Convex or flat wheel covers ?

[mcrews]

Originally Posted by Frank Lee

Solved!

CapAds not rotating wheel cover - No non not rotating advertising media hubcap

...and you can put big phat EM logos on there too.

Frank Lee,
How do you find this stuff!

[cfg83]

aerohead -

Originally Posted by aerohead

I don't think it's tradition.I believe the MOON cover to be superior. The crown adds hen'egg geodesic strength allowing a thinner/lighter gauge.
The crown also better respects Whitcomb's "area-rule" or the ballistician's "sectional density.
" The MOON cover doesn't add frontal area,as it is hiding behind the sidewall of the tire.
MOON's cover is actually thickest at the center,where strength is needed and polar moment the minimum.
MOON's are not inexpensive,and a flat home made unit might look attractive from price standpoint.
...

What do you think of these? :

Smoothie Hubcaps, Baby Moon or Moon Hubcaps Wheel Covers Kustom Car Moons

These are the classic smoothie hubcaps. Hubcap Mike's Smoothie wheelcovers have a beautiful polished finish ...they're like a round mirror. Also known as baby moon or moon hubcaps (baby moons), this smoothie is a chromed solid steel moon wheel cover with a 360° steel retention system which is a continuous part of the hub cap (all one piece). So when you put these on your wheel, they will stay put. These are very solid, all steel caps, not the cheap flimsy variety found elsewhere! Perfect finishing touch to a classic car restoration or kustom car project; your wheels will never look better!

At first they bow inward (which will help to clear the car wash tire grabber) and then they bow back outward. They are NOT racing disks, but they are close.

I don't know if these would fare any better than the snap-in racing disks. They have "the teeth", but the "tooth size" looks larger, and they have a hole for the valve stem, so you don't have to take them on and off to check your air.

As I was saying in another thread, I don't like chrome per se, but it makes sense that this retro-style of wheel cover would need to be chrome.

CarloSW2

[Christ]

Carlos -

If you don't like the Chrome, get some candy paint and scuff it up a little bit, then spray it on. You'll love the colored chrome effect!

[cfg83]

Christ -

Originally Posted by Christ

Carlos -

If you don't like the Chrome, get some candy paint and scuff it up a little bit, then spray it on. You'll love the colored chrome effect!

Een-tay-rest-ink! I did a graft to see what the unmodified moonies would look like :



I think I could get used to that if I knew the covers wouldn't pop off and I didn't have @#%(&@#%(*&#@$ alloys to begin with.

CarloSW2

[Christ]

That would be slick, my friend. Especially with a thin white wash over the chrome!

[Vekke]

My take on the matter
https://youtu.be/KvAwM4YqWRA?si=geJ9S9qNJv7gCwXK

[Phase]

Every modern car company is using flat covers or even CONCAVE covers. NO ONE is using the moon cap style

VW XL 1 cover is flat. Hyundai Ioniq hybrids and even their EV successors are flat with a few ventilation holes

Mercedes EQS is flat but slightly CONCAVE inwards.

The Mercedes EQXX- aka the best aero beast on the planet right now- flat covers with a very small concave shape in the middle going inwards

Light year one/zero solar car with .18 CD uses COMPLETELY FLAT fully closed wheel covers.

Literally not one car on the market that’s cd .21 or below and in the last half decade uses those moon cap shapes. The trend tends to be flat. I’ll trust the top aero engineers for low drag cars in the 21st century and all the good CFD software versus old wisdom.

[Vekke]

XL1 covers are not flat they are "convex" as you can see from my video shot at the vw dealer little while ago. They come out actually quite much.

https://www.youtube.com/watch?v=5Jp83gkrY_M&t=3s

There is other reasons than aero to manufacturers not use convex wheels. They get curb rash even more if spokes come outwards specially with those thin side profile tires. I have seen a study that concave vs flat wheels was about 1% penalty drag wise. Cannot find that study on my computer anymore though.

[Phase]

Originally Posted by Vekke

XL1 covers are not flat they are "convex" as you can see from my video shot at the vw dealer little while ago. They come out actually quite much.

There is other reasons than aero to manufacturers not use convex wheels. They get curb rash even more if spokes come outwards specially with those thin side profile tires. I have seen a study that concave vs flat wheels was about 1% penalty drag wise. Cannot find that study on my computer anymore though.

Well to be fair, that car is like a decade old so a lot of newer aero ideas hadn’t been used yet, like air curtains or extended diffusers. The xl1 wheels are more pizza pan shaped which I would say are a hybrid of convex and flat. Not building out and rounded like moon caps. They probably did it for stability and strength of the wheel and to align more with being straight with the body panels. I’m just saying the newer hyper efficient EVs are using more flat covers from this decade

[aerohead]

Originally Posted by Phase

Every modern car company is using flat covers or even CONCAVE covers. NO ONE is using the moon cap style

VW XL 1 cover is flat. Hyundai Ioniq hybrids and even their EV successors are flat with a few ventilation holes

Mercedes EQS is flat but slightly CONCAVE inwards.

The Mercedes EQXX- aka the best aero beast on the planet right now- flat covers with a very small concave shape in the middle going inwards

Light year one/zero solar car with .18 CD uses COMPLETELY FLAT fully closed wheel covers.

Literally not one car on the market that’s cd .21 or below and in the last half decade uses those moon cap shapes. The trend tends to be flat. I’ll trust the top aero engineers for low drag cars in the 21st century and all the good CFD software versus old wisdom.

When Volkswagen, Hyundai, Ford, Chevrolet, Oldsmobile, etc., took their 'halo' cars to the Bonneville Salt Flats for land speed record attempts, they ALL selected MOON wheel covers for these record book events.
--------------------------------------------------------------------------------------
Walter Korff, chief aerodynamicist for Lockheed Aircraft Corporation reported in 1963 that the slightly-convex, full-coverage ( MOON ) wheel cover was superior, aerodynamically.
--------------------------------------------------------------------------------------
Anyone who has access to Sighard Hoerner's, 'AERODYNAMIC DRAG', 1951, page-128, Figure 8.14, will see that this is true, and has been known to be true since the 1930s.
--------------------------------------------------------------------------------------
An argument germane to this topic, and of more value to ecomodders would be, the difference between wheels exposed within the wheel arches, and the same, but fully-skirted, which according to Ford Motor Company, quite recently, is what we ought to be interested in if we're really intersted in low drag, and not whether wheel covers are flat, or convex.
--------------------------------------------------------------------------------------
A 'commercial' argument against MOON-esque wheel covers might be found with those who currently manufacture, earn their livelihoods from, or own stock in:
ASA
Advanti DST
ALPHAequipt
ALUTEC
ANZIO
AVARUS
AXIS
BEYERN
Black Rhino
BORBET
Bremmer Kraft
DRAG
Enkei Performance
FLOW ONE
FLOW RACE SPEC
FORGED ONE
FOOSE
GRANITE Alloy
GRID
HELO
KMC
K'O'NIG
Liquidmetal
MAMBA
MB
METHOD RACE WHEELS
MHT
MIRO
moda
MONTE TITANO
MOTE G1
Mottino
MSW
O-Z
PLATINUM
RACELINE
SAVINI
Sparco
SPORT TUNING
SSR
TSW
ULTRA MOTORSPORTS
VERDE
VISION
V'O'XX
Walker Evans Racing
WORX
-------------------------------------------------------------------------------------
' If all cars were designed 100% aerodynamic, would they not all look alike, and the designer have nothing to do?'
H. Schmude, General Motors Corporation, 1963, SAE Congress.
--------------------------------------------------------------------------------------
' Follow the money.' ( 'Deep Throat', 1972 )