What’s the pros vs cons between the 2? Which do you prefer?
depends on which zipp disc and which bike it is going on.
aerodynamically it doesn’t make much difference one way or another.
one pro of the 808+cover is you can take the cover off for road races, kona etc
the zipp discs are probably lighter
zipp 900 for the disc on a p2
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808 with a cover might be faster on the p2, and will handle more like a normal wheel:
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looking at the chart you really have to decide if you are mostly riding at high yaw or low yaw. At low yaw Sub 9 is a better choice and in some conditions by a lot. High yaw I’d go covered 808 but if your’re not going to use the 808 uncovered then save the money and just buy a cheap al rimmed wheel and cover it for the windy days.
I don’t get the “a cover is as good as a disc” comments given this chart. For cheap wheels the cover is pretty poor compared to a disc, up until very high yaws. About 40 grams slower on ave below 10 degrees.
I also wonder why they only chose 4 wheels if they were going to the tunnel. I’d love to see more.
Reading this chart, it does say pretty clearly that the number one choice for speed is, a 808 cover. and if you cant go that way, the second best choice would be a sub 9. That is inline with my in field mesurement.
On top of that, the 808+ cover is more comfortable and better handling in corner than the sub 9. Pretty easy choice to me as to what is the best wheel option out there.
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Agreed if your race isn’t between 5-10 degrees of yaw. And that isn’t really unusual, but the number of time you know that vs the cost of having multiple expensive wheels for all conditions is pretty prohibitive.
Over all if someone wants or has a 808 I can’t see a reason to buy a disk vs a cover. I’m not sure I could justify telling someone that a low profile rim with a cover is just as good as a disc based on this. Its still a great low cost option though.
it should be noted that this test was done with the plastic bolts installing the cover, not the electrical tape method…which seems like it would be a wee bit faster, but who knows.
also the flat disc might edge ahead on some bikes like the p4/p3/shiv. its all very close, I wouldn’t really sweat it.
what’s a yaw?
i dont beleive that flat disc is faster ‘‘on some bikes’’ It happen that some bikes cant fit the bulge disc so better say it s faster with a flat disc if you are that company…
From what i have seen on p3 and p4… i would not give away the cover over a flat disc. Those are personal observations, i do not have a windtunnel in my backyard but in high cross wind at imc…p3 p4 etc… ride the cover or sub 9 over a flat disc.
i dont beleive that flat disc is faster ‘‘on some bikes’’ It happen that some bikes cant fit the bulge disc so better say it s faster with a flat disc if you are that company…
maybe, but ive heard of at least one person confirming that claim independently.
but very very small differences he said. might depend on what non flat wheel you compare it to im sure.
what’s a yaw?
the angle of the wind as it hits your bike and wheels.
From what i have seen on p3 and p4… i would not give away the cover over a flat disc. Those are personal observations, i do not have a windtunnel in my backyard but in high cross wind at imc…p3 p4 etc… ride the cover or sub 9 over a flat disc.
I have a similar dilemma as the OP. I have an 808FC front and used my trainer wheel + cover this year on my P3, but would like to upgrade for next year (IMC). Would buy a Sub9 clincher if it existed…
what’s a yaw?
the angle of the wind as it hits your bike and wheels.
Maybe this is a dumb question but how would a new triathlete determine that “yaw” stuff? I guess my question is, since there are different wheelsets that are ideal for different yaw conditions, how would i determine which set is best?
as a new triathlete you shouldn’t bother trying to split hairs like that. you don’t know what the wind will be like on race day so unless you have a huge quiver of wheels and supreme weather forecasting and do simulations based on the course map and guess about how trees and buildings will affect the wind speed vs weather station reported speed theeeen
so you can’t really know what wheel will be best.
pretty much all of the good deep front wheels are tuned for the same mid range yaw angles anyway.
discs are good at all yaw angles
narrow is good at low yaw angles.
bla bla bla
so get a good deep front (zipp, hed), a disc rear, and put narrow tires on em.
Maybe this is a dumb question but how would a new triathlete determine that “yaw” stuff? I guess my question is, since there are different wheelsets that are ideal for different yaw conditions, how would i determine which set is best?
go to www.hedcycling.com. They have a yaw calculator; play around with it for a while.
go to www.hedcycling.com. They have a yaw calculator; play around with it for a while.
and then don’t forget there is no way to figure out what the wind speed will be at wheel level by looking at weather station winds =)
Right, but you can see based on an expected bike speed and various wind speeds what range of yaw angles you can expect. Since I have only 1 aero front wheel, I don’t use it for a specific day/conditions, but more to help decide which wheel to buy based on expected yaws.
thanks for all the input everyone!!!
I learned alot today
thanks for all the input everyone!!!
I learned alot today
You will learn one more thing today. Look at what you wrote above, and identify the non-word. 