Carbon Fiber Wheel Covers

[j-c-c]

Hope springs eternal.
Realize the constant slight offset of any amount and/or any imbalance of the cover will only worsen over time/rotations the offset and will likely lead to CF cover's self-destruction and/or separation.

The lightweight aspect is in your favor.

But my concern here is say the shock loading of say hitting a pothole shifting the cover any amount and when driven at speed that imbalance will only increase as the cover moves more off center.

I would not drive the car at speed in this condition with your arm resting on the open windowsill.

[RBurke83]

Good point. Any ideas or potential solutions? As an exercise in being stubborn I do want to remain faithful to my original concept of completely flush with no visible hardware. I have some extra carbon panel cut offs, I don’t think it would be too difficult to epoxy in four tabs? on the back side, essentially location reference tabs. The tabs would protrude down the edge of the rim and just short enough not to touch the tire. This could also probably be accomplished with wire which would make them somewhat adjustable for snugness

[Piotrsko]

I believe the wire will produce localized high pressure stress fractures, a typical failure point for CF

[j-c-c]

The varying thickness of the large IMO glob of 5 min epoxy will IMO reduce localized loading of the CF by the wire clips. If the cover is truly centered and well balanced, the load will be rather minimal and therefore increasing the fatigue life of the CF.

[j-c-c]

Originally Posted by RBurke83

Good point. Any ideas or potential solutions? As an exercise in being stubborn I do want to remain faithful to my original concept of completely flush with no visible hardware. I have some extra carbon panel cut offs, I don’t think it would be too difficult to epoxy in four tabs? on the back side, essentially location reference tabs. The tabs would protrude down the edge of the rim and just short enough not to touch the tire. This could also probably be accomplished with wire which would make them somewhat adjustable for snugness

That would be a huge improvement in regard to my previous concern.

[RBurke83]

After JCC pointing out a fundamental flaw in my design I opted to go the wire route to center and stabilize the spinning cover. I did a dry run with the wire tabs taped to the cover to find the appropriate placement. As it turns out if the metal just peeks around the edge of the disc, from directly above, then the cover is pretty near perfectly centered. I bent the tabs inward a touch and if all goes well during the curing of the thickened epoxy the cover should literally snap onto the wheel.

The cover with all attachments,minus 5 zip ties and a 1.25” plastic snap in panel plug, weighs 455 grams.

[aerohead]

Originally Posted by RBurke83

Good point. Any ideas or potential solutions? As an exercise in being stubborn I do want to remain faithful to my original concept of completely flush with no visible hardware. I have some extra carbon panel cut offs, I don’t think it would be too difficult to epoxy in four tabs? on the back side, essentially location reference tabs. The tabs would protrude down the edge of the rim and just short enough not to touch the tire. This could also probably be accomplished with wire which would make them somewhat adjustable for snugness

Local boneyards gave me damaged HONDA aero bits for nothing, and I destroyed them at home, to 'see' how they handled their hidden attachment points.
These parts appeared to be manufactured by rotational molding inside split molds. Evidently, Grade-8, hollow, 10mm, female-threaded inserts, with 'knurled' exteriors, were registered in the tooling, then captured by the thermoplastic.
The inserts were so 'stable', and 'fixed', that it took 'destruction' to get them to 'fail.'
I like the idea of the epoxy 'globs' a lot. Engineers used to design structural part prototypes from clear acrylic. Under 'strain and stress', the parts, under a specific coherent light source, would demonstrate Newton lines of interference at planar intersection reinforcing gussets, webs, and such; which informed the engineers about stress concentrations which would ultimately lead to failure in service.
If you study the inside of bulkheads, engine blocks, pistons, etc., you can see how selected radiused 'thickenings' were chosen to distribute point loads over a larger area of real estate.
Having a CF 'discus' flying at your elbow would be a real buzz-kill.

[RBurke83]

I put the front drivers disc on and did a quick and dirty tuft test. The smooth cover showed noticeably less disruption then the stock 20”. I was actually a little surprised at how badly the stock wheels looked on video. I will be taking this off and doing some finishing work. Also I’m less confident with the zip tie technique, something about it makes me nervous ��*♂️

I apologize for the images I was holding a selfi stick with my phone out the window….

[j-c-c]

I'd say you hit a home run.
Never would have guessed that much increased aero calmness.
Even see some before the wheel.
Listen to your gut on the zip ties.
Since everything in engineering/design has a potential downside, might want to make this small investment to keep track of brake/wheel temps.

https://shop.wilwood.com/products/temperature-strips

[Vekke]

Those carbon covers should boost your range 5% with +-1% tolerance based on my experience.

Cooling holes are quite big and if size is 20"...