Why are the wood 6 bolt pattern steering wheel all dished

[xb-60]

Firstly, if you do buy a good quality “flat” steering wheel – for example a Moto-Lita – you won’t have any problems. In fact, most, if not all of the Moto-Lita wheels to suit period Jaguars are flat, and they would certainly be strong enough.

To your question –

Originally Posted by Michael C Henry

Why would a dished steering wheel version be stronger than a flat...

…. If you consider a steering wheel, with the horizontal direction being the X-axis, the vertical direction is the Y-axis, and the fore-aft direction is the Z-axis.
With a flat wheel, the Z-axis is zero length, so there is no extra resistance to a deflection of the rim in the Z direction.
Add Z depth, as is the case with a dished wheel, and you have in fact triangulated the wheel (as Gary has mentioned) in the Z direction, making it much more able to resist bending when deflection forces are applied.

Cheers!
Glen

[eschaider]

The pic below is a "flat" Moto-Lita steering wheel for a Jaguar. Predictably, because it is for a Jaguar, it it uses a Jaguar 77.8mm PCD with six attaching holes.



From the picture above it appears that the Jagusr attachment hole spacing is not equidistant.

The challenge with using this wheel on a Cobra is both the attaching bolt PCD (most Cobra's use a 62.5mm PCD) and the fastener placement on the PCD. Cobra's use a different non evenly spaced bolt pattern and Jaguar (appears) to use their own proprietary pattern. The difference in fastener placement and spline positioning on your steering hub will produce a steering wheel 'clocking' issue, when the car is going in a straight line, that will need to be resolved.

If this steering wheel or one similar to it is what you are looking for you have several choices;

Choice 1:

Make or have made an adapter to allow use of this (or similar) wheel on your existing Cobra PCD and attaching bolt pattern.

Choice 2:

Hake or have made a new hub for your steering column with the Jaguar attaching bolt pattern and PCD

Choice 3:

Check your existing hub to see if it is large enough to accommodate the mounting flange surface and register the Jaguar wheel requires. If it is, then remove the hub, to allow remachining of the hub to provide a Jaguar style register and attachment holes and reposition it on the steering column.

If this alternative is chosen don't forget to redesign the hub so the steering wheel is at 12 o'clock when the car is going straight forward.

Choice 4:

Find a Steering wheel manufacturer that is willing to make a steering wheel you like that will attach to your existing steering wheel hub.

Choice 5:

Use a commercially available dished Cobra steering wheel and forego the flat wheel design you are looking for.

I may have missed something but I believe those five choices are logically the alternatives available to you.

The only thing that remains for you to do, is to choose the alternative you prefer.


Ed

[patrickt]

Choice #1. Just order a circular piece of billet aluminum off one of the internet metal suppliers. They'll cut it in a circle to your specified diameter and it will look perfect. Choose a thickness that appeals to you, allows for countersinking, and drill it appropriately. That's less than a two hour job and it will look OEM if you do it right.

[eschaider]

Originally Posted by patrickt

Choice #1. Just order a circular piece of billet aluminum off one of the internet metal suppliers. They'll cut it in a circle to your specified diameter and it will look perfect. Choose a thickness that appeals to you, allows for countersinking, and drill it appropriately. That's less than a two hour job and it will look OEM if you do it right.

— a wise man ...


Ed

[xb-60]

Originally Posted by eschaider

....it appears that the Jaguar attachment hole spacing is not equidistant.....

Flat Moto-Lita wheels for Jaguars come with a few different attaching hole patterns....

[eschaider]

Originally Posted by xb-60

Flat Moto-Lita wheels for Jaguars come with a few different attaching hole patterns....

You are right, Glen!

Although I skipped the large PCD and 9 bolt attachment scheme wheels because of the additional complexity involved in adapting them, that last Jag wheel in your line up escaped me.

If I am not mistaken, that is a Mk 2 type Jaguar wheel. The PCD looks quite similar to the 62.5mm Cobra PCD and might provide a good alternative starting point — obviously still requiring an adapter be made and of course proper clocking of the new wheel.

Thanks for the search effort and the heads up. I should have found that wheel — ahhhh, the advancing years .


Ed