Thanks, Rookster,
I wrote out a better reply but unfortunately board software decided to eat it. I'll try again, never as good a second time of course but just as long.
The designs of a full fairing, short flat bars, breadloaf tank and seat hump first appeared back in the very early 60's or before. You'll notice my reply said, "On the genuine race bikes the reason for the seat and hump form is aerodynamics. The air is supposed to be forced up and over the high pressure area of the fairing, across helmet top, down the back in that low pressure area, across the buns and over seat hump. As it flows over seat hump there's relative high pressure just above the envelope rider is in. Air flows off seat hump and curls around downward and back forward in a C shape because of high pressure flowing over just above it and thereby pushes on rear of motorcycle which is in a relative low pressure zone.
This high pressure push into the rear low pressure area and bike's rear give a slight aerodynamic advantage."
This was the reasoning for doing it back then, so that statement is quite true. As stated, it was 'supposed to be'. Much has been learned since then. Wind tunnel testing was extremely expensive back in the very early 60's. For the most part only large aircraft companies had the money or facilities to carry out such research. It wasn't cost effective or even possible for a small motorcycle mfgr. on a desperate budget to do that for the sake of a single model that might sell in the few thousands or run one or a handful of races? So, most design work was done in the mind and on paper with some supporting longhand calculations and a whole bunch of good intentions. The riders proved or disproved out on the track.
You'll notice that pictures 1, 2 & 5 intending to show me mistaken all show a rider in an upright position, contrary to a rider in a crouch that I referenced. Other pictures 3 and 4 with a crouching rider seem to support what I had stated though it's unimportant. All those pictures are computer simulations where data causing a desired picture and intended result is entered and the picture is made by computer in the pixtels that were encoded. That's a bit different from a wind tunnel.
Unfortunately the text provided doesn't give details of Dr. Kamm's work though it mentions him. He did much to change prevailing thoughts on low speed aerodynamics and was a real pioneer. It's mostly thanks to him that we see spoilers on just about anything with wheels for the last 40+ years! The results of his research do support some or even most of what I described but the short mentions posted don't describe any of that.
Don't know how much of his work is available on the net but if it's there it's well worth the effort to track down 'Kamm Theory Spoiler' or 'Kamm theory aerodynamics' etc. for those interested in low speed aerodynamics, even fascinating.
In his cutting edge research he found that previously 'undesireable' eddies and turbulence behind a moving shape could be made to work positively, to actually push instead of create a low pressure drag or disrupted airflow, revolutionary to us at the time! Still, those were things of a different space in time, now long gone forever.
Remember please, we didn't have computers or megapixel simulations back then and even a hand held calculator was cutting edge technology for our pencil and paper draftboards, longhand calculations and head scratching.
Other examples would be the megaphone exhausts that appeared on those 4 stroke race bikes for a time. Of course we copied them as soon as they were seen. We and the designers thought they were maybe the absolute best answer yet, maybe: that the continually expanding shape would allows gases to exhaust effortlessly with zero back pressure and actually be extracted by the moving bike and low pressure behind it, what a concept! Since then large advances in research have proven much better designs that actually physically extract the exhaust pulses through wave reversion. However that's after the fact so it didn't stop anybody at the time, way back when and it was really fun trying.
I still very much appreciate young men attempting to give their own interpretation to some timeless designs from machines of days gone by and it's a lasting tribute to those many folks from long ago that became the legends of today.
The main event is to to always know what direction you're headed in and to do your best with a good heart and clean conscience to make the times you're in the most exciting times of all!
Stay with it, Ncstatecamp, you're doing just fine!
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