Will a wheelcover fit a Zipp Firecrest 808? And more important will the transition from the cover to the rim be as smooth as it was with an wheelcover on an old 404?
Looking at the profile of a firecrest rim I wonder if it fits good and will there be any aero benefit? Someone tried it already?
I’m interested in this as well. I am about to pull the trigger on a set of 808 Firecrest Carbon Clinchers.
bump, has any tried a wheel cover on a 404 or 808 firecrest?
I asked wheelbuilder and was told it would fit but I figure someone on slowtwitch has to have tried this already and can share your experience.
I think i read that at most yaw angles, the firecrest is faster than a disc.
I just got my wheelcover for my 404 firecrests and it fits fine
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IMO, a Firecrest with a wheel cover is a very bad ROI, unless you are going to Kona.
The wheel cover will transform any cheap rear wheel into a race-worthy disc wheel. Better or as good as a Firecrest rear wheel without the $1000 price hike.
$0.02:
My suggestion is a front Firecrest + a “normal” rear wheel and cover and Powertap. Same money, better to possibly much better performance.
My impression is that you don’t lose the aero benefits of the Firecrest or any bulged shaped wheel when you add a cover. So a covered 404 or 808 is faster than a training wheel covered. The “poor mans” Sub9 so to speak.
A covered 808 Firecrest could quite possibly be the fastest rear wheel ever made. (And what I will be on this season)
My impression is that Zipp (with the FC) changed the focus of their design to what happens at the rearward side of the rim. That’s where the air meets their *rim *first (as opposed to the front side of the wheel where the air meets the *tire *first). So by making the inside of the rim profile “big” they both created more side force there (less torque around the steering axis) and reduced the drag (by creating a pressure drop at the inside of the rim).
Add a cover and all that effort (of Zipps) is “wasted”. Then it becomes more a question of wake size. I don’t know, but my guess is that the FC rim shape can help the wake size coming off a 23mm tire but it can’t transform it to the wake size beind a narrow rim and a 19mm Bonty Aero Wing.
Anyway, I do believe the FC+cover is fast, I just don’t think it’s the best return of $'s.
That’s what I’m basing my suggestion on.
Could be for sure. Until someone runs some test we won’t really know. As long as we are running stuff through our heads, my brains say that while Zipp may indeed have cleaned up the leading edge interface, removing that interface entirely through the use of a cover is probably not a bad thing. Can’t argue with anything you said about wake size, other than I would think a full disc kinda calms everything down considerably.
not a bad roi if you do bike races a lot too!
IMO, a Firecrest with a wheel cover is a very bad ROI, unless you are going to Kona.
The wheel cover will transform any cheap rear wheel into a race-worthy disc wheel. Better or as good as a Firecrest rear wheel without the $1000 price hike.
$0.02:
My suggestion is a front Firecrest + a “normal” rear wheel and cover and Powertap. Same money, better to possibly much better performance.
Dave I think on some frames you might be right, but on ones with good rear wheel seat tube fairings the word on the street is flat discs are best.
My impression is that you don’t lose the aero benefits of the Firecrest or any bulged shaped wheel when you add a cover. So a covered 404 or 808 is faster than a training wheel covered. The “poor mans” Sub9 so to speak.
A covered 808 Firecrest could quite possibly be the fastest rear wheel ever made. (And what I will be on this season)
What!! Huh?!?! Am I falling behind? I am aware of Cervelo mentioning this, but no data and no independant verification. Am I wrong? Am I wrong?
(No you’re not wrong David, you’re just an *&^hole!)
The Super9, aka “Firecrest disc”, is wide and semi-flat and fits the '11 P4.
And “beats” the Z900.
I may or may not be aware of some 2nd hand info that may or may not confirm what Cervelo said.
I may also have heard that its a tiny difference one way or the other.
Really though I don’t know for sure but I’ve heard it from more than cervelo.
What!! Huh?!?! Am I falling behind? I am aware of Cervelo mentioning this, but no data and no independant verification. Am I wrong? Am I wrong?
(No you’re not wrong David, you’re just an *&^hole!)
… on ones with good rear wheel seat tube fairings the word on the street is flat discs are best.
You may want to check that again.
… on ones with good rear wheel seat tube fairings the word on the street is flat discs are best.
You may want to check that again.
I’d love to, you got some info for us?
Would a covered 808FC do a good impersonation of the Super9, do ya think? I think it may.
Looking at the wheel, I tend to believe that a disc cover would fit poorly IMHO as there may be a sharp(er) transition from rim to cover, and not smooth like the Sub 9 or HED bulge discs. I suppose that some careful trimming and bending could smooth the interface. I cannot see how it would fare better than a Super9, but who knows.
Thats interesting. Rappstar’s claim (includign the P3 in the list) would be in disagreement with Gerard’s claim and at least one tunnel test I have heard of.
If I win the mega lotto I’ll sort it all out for ya 
EDIT: no I think Rappstar is saying exactly the same thing I did