Would it be best to triangulate/reinforce ALL the joins? My biggest fear is the head stock coming away from the draw section at speed, and having a negative affect on my good-looks.
Also, on the subject of brakes, Shimano m-810 kits aren't that dear, have amazing reviews on performance, reliability, low maintenance and power, and a pair of floating 203mm discs (cryo treated, of course) should be fine? They don't look very "motor bike". Hydraulic scattered 4 pots.
Is there any advantage in increasing front caster? Helps self-centre, and adds a horizontal element to bound, effectively lessening the spring/shock rate, but decreasing the dynamic travel of the front shocks. How would this effect stability under braking? The Stealth looks to have a little more caster than this.
ie- road (motor) bikes have less caster than mx bikes.
Is it possible to have an adjustable seat? (not up/down, but fore/aft) 1/ A seat further back results in an "outstretched" riding position, advantageous at speed from a "frontal area" standpoint, (as your head would be lower) and weight rearwards helps stability (and up-rightedness) during DH riding, but 2/is terrible on long rides on your lower back. Also, if something bad happens, I lean back, and clench my knees together (gripping bike and increasing purchase on the pedals) and the wide part of the seat limits how far back you can shift your weight while you are awaiting impact, with your legs tightly held together. A simple "half scissor" with a retaining clip would be strong enough.
Battery position: I see some commercially available e-bikes with the pack vertically and aft of the seat pole. Minimum advantage is centre of gravity. Does lower CG improve balance at low speeds? Speed control could go under upper horizontal. It may also help protect the pack in the event of a wreck too, like into a tree on an angle I guess. Moving forward, the back of the bike is more likely to hit later and softer....
Also, the longer the frame, the less effect rider mass has on rider discomfort, enabling shock/spring rates to be decreased, further aiding comfort and safety. However this will increase frame stresses at torsion centres and joins, further contributing to the need for triangular reinforcement. 14kW is going to punish the rear wheel!!! Can you use a front motorbike rim to lace to the hub? tyres would be tougher!! Long rear trailing arm may help with weight transfer under heavy acceleration. I would certainly box/triangulate that rear arm too, up close to the tyre.
Also, are you designing around 26in, 28in, or 700c wheels?
I would really like to hear as many ideas as possible, so as to learn more stuff for when I start my custom bike.
Just if you are starting from scratch, the world is your oyster, and it would be nice to design something ourselves that's passively revolutionary, and ahead of it's time.
Royce Union D/S Mountain Bike, 500w Chituma front wheel kit
Stealth Bomber, custom electric kit....
NHW10 Prius - Ask, I may be able to help!!!