spyder alloy wheels - steel insert issue (in my opinion)

[laurenth]

Hi guys,
I recently purchased alloy wheels from spyder eng. The wheels have stainless inserts fitted and that's a good thing. However, I think the shape of those is rather wrong if not dangerous!
On steel wheels there is a cone and the spinners are matching the shape of this cone. There is a 8mm band of contact between the spinners and the steel wheels.
With those Spyder inserts, the band of contact reduced to....well......0.0001mm....Basically, there is no cone but a large radius on the insert!....
What do you think?
Any good or bad experience?
Any advice?
I don't want to loose all 4 wheels on the road!.....

Thanks for your help!
L

[GrUmPyBoDgEr]

Hi Laurenth,

What you are doing here is quoting "ideal World" conditions but in reality both the alloy wheels & the steel wheels will in theory have just a point of contact due to manufacturing tolerances etc. In reality that point contact should extend over a greater area due to material deflection/ plastic or elastic deformation.

I would advise you not to worry or to perhaps raise another question to those who have fitted those wheels to their cars & ask if the wheels have fallen off their cars.

Mr. Chapman did design his cars so that the wheels stayed on them until they crossed the finishing line but Graham Hill would have you believe differently

Nix f?r ungut
John

[AHM]

What did Spyder say when you asked them?

[GrUmPyBoDgEr]

What did Spyder say when you asked them?

Would you expect them to answer such a question with
"yes this is a major problem which we are investigating"

The mind boggles sometimes

[AHM]

No
I would expect them to give a technical answer as to why a cone should clamp on a radiused surface.

Someone designed it like that. The correct place to ask first would be the person selling it. If they didn't know they should find out.

Once they have answered then we can have a reasoned discussion - Who are we to say it is wrong?

Seems logical to me, but then my mind doesn't boggle.

[Pistacchio sprint 72]

Could you post a picture please?

[rgh0]

My original Lotus alloys appear to have a similar radiused stainless steel insert. It also appears that a flatter cone section is formed as the spinner is tightened and the insert and the alloy under it distort with the pressure.

cheers
Rohan

[GrUmPyBoDgEr]

O.K.
A larger contact area between the components will result in higher interface friction.
That would equate to underhead friction in bolts.
That friction requires effort & that, in effect lost effort, is not being transferred into the vital clamping force.

Some years ago there was a similar discussion & to be frank I don't agree with the arrangement on these wheels.
The earlier Two Gates made wheels from Spyder had a much more satisfactory "location" system but in my opinion the wheels now under discussion should provide the needed, safe clamping force.

AHM--Your reply implied that the original poster send his question to Spyder, but if you read his post again you will see that he was asking our opinion here on LotusElan.net

Nix f?r ungut
John

[AHM]

AHM--Your reply implied that the original poster send his question to Spyder

Yes, one of several things that can be inferred, which form a. my opinion and b. my advice.

If however you are after conjecture I'll add ....
- This is the only locator on the elan wheel so a narrower contact patch will give more accurate location.
- For the recommended tightening torque this gives the correct clamping force
- There is a patent covering other designs.

But I?m guessing, and another guess I?ll take is that the designer at a wheel manufacturing company knows something about their day job.

So my advice is to ask the right person, who should be happy to answer.

[Spyder fan]

A good point to raise is that Spyder don't make these wheels or the inserts. They are in fact genuine Minilites.

Now those guys know about wheels and I wouldn't expect an unsafe or indeed unsound product from them.

Use your wheels with confidence Laurenth

Regards

[adigra]

My newly purchased Minilites (directly from them), have the same insert. I am going to assume it's 100% fine.

[Pistacchio sprint 72]

Are they the same that TTR is selling? I understood the brand behind the sellers was either panasport or minilites...

[vernon.taylor]

Salut

I was kindly sent this to explain the difference between Rudge-type and Lotus knock-ons:

Hubs and Nuts.pdf

(762.28 KiB) Downloaded 378 times

So as long as your spinners are male and your wheel (inserts) female, epicyclic action should keep them tight.

However I think this depends on the assumption that acceleration forces are greater than braking forces (or vice-versa ) - so if your wheels fall off you're not using the driving style Colin intended!

I'm not sure but I think 26R Elans use harder materials for the hubs/spinners and so have higher torque settings for the wheels. This would explain why I recently saw a 26R with the opposite spinner thread to my +2 - once a certain degree of torque is reached it doesn't matter which direction the spinners are tightened. Apparently normal spinners/hubs/wheels can't take this level of torque without something splitting. I also suppose this 26R difference is so that a generic race mechanic doesn't get confused after an MG or Jag.

I imagine that the Elite and early Sevens with wire-wheels used Rudge-type spinners meaning that they tighten in the opposite direction to Elans/+2s - can anyone confirm?

@+

Vernon

[Chancer]

It would take either a very very highly powered vehicle, something like a dragster or defective braking system for the acceleration forces to be of a greater magnitude than the braking forces.

The above is based on the fact that most vehicles can brake to a halt in a much shorter distance than they can accelerate to the same speed.

The instantaneous torque when pulling away fram rest though I reckon is higher than when the brakes are first slammed on.

[Chancer]

It would take either a very very highly powered vehicle, something like a dragster or defective braking system for the acceleration forces to be of a greater magnitude than the braking forces.

The above is based on the fact that most vehicles can brake to a halt in a much shorter distance than they can accelerate to the same speed.

The instantaneous torque when pulling away fram rest though I reckon is higher than when the brakes are first slammed on.