Yes, we have dws ORIGINALLY POSTING
Dances with Shrapnel said:
Using your more common units of coefficient, reducing the coefficienct from say 4.0 to 3.5 yields a 12.5% reduction in drag.
and its now been amended to - something less confused.... ?
Dances with Shrapnel said:
Using your more common units of coefficient, reducing the coefficienct from say .40 to .35 yields a 12.5% reduction in drag. Phil Irving presented a coeeficient of 0.0008 and I arbitrarily picked 0.0007 (net 0.0001) which yields the same percentage reduction. I have a hunch Irving may have combined a few terms; don't know for sure without digging into an old fluid dynamics text and studying it a bit.
So design or redesign a complete bike for 2" lower and maybe 5-8% reduction in drag or reduce the coefficient by 10-12 or more percentage points. It could be be as easy as adopting a different tuck in riding position or a modified tail piece.
Irving was pragmatic. Testing to measure results could/would be done on a flat out and read the tach.