Speed costs money, how fast do you want to go?
You can buy a sad old motorcycle. Rip out and sell the engine, exhaust etc and recover some money and end up with rusty old steel frame for free or close to it.
Buy an old golf cart, pull out the motor, controller and second hand batteries. Sell off the unused bits and end up with most of what you need for not much.
Put the lot in with the batteries sticking out where they will. Stick weld it all together with some scrap iron.
Presto! You've got a bike that will probably do 35 mph for 10 miles. Such a deep cycle on the batteries will destroy them in short order (they were old anyway) and then you can cut all the brackets off, put new ones on for the new batteries you've bought and instal them.
Then you'll have an old bike that will do 35 mph for 12 miles.
Then you realise that even with new batteries you can't go as far as you need, the bike weighs a tonne and is so badly balanced that you can barely ride it and stopping is frightening.
Then you remove the batteries and cut the brackets off again and fabricate new ones for lithiums. You should be able to sell off the lead and lead charger you don't need anymore at a small loss to someone else on this list who thinks lead will work.
Then you buy a BMS, controller, charger and motor to suit the lithiums and discover that the brakes aren't up to the new speed you can get out of it. So you pull them apart and find that you can't get spares for the old brakes. So you buy newer things that don't fit properly and spend a bomb getting adaptors made to mate them on. Finally it's together and it looks dreadful, so you buy fairings, fabricate mounts, cut holes in them and get them sprayed.
If you read the blogs of people doing that (building cheap electrics) you see that story repeated again and again.
Here's a typical story:
http://blog.evfr.net/?paged=14It starts in August 2007 and ends with the death of the constructor while out testing the bike (still incomplete) almost exactly 3 years later. Along the way are two old motorcycles, four battery packs (two never fitted to the bike), I think four motor mounts, two controllers, two motors, assorted chargers to suit the various battery packs, fork rebuilds, replacement fairing parts, resprays and repairs and seemingly endless hassles with registration insurance and title. I don't know how much time he put into it but if you value your time at more than 10 dollars an hour (I do...) then there's got to be 10000 dollars right there.
He clearly had fun, met a lot of people, learnt a lot. However at the end of the day he still didn't have a finished motorcycle he could ride.
If you like making stuff, go ahead, make stuff. Just don't imagine that you're going to do it for 1000 dollars and end up with something that you can ride with safety and enjoy.
Me, if I couldn't buy a ready made one I would buy a bran new top shelf motorcycle as a donor. I think a new Hayabusa would be good, they have a large heavy engine and probably the lowest drag of any mass produced motorcycle on earth. Their engines are popular with kit car builders so I could probably sell it easily. I'd put in about a 20-30 hp motor (Dual Agni 95R probably). A zilla or similar controller. And as many A123 batteries as I could jam in there to get the maximum discharge as close as I can get to 1C for better battery life.
Thank goodness I don't have to do that. Not that I have 40k kicking around looking for something to do anyway.
=:)
PS 14000 is the price of a Zero DS here in Australia. The government adds about 4000 in tax. There are no other makes available, Zero S or DS are my only choices for ready made. (unless I buy someone's homebuilt monstrosity)
PPS, the Zero won't do what you said you wanted, 30 minutes at 70 mph. By definition you're going to have to have enough batteries to limit the discharge to 2C. 70 mph is going to draw about 6 kW from something as slippery as a 'busa if you lie flat on the tank. Say 8 kW if you sit upright. So you will need at least 4 kWh of *usable* battery.
Lead shouldn't be discharged more than 50% (even "deep cycle" batteries). So you will need 8 kWh of lead. Lithium shouldn't be used more than 80%, so you'd need about 5 kWh of lithium.
You'd get about 7 Wh out of each small A123 battery. They're a bit less than 100g each, but say 100g with connectors. That's about 720 cells or 72 kg or 3600 dollars and you'd get about 1-2000 cycles out of them. So 1.80-3.60 dollars per cycle.
With lead you'd need 8 kWh. I'd go for the genesis 26 ah battery. They're about 175 dollars each and have about 300 wh. So you'd need 26 of them at 10 kg each that's 260 kg and $4550 and you'll get about 500 cycles out of them. So that's about 9 dollars per cycle. Of course with that much weight, your rolling resistance will go up, so you'd probably need to add about 10% to those figures.
