Chopper geometry

[brentville]

So, it seems that the classic Chopper look is achieved a couple of different ways. Either a small front wheel like a 20" with a long more or less straight fork and a steeply angled steering tube. The seat is low and layed back over the rear wheel.

The other look seems to be a big 24" or 26" tire up front and a smaller one in the back. The steering tube has the standard angle and the forks are bent to give a lowered and stretched look.

My question is what is the geometry for these types of bikes. What is the head tube/steering tube angle supposed to be if you chop and change it. It seems at some point the front wheel will want to flop over rather than pivot. And if you go with a standard steering tube at what point is the fork angle too steep and too far out in front of the bike so that wheel will flop over instead of pivot?

What about the front to rear tire size ratio?

I hope this makes some sense to you guys. Thanks

 

[Firewalker]

WOW this is a hard topic and it can go in many different ways. The best one made commercially is the Nirve "Switch Blade"

a good model to build from if you are building one from scratch and man this bike rides very well!!!!!!

here is the one I'm making right now

big thing to keep in mind is the placement of the bottom bracket in relation to the seat.....one of the biggest problems choppers have is comfort and peddle travel...

FW