Hi Scott
You say I'll run in the 650cc A-BG class.
What kind of blower/turbo set-up do you have in mind ?
.. With an inline 4 tearing a wide hole in the air is my front tire even really going to make much of a difference?
Here's something to have fun and play around with
concerning frontal area/drag/HP
that I used for my little supercharged Indian:
Go to :
DRAG LOSS CALCULATOR ( and scroll down for 'calculator')
For calculating the frontal area I took a pic from the front
with markings for each 10 cm. ( This is what the bike looked like back then.
It's a bit different today )
...then made a 10 x 10 cm grit
( Arms tucked in more, on this pic )
...and calculated the area.
That came to 0.3355 sq. meter ----> 3.605 sq. feet.
As the parts further back from the grit-line appears smaller than they are,
so I adjusted it up to 3.9 sq. feet
I set the cd to 0.9, based on a know figure for another bike
and punched the figures into the drag loss calculator
Don't forget to ad to the
total weight of rider: helmet, leathers, boot, gloves
cd----------------------.9
frontal area-------------3.9 sq. ft.
weight------------------539 lbs.
speed-------------------
100 mph
Horsepower needed....:
24.9...............
cd----------------------.9
frontal area-------------3.9 sq. ft.
weight------------------539 lbs.
speed-------------------
120 mph
Horsepower needed....:
42.3Good luck with your bike !
