The bike was run naked and streamlined in 2018. It went 129.02 and 149.63 without and with the tin. The sheet metal helps a lot. The wind tunnel guy said "Put on as much streamlining as you can before the testing. It is a lot quicker and easier to take it off than to put it on." This adding was done after the 149.63 run. Quite a bit of thin aluminum roof flashing, duck tape, and cardboard was used. The drag coefficient for the first test with all of this in place was 0.494 The smoke wand showed a lot of power robbing turbulence behind me. The second test was made with me holding my chest lower down onto the fuel tank. The drag coefficient dropped to 0.457
It was hard for me to hug the tank and I doubt if I could do it during a race. So, the seat pan was lowered a little more than an inch, the bum stop was moved back an inch, and the front of the seat pan was narrowed so it is easier to keep my knees against the tank. This I did last week.
My weight was between 210 and 220 pounds when my leathers were originally made. Now I weigh a lot less. The scrotum like folds of the excess cowhide caught the wind. Duck tape was used to tighten up the leathers during the tunnel work. The operator mummified me. The smooth leathers dropped the drag coefficient down from 0.457 to 0.445 Bates remeasuerd the new slimmer version of me and altered the leathers.
A speed hump was made on my leathers behind my head using more cardboard and duck tape. It raise the drag coefficient from 0.445 to 0.463 A speed hump does not work for me. The speed hump was removed.
The tail end was open during all of my racing including the 149.6 run. It was closed with roof flashing during the initial tunnel tests. The drag coefficient went up from 0.445 to 0.453 after the tail was opened. The tail was closed up with 0.020 thick sheet aluminum this week.
There are power robbing turbulence vortices behind the tail end. Closing the tail reduced the size of this turbulence, is my best guess. The next post will have pictures.