Quote:
Originally Posted by arcosine
Its exactly the opposite of what you describe. A long nose coupled with a lot of trial is not good. Maybe Matt Weaver never rode in gusty 20 mph cross winds, but I can tell you from experience that the side forces are coupled directly into the steering and the more trail, the more torque has to be input to the steering to correct. The smallest nose in the front is best for side wind stability. I once tried 12 inches of trail, and when I put the fairing on it was almost unridable. The wind pushes and trail turns the steering away from the wind, not into it. Negative trail would do what you are saying.
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I went with a short nose for this vary reason. My first coroplast design had a nose that only went 932mm fore of the front axle line and the tail tapered back fully. This proved to be very stable even when the wind was gusting at 40 mph in Corpus Christi, TX. The 39" front track also helped, and the camber allows car-like levels of G-forces during turns.
My next coroplast design has a slightly longer nose, the tip now being 990mm in fore of the front axle line. From the top down view this new shell approximates perfectly a NACA0020 airfoil with a 600mm width. From the side view, it is a NACA0020 with a 630mm width. Both have the same focal point relative to the axle line, however the 630mm width NACA0020 side profile is beveled/flat at very the front, but otherwise staying true to form. This is about as close to a perfect teardrop as I will be able to get with flat coroplast pieces while keeping the design simple(the front cross section is 6-sided, keeping the number of pieces down and allowing easy/fast construction).
The goal is under 300W to do 30 mph, while retaining open wheels, which should make it come close to a commercial velomobile like a Mango, Strada, or a Quest.
It won't be no Milan SL, but once I put a motor in it, it will be the most energy efficient highway-capable vehicle around for hundreds of miles of radius by a wide margin, and able to be operated purely under pedal power if desired, as well as useful for committing random acts of jackassery; activities like drag racing cars, disturbing shopping malls, and doing donuts in a church parking lot while blaring Dimmu Borgir's "The Sacrilegious Scorn" or Ghost's "Year Zero" could be all kinds of fun. AND it will be carried into a home or an apartment building for quick hiding if need be(don't worry, I'm half joking here...).
They call BMW "the ultimate driving machine" in the commercials, but what I'm after is "the ultimate hooning machine". It doesn't get any lighter than a human powered vehicle as a basis point. Beef everything up for reliability and put as much power as can be fit and it will be interesting to see what happens.