Originally Posted by gilleek2
Wondering whether it's justifiable to splash out on a disc for a possible 2nd tilt at ironman next year. On a flattish course (austria or roth are likely contenders) would there be an appreciable difference between the above 2 combinations given reasonably low winds. Obviously high crosswinds would require a rethink. To give some background i did 10:10 (5:26 bike with 808/1080 set) this year in Austria in my 1st effort but reckon i've potential to do 9:45/9:50.
Thanks in advance for any responses.
Here is drag vs yaw for the two (the 1080 is in the light blue, Zipp Sub 9 disk in green):
(BTW, go to http://www.hedcycling.com/aerodynamics.asp
for this awesome app).
So, very little difference at up to around 7.5 degrees, then 1080 is ahead until around 14, then disk takes over. So I guess it depends on the winds you will see.
Zipp's own data says 23 seconds over 40k (808/Sub-9 vs 1080/1080), giving you maybe 1.5-2 mins over 112 miles vs your 808/1080:
Not sure what you mean when you raise the issue of crosswinds requiring a rethink - a rear disk has little negative impact on handling in cross winds compared to the front wheel - may even give better handling.