The 808s. The deeper rim is more aerodynamic. While a little heavier, for most of the course it will save you wattage over the 404s.

The 404 cc pair is a better option. For a variety of reasons.

sweet thats what i was thinking. i have never been to kona so have no idea how strong the wind can get. you don't think the 808s will give me any issues if its a really windy day? or will it be best to play it safe with the 404s? i have never had a problem with 808s here in NZ it can get a little twitchy at times but nothing thats going to blow me of the road.

what are those reasons?

If you think there might be an issue with the wind then definately go with the 404s... wasting energy fighting the wind just isnt worth it. If your having to focus on fighting your bike then your already going slower and getting frustrated at the same time. i weight 130 so the wind kills me even when im running 404s at times.

The main reason is that the 404 cc is a faster system design than your 808 pre-fc tubulars.

Another reason is that the GP4000s is generally regarded as being the best all-around tire in combination with wide rims due to its aerodynamic properties, its low rolling resistance and its decent durability. Better if the tires are <200 miles if I am not mistaken.

Another reason is that the Vittoria tire is generally considered quite poor, aerodynamically. Its good crr value may or may not make up for that but I can't remember.

Another good reason is that I am assuming you can change a flat much faster on the 404s than on the 808s, were such a thing to happen at the most important race of your year (again, assuming).

i know its probably all in me head but the 808s do feel faster and the vittorias also feel a lot smoother/faster.
also don't have a problem with the tubular side of things and believe i can change a flat tubby faster than a clincher. (properly glued with a razor blade)

well what's the point in asking for input then?

I did kona twice with zipp 606s. one year it was very windy and got very sketchy, especially on the downhill after the turn around. wind was not important the second time. I weigh 135lbs and was riding a cervelo p3 carbon. hope this helps.

The 808s with those tires might be a little faster at low yaw, but Kona isn't super low yaw.

But perception is very misleading, especially with tires. The differences are so small between those setups it is probably impossible that you really feel it.

Given that the 404 setup is, at worst, exactly as fast for the Kona course, and easier to control, I would go with that.

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

"Firecrest 404s are the new 808s" ;-)

http://www.slowtwitch.com/...e_new_808s_2118.html

The 404 FCs are actually faster in the higher yaw angles you're likely to encounter during that race.

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http://bikeblather.blogspot.com/

You could probably argue that the two are a "tie" aerodynamically given how important the tire is to the system and how well the GP4000s does on the FC rim. The 404s will be less work to keep straight and, if you have a flat, much easier to deal with.

cheers thanks for your input looks like ill be using the 404s

Definitely the 404's for Kona. Or a 404 FC front and the 808 rear.

haha i would do that but i don't want a tubular on the rear and a clincher on the front.