Carbon Fiber Wheel Covers

[RBurke83]

Although it’s probably against the spirit of eco-modding I’ve gone down the expensive rabbit hole of full flat panel carbon fiber wheel covers for my Ioniq 6. My goal was to make something that rivals or exceeds the quality of the Lucid Sapphire EV’s carbon wheel covers. The outer/decorative layer is a camouflage woven pattern carbon/aramid blend with 4 layers of standard 3k weave behind it. I laid up 24”x24” panels on an old mirror and vacuum bagged them with an Amazon bedding bag and hand pump-which worked amazing by the way. After lots of thought on how to cut a perfect repeatable circle I finally made a circle jig for my dremel and epoxied the collar to the jig. I then cut out a circle using the jig on a piece of acrylic. I inserted a metal peg into the center with epoxy which the jig rotates around. My plan is to take this acrylic jig/circle and double side tape it to a carbon fiber panel and cut the carbon circle out. As far as attaching the cover to the wheel-I’ve decided on laminating in 5 pairs of aluminum wire loops which correspond to 5 of the standard I6 wheel spokes, then just double zip tie each loop pair behind the spoke. I’m going to use a 3/8” piece of foam rubber weather strip all the way around near the edge of the wheel, basically as a stand-off for aerodynamic and aesthetic purposes. I plan on cutting a small hole to access the air valve with a matching carbon cover which will rotate and close from the inside using a curved and thus pre-stressed carbon fiber ‘spring’. When it’s all finished I will post tuft test photos before and after.

Lemme know what ya’ll think and be honest I can handle some flaming!

[freebeard]

I don't think you should apologize for build quality. ROI is only one criteria.

I do wonder why all that effort doesn't include a convex form.

[RBurke83]

I’m pretty new at the composite game and I don’t think I have the knowledge or skills to vacuum bag a form that is anything other than 2D. It’s fairly easy to get CF to mold release from a glass surface but anything else requires mold casting and whatnot. I may experiment in the future with it though.

[Phase]

Here we go with the convex form which modern cfd says it’s not as good as flat covers and why automakers are using flat covers now. It’s also tire dependent. If you have flush aero tires then flat covers make more sense than a bubble looking tire from the 1960s

Air curtains and flat wheel covers work together

[aerohead]

Originally Posted by Phase

Here we go with the convex form which modern cfd says it’s not as good as flat covers and why automakers are using flat covers now. It’s also tire dependent. If you have flush aero tires then flat covers make more sense than a bubble looking tire from the 1960s

Air curtains and flat wheel covers work together

If the tire has any sidewall camber, then the 'convexity' becomes an asset, and the flat cap a liability.
Case-specific application.

[j-c-c]

Originally Posted by RBurke83

Although it’s probably against the spirit of eco-modding I’ve gone down the expensive rabbit hole of full flat panel carbon fiber wheel covers for my Ioniq 6. My goal was to make something that rivals or exceeds the quality of the Lucid Sapphire EV’s carbon wheel covers. The outer/decorative layer is a camouflage woven pattern carbon/aramid blend with 4 layers of standard 3k weave behind it. I laid up 24”x24” panels on an old mirror and vacuum bagged them with an Amazon bedding bag and hand pump-which worked amazing by the way. After lots of thought on how to cut a perfect repeatable circle I finally made a circle jig for my dremel and epoxied the collar to the jig. I then cut out a circle using the jig on a piece of acrylic. I inserted a metal peg into the center with epoxy which the jig rotates around. My plan is to take this acrylic jig/circle and double side tape it to a carbon fiber panel and cut the carbon circle out. As far as attaching the cover to the wheel-I’ve decided on laminating in 5 pairs of aluminum wire loops which correspond to 5 of the standard I6 wheel spokes, then just double zip tie each loop pair behind the spoke. I’m going to use a 3/8” piece of foam rubber weather strip all the way around near the edge of the wheel, basically as a stand-off for aerodynamic and aesthetic purposes. I plan on cutting a small hole to access the air valve with a matching carbon cover which will rotate and close from the inside using a curved and thus pre-stressed carbon fiber ‘spring’. When it’s all finished I will post tuft test photos before and after.

Lemme know what ya’ll think and be honest I can handle some flaming!

So what thickness CF did you end up with?

[RBurke83]

When I get home tonight I’ll look for my digital calipers but tbh I haven’t seen them in a while so not sure I’ll have an exact answer but the feel test I’d say more than 1mm and less than 3mm.

[j-c-c]

For those on the sidelines, DIY CF layup does not require vacuum bagging. Is it a respected often sought after process, but can sometimes be mimicked by simply clamping or using weight to achieve nearly the same goals, slightly less weight and better epoxy to CF ratios in the finished item. My comment here is to not let vacuum bagging be an impediment to choosing CF as a material solution.

[j-c-c]

Originally Posted by Phase

Here we go with the convex form which modern cfd says it’s not as good as flat covers and why automakers are using flat covers now. It’s also tire dependent. If you have flush aero tires then flat covers make more sense than a bubble looking tire from the 1960s

Air curtains and flat wheel covers work together

Almost any form vs perfectively flat will increase the items rigidity. That extra rigidity will reduce any likelihood of flutter which aero wise will be a negative. Or the items thickness/weight could also be the solution to head off flutter. I think a rotating unsprung wheel at speed on a typical road surface would-be a favorable 'situation to help initiate possible flutter in these situations.

[RBurke83]

I’m hoping that my foam rubber ring along the edge between the cover and the wheel will accomplish a few things, firstly raising the height of the cover from the wheel (bringing the cover surface in line with the aero lip of the Pirelli P-Zero tire. Secondly I’m hoping the ring will compress and introduce some tension into the cover to prevent flutter. A distant third *might* be braking heat dispersion-although I use mainly electronic braking so not much of a concern.

As far as vacuum bagging goes, I wanted a minimum of weight as the wheel will likely not be able to be balanced while the cover is attached. You can probably achieve a very similar result using a simple wet lay method, but vacuum bagging is more tolerant of too much epoxy/resin.