Some questions...

Wow! You'll be running with the big dogs!

For some perspective, have a look at:

http://www.austinev.org/evalbum/

4000W will eat a lot of amps, which means a lot of lead or short range.

It'll be fun, though.

MarkF

Yeah, I know. When the pack is finished it will probably consist of 8 batteries x 12V x35 AH = 3360 WHrs. They weigh about 25 lbs. apeice (according to my bathroom scale, which is off by I don't know how much) so that's going to be a 200 lbs. of battery. I'm hoping they will last at least 20 min. at flat out. Maybe more, since the amp rate will be only just above 1C.

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contained herein.

As far as gearing is going - a single sprocket is not out of the question (unless you want it to be for some other reason). Track down El Ninja by John Bidwell and numerous other motorcycle conversions. They often use a single fixed chain and sprocket. El Ninja uses a 16 tooth front and 72 tooth rear. On my CB-750 I'm considering 10, 11 or 12 front (TBD) and using the original 48 rear. This won't give blistering accel (!) but should be good for a top speed of 60+ mph. These bikes are considerably heavier than what you describe.

What are you aiming for? Do you favor accel over top end or vice versa?

For sure a transmission will help - after the CB-750 I'm considering a maxi-scooter conversion and I'll attempt to use the CVT from the original bike. Don't know if a CVT from a small gas scooter would help you or not.

50% capacity drop at 1C!? Peh. What about 1/2C? I probably won't run it much higher than that anyway.

Actually, I'd really like some nice acceleration and best possible top, so I'm going to go with the transmission, since as far as I can tell it would simply be a matter of disabling whatever mechanism makes it kick in a a certain RPM. Anyone wanna recommend a good one? I'm looking at that torque-a-verter thing...

I'm REALLY hoping I can grab me ahold of one of them eteks I've heard such good things about.

...

I think I'll sell that battery. I'm eager to see how those second-gen supercaps turn out in a couple of years (supposedly TWICE the capacity of LiPo, and, seeing how it IS a capacitor, likely an unbelievable discharge rate!).

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contained herein.

Thanks for that link.

Hmmm, 25AH @ 1C...

Yeah, I'm ditching that battery. Maybe I can sell it on eBay after lead prices go up further (curses) and make a profit...

I'm thinking an Alltrax would be well suited to an etek. Can anyone here attest to that?

P.S. Why does it keep going "[i]" everytime I try to make a capital "i"?

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contained herein.

Yes, Alltrax and brushed Etek is a common combination. You might also check out Perm 132 instead of Etek it offers a greater power output. Check out http://electricmotorsport.com for details - they sell some packages based around these components. Not suggesting you do or don't buy from them it's just a useful starting point.

Yeah, that i / I thing has got me before - but not all the time. It's weIrd...

Yeah, I knew about the PERM-132, but I could get nearly two Eteks for as much as that thing tends to sell for(which I had kinda half planned on anyway).

Interesting, but not for me. I want to use one of the higher rated controllers in case I ever decide to use a different motor.

The going rate for the Etek seems to be +/- $500. Incedentally, anyone know where to get one for cheap? If not I'll see what eBay has to offer.

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contained herein.

It's because you probably hit "ctrl-shift-i". Hit it again and the behavior goes away.

"we must be the change we wish to see in the world"