Ok! Yeah! You are right. I wasn't looking as closely at his parameters, somehow I read "I want to go 7 and 1/8 miles". apologizes.
Humor me for a moment, but: Perhaps there are certain benefits to a brushed system. If it's a drag race, perhaps there would be no need for a controller, and you could simply use some insane mechanical switch to connect the batteries directly to the motor (if it's just a DC motor, as opposed to AC or BLDC. Is that ever done? Kind of absurd, I admit.
New to endless-sphere? Notice a lot of signatures recommending Ebike.ca? That's because it's the best place for a quality and manageable, (but still 'real'), first build. Justin is a solid supporter of electric bike development, and a good source of equipment.
My hat off a thousand times to the green people that effectively run this forum. The ES Mods are superb.