, it’s common to land on your butt when instinctively trying to pedal backwards.
So a 20" freewheel means falling from a lower height… I’ve got too many things to learn in too many different unis. I’ll tear apart my 20" (I won’t miss it) and rebuild it as a freewheel!
I am wondering if the following setup would work for a freewheel:
A penguin unicycle with a small wheel. The freewheel mechanism could be placed, I suppose, between the cranks, rather than in the hub of the wheel. AFAIK, the main technical difficulty in freewheeling is the problem of keeping the wheel behind your center of gravity…and making adjustments (feathering the brake) when the unicycle gets out ahead of the rider. The penguin setup would have a fulcrum at the pedals/cranks, and by adjusting the relative position of the seat (with one or both hands on the seat or bar ends) and the crank-axle, the contact patch of the tire could be quickly be adjusted forward or backward relative to the rider’s center of gravity. The primary means of keeping balance while coasting would change from delicate braking with one arm and the other arm flailing…to small forward/backwards adjustments on the bar ends. The setup could also use a brake.
Maybe someone with more engineering background could explain why this hypothetical setup might or might not work.
What you are describing could easily work as a freewheel. Just use a bicycle wheel with a freewheel on the bottom, a pair of cranks attached to a bicycle bottom bracket, and a custom frame connecting those two plus a seat. As always, I doubt it will make freewheeling much harder or easier than just using an already available freewheel unicycle.
You can ride a regular freewheel without the brake, just like you described: moving the contact patch forward and backwards under your center of gravity. Which is exactly what you do when you coast on a normal unicycle, and very similar in difficulty. It’s hard, since it requires a lot of body tension and precise movements. I don’t think the Penguin unicycle you proposed will change that. (No one I know or I’ve seen prefers their hands on the seat for coasting by the way. You use the muscles around your hip instead.)
Picture of someone coasting on a 20" freewheel for without a brake for reference. Notice the bend hip, which is where the adjustments are made. Blacked out faces, because even though I’m friends with everyone in the picture, you should ask permission first, especially with the new laws in place nowadays.
A freewheel with a brake is like gliding, and again, very similar in difficulty (A whole lot easier than coasting or freewheeling without a brake.) Since braking (with your foot on the tire when gliding, or your finger on the brake) allows for a much larger range of balance adjustments than pushing the contact patch forward an backwards does. Your center of gravity stays behind the contact patch (almost) the whole time, and you adjust the amount of braking to “keep the body up”.
