Mongoose Cx's!!! fun

[diggler]

Totally awesome man!
I'd recommend 15 or 18fet if you think you might want to get the most from bht. Also, I use infineon 18fet, and the motor is quiet enough- chain and freewheel make more noise imo. I went with #35chain. Also, simply reaming and welding a sprocket on the shaft has worked great for me so far. No quick changes tho :lol:

What kind of amps you think I could get away with at 96v to the motor? 60amp is probably plenty wouldn't you say?
Is this not 12fet territory or more like 15fet to be safe?

 

[nutnspecial]

Re above: Hmm, I'm not sure anyone has tried that. I also didn't realize 12 or 15 fet was rated for 60, or available in 100+ volts. I think my 18fet is rated 96v and 60a, but to be safe batt voltage should be below the 96v cap limit. She doesn't seem to strain it all sending about 80v x 70a to the bht though. I don't plan on ever going bigger on the controller for the little 11lb bht.

Re below: If you plan on that, consider 3kw is probably about all most people even think about putting through bike drivetrains. Bht is overkill for that for sure, and doesn't require anything other than a 219 or 35 single reduction to the rear. A parallel or stand alone drive.
If you want to do a serial drive (thru the cranks), consider a lighter smaller motor like the gng?

I plan on doin the #35 to a freewheel front crank to a 5 or 7 speed rear right side gearset. Though an internal gear changer would be better.
Do they use the planetary gear system for those internal gears? There only 3 speed right? I still would use over the standard.

Btw nice vids and documentations so far. Those bikes are awesome. I'm curious how you'll like the hub vs better than stock mid.

 

[diggler]

If you plan on that, consider 3kw is probably about all most people even think about putting through bike drivetrains.

So this is probably the biggest motor for the job.
http://www.sickbikeparts.com/catalog/product_info.php?cPath=26&products_id=224
Sais 1800-3000w, so rated higher than the bht but must be more realistic.
It is designed to run through the front crank to the ?speed rear.
5speed chains are a little bigger than 6-7 right?

 

[diggler]

Yep tried redownloading everything from grin. Drivers, set up, v1.31, v1.3, tried unplugging everything I'm at a loss.
[youtube]RHGH4jknfNk[/youtube]

 

[diggler]

Look at there 48v 1000w motor, sais a whapping 94% efficiency! Idk sounds like smoke and mirrors. But it is $200 before shipping. That efficiency would make up a bit for the extra losses going through the front freewheel.
http://www.sickbikeparts.com/catalog/product_info.php?cPath=26&products_id=170

 

[nutnspecial]

I'd have to look that up on the chain. Might would be same as 6/7 or single speed.
You're comparing alot of different motors for different situ's now. I can't lead you too far 'cept what I'm using.
Reduction, Kv, amperage, dimension, weight- all different. Actually those are surprising close in weight to bht, with much lower rpms, but it's gonna come down to what you're looking for.

Gng is selling theirs singularly now, and there's the 'alternative' alternative bigblock bzh listed about a page back in that thread.