I hope I have not irritated anyone with this title.  Allow me to explain.

 

I was a trials competitor many years ago (1972-1980) and had many good bikes, mainly Montesa.  I am also a metal fabricator and engineer.  I am also legally blind.  Because I can not longer drive, I get around on foot and that is a drag.  So, finding myself with two 1000 watt electric wheel motors, a pile of Lithium batteries and some time on my hands, I thought to build some electric transportation.  Since much of my area is over rough patches (like going over RR tracks at non-crossing locals) and my eye sight being limited, I thought the best "bike" would be a trials type bike. 

 

I would like to build it as a rigid to simplify frame geometry.  So I wanted to ask this experienced group to give me some numbers that would normally be used on Classic Rigid trials bikes.  Like Wheelbase, fork angle, trail, etc.  I am building the frame from scratch using odd bits and some old race car tubing.  It will have 19 wheels (110/80 -19 tires) at both ends as it will be two wheel drive. 

I know it sounds very strange and I am definitely not going to try to ride any events.  I just want to have a reliable method to get around and kind-of re-live the days of plonking through the woods.  I will never forget the water and mud I used to navigate with my old Cota 348.  It was a very special time. Thanks 

Hi, From memory steering head angles on twin shock trials bikes are around 26 deg +/- a few, dependent on make.

For geometry info checkout "Trials Australia twinshock forum, article "steer clear"

https://trials.com.au/forum/viewforum.php?f=16

 

I would recomend getting hold of an old bike and converting it, that way you get suspension (nicer on the bum), 

Anyway good luck, very interesting project. Let us know how it goes.

 

still trying,

Thanks for this link. It is just what I was looking for. You are right that it would be easier to convert a bike, but there are regulatory stipulations. I have to have this considered a "Mobility Vehicle" and thus it must be electric and conform to certain dimensions. It will end up being about the size of a mini bike with a very short wheelbase. Still haven't gotten the regulatory dimensions. Ive built a mobility trike/ chopper before that worked well, but was a bit too wide. I'll have a sprung seat for the bums sake. The information you gave will make it easy for me to get started. Thanks