Before anyone tells me that I'm nuts, don't do it etc, this is for very limited street use and mainly track time...

Has anyone here machined down rims to reduce the weight?
Did you had any cracking issues / how much did you take off?
Is there a general rule of thumb on how much you can machine away?
Anyone have contacts of someone who would be in the know for this in Brisbane?

Kuzzy

My mistake, had brake drums on my mind

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Ok, might have been a bit vague. I'm talking alloy wheel rims (Mag Wheels)

No vagueness Kuzzy, post was clearly marked as rims

Steve

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At a guess, anyone who does it for you isn't going to give you any guarantees they won't fail and won't want to hear about you needing them engineered - there's a lot of variables. Perhaps a race car engineering firm?

But have you considered weighing wheel and tyre combos, deciding what's lighter, selling your current wheels and buying a new set? The cost of machining is going to narrow the price gap between keeping your existing wheels and buying a new set.

What wheels do you currently have?

There are wheels, and there are wheels..
I just came back from the tyre shop, one Contessa has got about 100g of weights in it.
We tried with no tyre and it took 90g just to balance the rim.
Many of these old Oz mags were not machined inside the inner rim, this one is thicker one side, you can see the runout when spinning..

<edit> re the original topic, I am tempted to machine this one inside, where the manufacture never bothered...
Next time....

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I wouldn't do this. How much weight are you expecting to remove? Maybe 1kg on each wheel? Miniators are pretty light (10x5/5.5/6") and there are some other original mags that are pretty light. Yes it would be better for unsprung weight, but there are loads of places you can pull weight off the mini without affecting such a critical part as the wheel (rim cracking at 160 kmph ... bad news.)

All reliable ways cost money, the best bang for buck is probably the minfin alloy drums, or changing the front calipers for a lighter version.

I don't have any rims yet and have been trying to get info out of suppliers etc for weights of rims. Basically they have not been responding! All I want is some new period looking 10X6 rims, Mini Lites, Revolution 4 spokes etc...

Someone mentioned to me the Revolution 4 spoke can be machined down a fair bit..... Was just having a thought.....

I will get the mini fins, but at a later date. 1st I need to finish the car and get some good light weight rims. I would love Mamba's as they are light, but expensive and hard to get as they don't make them anymore.

Kuzzy

i think that the mini man matt had carbon fibre rims from memory or the doc one of the two had made a set up on here i could be wrong.



cheers TUCK3R

Yeah check with the Miniman he has some beut rims for sale at the Muster they were as light as a feather and made to be like that. I would not dream of machining down any alloy rim and any one offering to do it would have to have rocks in his head I recon. Think of all the liabilities attached.

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Surley if you have an outer rim wall thickness of say as an example 4mm thickness that has been machined down at the factory before sale to the public - and an inner rim surface that is much thicker say for example 8mm - you could safelty machine the inner rim to the same thickness - keeping away from webs etc and gain a weight reduction.

At the end of the day the factor of safety will be calculated on the thinner rim section and that should be about a factor of safety of 2 or more for a car wheel.

But how much weight would you be saving ? I understand the whole priniciple of unsprung weight and the benefits of light weight wheels but don't think it would be advisable to lighten fairly light wheels (compared to steel wheels) any further .

Maybe people with bare mag wheels can post the weight of them here for comparrison so you can get an idea of what's the lightest and go with that ?

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Now - I have not seen this myself or claim this is true - so don't call me nasty names - I have only been told, by a pommy bloke who I don't know on another Mini Forum that Revolution 4 spokes are 3.8kg from the factory and they can be machined down to 2.4kg....

Now I think that is a bit extreem if it is true, but surley there is a midway point.

Yes, I like your idea better though - anyone with some bare light weight rims willing to post the weights?