what do the numbers say about a disc rear ( CH aero-cover ) and a 30 mm section low spoke front ( ksyrium-like ) . . .
vs . . . .
a front and rear deeper section ( 404 ) combo ?
say for reference purposes, minutes over 40K at 25 mph. thanx mucho.
Well, if it’s 40K and 25 mph… then there’s no time difference! ;^)
Okay, really, I have no idea. Basically you’re asking if the difference in the rear wheels makes up for the difference in the front, right? Why not just go with the rear disk and the front 404?
A disc is the fastest rear wheel and it doesn’t matter if it’s a cover or a wheel. A disc is still a disc.
As a general rule of thumb, the deeper the dish in the front the faster it usually is. Spoke count/shape also plays a part but is not as significant as the dish. But also realize that a really deep front dish like a Hed Deep 90 for example can be a bit of a handful in windy conditions.
very astute obsevation, on that 40K 25 mph thing, brider ! 
no, i am just lookin for the data on those combinations. CH cover rear with 30 mm low spoke front vs deep section front/rear. i know this stuff is out there someplace, just dunno where, exactly.
Analytical Cycling? (Or whatever that sire name is)
I’m going to guess that the deep section front/rear will be a few (15ish?) seconds faster over the hour it’ll take to complete the course. Only because aeroness of the front wheel is more important than the rear.
ot
a - ha
a quick trip to analytic cycling reveals a 30 mm lo-spoke front/disc rear will give up 37 seconds to a 404 combo on a 40 K tt. interestingly, that number actually changes slightly on the website when re-entered different times.
anyway, seeing as a CH aero-cover costs 60 bones, and most bikes these days already have 30 mm lo-spoke count wheels ( free) . . . . . and 404’s cost well over 1000 bux more. . . . .
i am wondering as to the tremendous number of 404 sets a guys sees, as opposed to a simple stock front wheel with rear disc (cover).
there must be a lot of guys out there frustrated with losing tri after tri by 30 seconds !! holy disposable income, who knew !!! ???