First, just so you have some idea what you're looking at building, then some questions.
R84 said:
Hi guys I'm a newbie in the ebike world,
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thunderstruck Ev the budget screamer kit 72 v brushed. 160amp continues and 400amp peek. This has the altrax SPM 72400 controller.
FWIW, you're talking about a motorcycle, not an ebike, at least as most people call them. Unless your'e doing something like me, and hauling around St Bernards and heavy cargo (sometimes at the same time) in city traffic.
Part of it is the weight, because between the motor and hte battery, it's probably going to weigh as much as my CrazyBike2, which is over 200lbs without anything on it. (see link in signature; it's a long semirecumbent cargo bike capable of pulling an automotive-style-hitch trailer full of dog or cargo or both).
It probably wont' weigh as much as my SB Cruiser trike, but you'll probably want to build it as a trike so you can have space for the giant battery.
100Ah at 72v is a very very large battery, for an ebike.
SB Cruiser has just a 40Ah "52v" battery on it right now, and that pack is heavy enough I have trouble lifting it out of the seatbox compartment it's in, and I can't carry it any distance (a few feet at best). If I put the full 120Ah (3 of those) in there, it'd almost fill up the seatbox compartment, which is over a foot tall, and over a foot front to back, and around 3 feet side to side (basically like a bench seat, as a box). See the SB Cruiser thread linked in my sig, near the end of the thread, for the present configuration showing that.
If it were a 72v system, otherwise the same, it would more than fill that whole box, and I don't knwo what it would weigh, but I'm pretty sure my biggest St Bernard, Yogi, would be lighter.
If you want to put 100Ah 72v on a bicycle frame, I think you might want a trailer, or a trike you can fill the cargo area up with.
If you do it with a motorcycle sized/shaped frame, replacing hte engine area with batteries, that's a different story.
Ok, so....all that said, you should look at this thread
https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302
and then copy the first posts's questions to a reply in your thread here, along with your answers to those questions.
That will help us help you figure out what you *really* need, and get you building and riding what you actually would enjoy riding.