I plane old don't know! I looked at the power band of the 50cc Honda and felt that I Could "infuse" torque using my human power through the 8 speed hub along the speed range. It worked quite well... But I am quickly learning that this "electrical thing" is far more complicated!
It 's just different.
Regarding the riding requirements, I am starting with a frame set with excellent geometry for going fast over rough ground think 40MPH is "do-able". The "mechanics/ architecture" of the frame will provide an open platform for the "best of the best" motor and primary drive... However I really have no clue as to what that is!!! I read and read and read and just get mired in the technology!
First decide if you want to do this on a bicycle frame with bicycle components, which probably arent' cheap for stuff that will survive those speeds and condtions for very long, or move up to dirtbike stuff that might be more appropriate for those kinds of speeds and conditions.
Next, find out how much power it really takes to do what you want with the stuff you're using. (it'll take more power with a heavier bike, but the heavier bike can more easily carry the stuff to power it).
Which motor would be "best of the best" depends on what you choose to do, and how you want to do it. And on whether you mean "best quality", "best efficiency", "best design", best for the specific purpose, etc. And...whose opinion you listen to. :lol: (or how much money and time you have to buy things and test each one to find out whihc actually is best for your definition of that).
In all industrial design there should be a balance! I don't believe in putting 1000HP motors in commuter cars nor some crazy overkill motor on my bike, though I do want "higher end" performance from the bike (think of the Carrera's used in the Dakar rally).
The power requirement is "easy" to figure out; follow the suggestion farther down this post (also previously posted in the thread) for a starting guesstimate.
There are various ways to get "higher end performance", each of which has it's advantages and disadvantages.
I am very concerned about the over all width of the motor because I believe that there is a certain width between crank arms where pedaling is not good for you and should voided at all costs.
That's the Q factor, and that width depends on your body. There are a lot of articles, pages, and whatnot on the internet about Qfactor and how it is relevant to you and your ride choice; not all of them cover all the details, so reading multiple ones may give you a better idea about it. Here's the first useful hit on a google search for my first sentence of this paragraph:
Everything you want to know about the Q Factor that has some useful info. Sheldon Brown's website probably has good info too (almost anything you want to know about the mechanics of and/or repair of bicycles is probably on that website).
Good fit to keep from injuring yourself also depends on seat distance from the cranks vs your leg length and movement style, etc., and even distance from seat to handlebars, and bar height, etc. (that's why good frames usually come in multiple sizes; the cheap stuff that only comes in one size can't be fit to everyone, so anyone outside the range it was made for (if it was even made to fit *anyone* and not just made to have a certain look) will just have to live with what doesn't fit them.
Enough battery power to last a days ride.
To figure out if that's possible, and if so how much battery that will be:
How far is a days ride, worst case (longest distance)?
Under what specific riding conditions, on what terrain?
At what speed? Any winds?
You can use the simulator at ebikes.ca to use the above info to figure out how much power it takes to do that job, and then get a wh/mile guesstimate, then use that to figure out how many wh it takes to go as far as you need to go, which gives you an approximate minimum battery size.
"low-key" so it does not draw attention.
For that, it depends on where you ride, and what you're doing. If it's offroad in areas where it's allowed to ride, then it doesn't really matter, unless some vehicle or bike types are disallowed.
If it's onroad, then don't ride in a way that attracts attention and unless you just have picky leos you'll probably be left alone. I ride contraptions that most definitely attract attention (if people see me, they're less likely to accidentally run me over), but I ride safely and within the rules of the road, so nobody bothers me.
If you have a situation that requires a "stealth" bicycle ride, then you're probably going to need small everything so you can hide it behind other stuff (panniers, etc--stuff that you see on bicycles in your specific area...if your bike looks different than those in the area, then it'll attract attention from that reason alone.
But if you ride in a way that attracts attention, it doens't relaly matter what the bike looks like....
