Ideas for smooth wheel cover on spoked alloy wheel

[freebeard]

I knew a old motorcycle racer who said they center-drilled bolts.

Maybe thread the a center drilled 12mm [bolt] for button head Allen bolts?

[j-c-c]

It's an idea, but I would be very hesitant to drill/tap a common wheel stud on a 4 hole wheel. Besides weakening the stud, it leaves a horrible internal stress riser if one does not drill all the way thru, which I also would never suggest on a stock wheel stud. Now if using say an ARP 625 super expensive stud, just maybe.

[freebeard]

I'd heard long nut on the stud with a short 12mm bolt. I was suggesting a reducer.

[j-c-c]

Well, I agree, no aero cap requires 4 12mm fasteners. Just custom fabbing an item of the correct robust one piece materiel as a reducer would be involved. A screw in reducer would work, lock tite it in place, and its material would be much less demanding for the application. I guess the reducer could also be made with the need standoff and kill two birds at once. That would require a very deep socket to remove/tighten the wheel lug nuts.

[Ecky]

Originally Posted by CigaR007

Why go through all this trouble though ? The original insight wheels are the best compromise between aero, weight and reliability/durability.

I disagree. They're excellent wheels, no doubt. Possibly the lightest 14" wheels put on any production car from the factory. At 11lbs, they're featherweights, a full pound lighter than the extremely desirable Enkei wheels from the Civic HX, and they're aerodynamic to boot.

Having owned and driven an Insight for near a decade, with numerous different tires and wheels, even an extra 1lb is noticeable in the rotating assembly. Switching from summer to winter tires, where rolling resistance was similar but there was an extra pound in the tire itself, made a noticeable difference in the driving experience. Stock tires on 1lb heavier wheels was noticeable.

These wheels are possibly 4-5lbs lighter, and likely significantly stronger. Bare wheel to bare wheel, it's a 44% reduction in weight, and with like tires, a 22% weight reduction. 16-20lbs from the rotating assembly, in the place it counts most. I just need to figure out the aero aspect.

Originally Posted by j-c-c

K>I>S>S
that being said, use open long lug nuts, (forget the spike solution) they will leave unuse female threads you can crew into and decide whether to use 2 or 4 attaching bolts of same thread as the lug nuts, if say 12mm, center drill them to reduce weight, you will need something to back stop the cover so the cap fasteners can be tighten against something. Might want to safety wire say two opposite bolts to see if the other two tend to loosen in extended use. I feel leaving a 1/4"? gap between the outer rim and the cap would be best for longevity of the wheel system in OTR use or trapping water, etc without serious impact on your primary goal, vs no gap at all.

4x 12mm would indeed be massive overkill, but a reducer might overcomplicate it. Regardless, this seems a promising way to attach... whatever is going to be attached. As you say, I will need some kind of spacer or nut to hold the aero cover at the correct distance from the lugs. The issue with just using a bolt and nut, however, is that to snug up the nut that holds the aero cover, I need to be able to access the backside of it while it is already on the wheel, which is another can of worms. Or, I can get lugs that are already the correct length, so they stick out of the hub, and give a flush surface to mount to. But, that was what the spike lugs were intended to do to begin with.


And there's still the matter of what to use as an aero cover. Let's say I got a simple aluminum disc and polished it, with a Honda logo sticker in the middle. Let's say it extends to within half an inch of the wheel's lip. How thick do you recking it should be so it remains robust? 0.5mm? 1mm? 2?

[freebeard]

I can't find my Moon disks (or anything else I look for), but I'd estimate 1/16" or 1.5875mm. Without the crown you'd want to go thicker. Why not get the real deal if you only need two.

I got this set of four disks with the mounting holes worn out at a swap meet for $5.

[j-c-c]

To heck with metal, I'd go carbon fiber, .045", alum .060" there are no normal significant forces at play other than centrifugal, and for this diameter I am assuming at non race speeds, minor. Road bumps would be biggest uncontrolled force, but heck normal hub caps stay on, mostly. You could go lexan at .125" but you would constantly be cleaning them to remove inside brake dust and you would need to make sure they are vented for heat related needed airflow. Not sure though how well they would hold up on a 0-150-0? mph timed run if you left the car sitting still after stopping: eek:

PS, all my dim above are for a flat disc, and any shape would add stiffness and thickness could be reduced further.

[Ecky]

My main issue is, the market here is smaller and has fewer things available. Anything ordered from overseas is more expensive. I need to be more deliberate about what I pick and order.

[j-c-c]

So titanium then is off the table?

I understand, I get carried away sometimes, alum seems like your best choice then?

[Ecky]

The carbon fiber disc idea is intriguing. I'll need to see if anyone makes them locally.