there are a number of variations. in layman’s terms, in order of durability, the crank connecting via a lateral screw (cottered), the axle tapering to a square which goes through a corresponding hole in the crank (cotterless), and a number of large grooves in the crank fitting into grooves on the end of the axle.
i’m sure people can explain in more detail and correct me where i’m probably wrong.
(i really don’t mean any offence by this)
so you’re making a uni from scratch. just some thoughts:
-grinding bearings (very hard)
-bending tubes (not too hard)
-machining splined hub and crank arms (very hard and very super hard on your lathe)
-creating a seat (probably difficult)
-you will have to buy a tire unless your mother works for goodyear or firestone and can loan you there manufacturing facilities for a day
-making a wheel hub/rim/spokes (well, i sure can’t do it)
you said youre new to unicycling, this won’t be your first uni will it? you can ride already, right?
i think (IMHO) you’re opening a pandora’s box which will consume MUCH more money and time than what you’re expecting it will. it will be much cheaper to buy a top of the line KH or bedford uni.
if your dad is an engineer for trek bikes or shwin or something, then i humbly retract my statement, but your asking about how to connect cranks to frame so i’m thinking he’s not. but best of luck to you as i’m sure kris holm had to start somewhere too. maybe my next uni will be a “theriault_honda” 20" trials uni.
Hey man im not offended at all you know your way around them. and like i said im new to them but i can ride though just looking for a cheap way and a different way to get one as i do have all the equipment to build it and all the rest of the stuff. but Im just doing re search first and its not worth it. so thanks guys.
Why not start out by making one part to supplement / replace what’s already on a unicycle? Try making your own handle… or a seat post… or a frame. These parts are fairly easy to produce, yet they’ll still take time and effort to design, produce, install and refine. You’ll get some idea of the effort that goes into each part that makes up a unicycle.
Another thing you can do is to modify existing parts… put some longer / shorter / more / less pins on your pedal… drill some holes in your frame / rim to reduce weight… shave / gouge your tire to experiment with different tread patterns.
Don’t get discouraged that you can’t build an entire unicycle right away. Maybe one day you will… but it’s best to start one small piece at a time