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[springwhit]

I am brand new to the electric motorcycle world..  I am embarking on restoring a 1973 BSA.  I would like to be able to have a range of 40 - 50 miles @ 50 - 60 mph.  What size motor do I need? Batteries? controller? chain sprokets size?  Where can motors and controllers be purchased.  Any and all advice and knowledge regarding what i need to power the old beezer with eletricity would be welcomed.  I am not new to motorcycles, having ridden nearly 400,000 miles in all lower 48 stats over the past 40 years.  I just have this old BSA in my garage with a worn out motor and have been increasingly interested inwhat's going in electric world.  Thanks

[frodus]

lifepo4 for sure

an etek rt/perm or agni motor (or advanced DC series wound, D&D sepex or AC motor/controller)

any series wound motor controller (or sepex/ac if thats the motor type you use)

sprocket size depends on accel you need, 5:1 to 6:1 ratio.

[springwhit]

I am still a little ignorant about hp versus volts.  Seems I need something around 75 volts?

[frodus]

hp is based on torque and RPM

torque = current
RPM = voltage

so for what you need 72V sounds like a good start (just a standard number used in lots of controllers, battery packs, BMS, chargers).

[mKlRivPwner]

Welcome!
I'm new to this world too, so I'll dispense what I learned over my first few weeks to you.

1)  Your battery and range estimates are grossly OVER-estimated.  If you are putting together a system you think will get you 50 miles, count on only getting 35 on the road.  Look at some of the bikes that others are doing.  Find someone with the range you want, and ask them what batery set-up they use and what kW-Hr they have (if they can tell you).
2)  Your cost is an UNDER-estimate.  Sure you priced the motor, controller, charger, even the batteries and sprocket.  But did you count on screwing something up?  Did you count on the fabrication materials for the mounts and brackets?
3)  Having said all that.  You can do it.  Easier than you think having heard/read all that.

There's a couple of car guy idioms you probably need to be overtly aware of:

Guy one: "I just finished a weekend project."
Guy two: "How did it go?"
Guy one: "Well, I spent twice what I thought and it's took 3 months."
Guy two: "Not bad at all."

The Mechanics Triangle:
   Reliable
     /   \
    /     \
Fast---Cheap

Reliable + Fast == Not Cheap
Fast + Cheap == Not Reliable
Cheap + Reliable == Not Fast

This last one is the most important:
Make a plan and stick to it. (I know it's cheesy)
Many street rodders don't have a plan.  So when a fad comes around, they get sucked in and try to do it on their own car.  Or they change their plan simply because they want to do SOMETHING and can't do what they want at that moment.  By the time they finish, not only do they have different elements that don't mesh (a retro deck lid and an industrial hood), but a new fad has started.  Now they tear out half the work they just finished so they can try to get the new design into their car.  And before long, the guy across the street has a clean and running rod, while you're stuck with a bondo covered mess and you haven't even taken it around the block in two years.

I hope I didn't put a big downer on your plans.  That's not my goal.  I'm just trying to say: Don't get discouraged if it doesn't happen right away.  It will.  And if you don't hurry off and "settle" on a lesser product because you can't find what you want, you'll be very pleased with the result.

[frodus]

I've seen several rides get 50 miles or so, it requires lithium and quite a bit of it

so its not going to be cheap..... but its doable.

you'll need more than 5kwh as a starting point.