Lotus Elan

Hub and Spinner Direction: Mystery and Controversy

PostPost by: patrics » Fri Sep 14, 2018 10:15 am

Hi,
I think the main reason people have had trouble with wheels coming loose is that they have restricted the rear brake performance to a point that there is not enough braking torque to keep them tight. If this is the case then swapping rear hubs from side to side would stop the wheels coming loose.
On my car I had the opposite problem where I couldn’t get the wheels off - have now changed to bolt on hubs and am much happier.
Also I think there are a lot of worn out hubs out there - comparing my Plus 2 hubs to my S4 and there is a big difference in wear.

Regards
Steve
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PostPost by: Panda » Tue Sep 25, 2018 7:43 am

Hi,
My 200 hp+ racing 26R replica using TTR hubs has them fitted LH thread to Rh side and Rh thread to Lh side as per Lotus racing 26R recommendation. I tighten them to 200ft lbs and have never had a problem in 3 years of racing.
Actually, I do find they are extremely hard to undo, needing a very long bar and large hammer on the removal tool!
Alan P
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PostPost by: rgh0 » Tue Sep 25, 2018 11:35 am

Sounds like if you do them up tight enough it does not really matter which hubs on which side :lol: This actually makes sense from an engineering perspective as compression on the nut to wheel interface at high torque loads would make the weight of the car on the hub irrelevant

Personally I will stick yo my bolt on wheels :D

cheers
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PostPost by: Andy8421 » Tue Sep 25, 2018 12:34 pm

Panda wrote:Hi,
My 200 hp+ racing 26R replica using TTR hubs has them fitted LH thread to Rh side and Rh thread to Lh side as per Lotus racing 26R recommendation. I tighten them to 200ft lbs and have never had a problem in 3 years of racing.
Actually, I do find they are extremely hard to undo, needing a very long bar and large hammer on the removal tool!
Alan P

That's great, but the correct engineering approach would be to have the RH thread on the RH side for Lotus 'male' nuts, and the opposite for RW nuts.

Have a look at

https://en.wikipedia.org/wiki/Precession_(mechanical)

It explains the effect well.
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PostPost by: 1owner69Elan » Wed Sep 26, 2018 2:51 am

rgh0 wrote:Sounds like if you do them up tight enough it does not really matter which hubs on which side :lol: This actually makes sense from an engineering perspective as compression on the nut to wheel interface at high torque loads would make the weight of the car on the hub irrelevant

Personally I will stick yo my bolt on wheels :D

cheers
Rohan


I think what Rohan points out that the vertical load from vehicle weight is irrelevant if the spinners are torqued up makes sense. So, do what you want as far as spinner “handing”. Just make them tight.

And maybe check periodically.
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PostPost by: Andy8421 » Wed Sep 26, 2018 7:41 am

Given Mr Chapman's well deserved reputation for keeping costs down, if he could have got away without the additional costs of having left and right handed spinners and hubs, I am sure he would have. The effect was clearly significant enough for Chapman to spend some money on it.

Reading the Wikipedia article I linked to above further, the effect is present even for tight fittings with no apparent movement - the micro deformations of the material due to its elasticity as it is loaded an unloaded are sufficient to cause the effect to occur. Personally, I would rather have this effect trying to tighten my wheel nuts up rather than try and loosen them.

My guess is that with the very low mileage Elans do today, and the relatively frequent removal and refitting of wheels, that the effect doesn't have time to manifest itself. Back when a wheel could be in place for 000s of miles with the nut not being touched, it must have mattered enough for Chapman to spend the money.
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PostPost by: Craven » Wed Sep 26, 2018 7:55 am

Remember these cars were in a competitive market place, wire wheels with spinners was a desirable option on nearly all sports cars MG’s Jag’s etc. I think if they could have got away with it Lotus would have stayed with bolt on wheels.
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