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Discussion Starter #1
Been pondering some shiny new wheels, and on scanning the excellent Aftermarket Wheel Gallery (thanks Miniac) I also started to wonder about weight.

I've read a few threads about the value of lightweight wheels, unsprung weight, etc. BUT my question is this:

Will a normal bloke, like me, who doesn't autocross, go on track days, or carry a GPS performance meter in the car REALLY notice the difference by fitting lightweight wheels & tyres?

As a point of reference, I've considered replacing the S-spokes - 11.4kg / 25lbs - with OZ Superleggera - 6.8kg / 15.4lbs... and also changing from runflats to normal rubber with the associated weight saving.

So, what do we think?
 

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MINI2 Master BLASTER!!!!!
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And I'm getting the same wheels the look awesome check these 18s out! Don't forget to lower your puppy :D
 

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Mini Mod
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Along those lines. Remember 18s are heavy as lead.
If you want light, they're not the answer.
Tires cost a bit more too.
 

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Discussion Starter #5
But surely a lightweight 18" will still be significantly lighter than the S-spoke?
And I would guess that a standard 18" tyre will still be cheaper than a 17" runflat?
 

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Discussion Starter #6
Another question...

Will a 20kg reduction in UNSPRUNG weight (ie wheels & tyres) be more noticeable than a 20kg reduction in SPRUNG weight (ie stripped interior or whatever)?
 

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MINI2 Master BLASTER!!!!!
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The 18" Superleggeras only weigh 7.5kg, thats still 3.9kg (15.6kg total saving) lighter than the S Spokes!
So you can see they aint heavy as lead. I found a set of 2piece wheels that are 18x7.5 and they still lighter than the S spokes by 2kg.

Yes 18" tyres are slightly more expensive, IIRC about £400-£500 for a set of Toyo Proxies but probably around the same as runflats.
 

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stuartkey said:
Another question...

Will a 20kg reduction in UNSPRUNG weight (ie wheels & tyres) be more noticeable than a 20kg reduction in SPRUNG weight (ie stripped interior or whatever)?
Yes it will, but less weight anywhere eg sprung or unsprung will make a difference.

Simple rule, you notice what you car is like when you say have one passenger, you notice its abit slower, whne its only you in the car its much nicer, same thing really, but you won't notice 20kg too much.

Unsprung wise you will notice your car is easier to steer and will handle better due to the loss in weight, which can help to lessen damaging effects on the suspension apparatus.

Another simple analogy,( in know its not car related but it will give you a jist of what I mean) Imagine putting on really heavy boots on your feet, you notice you cannot run as fast as you can't raise you legs quickly enough for each step you make. whne you have lightwieght traniers on you notice you can run much more easily.

Same thing kinda applies to wheels the less weight the easier it is for your car to accelerate and brake.

Hope I've helped.
 

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JCW No. 1459
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stuartkey said:
Another question...

Will a 20kg reduction in UNSPRUNG weight (ie wheels & tyres) be more noticeable than a 20kg reduction in SPRUNG weight (ie stripped interior or whatever)?
Maybe wrong but the answer would have to be yes ... reduction in weight for wheels / tyres also reduces rotational inertia of the wheel, thereby reducing work required to turn the wheels and improving responsiveness ... not to say that any reduction in weight wouldn't be of some benefit (as long as the reduction did not significant alter weight distribution ratios)

Larger wheels inherently have a greater rotational inertia than smaller wheels (mass of rim is further from the centre of rotation) and therefore will always be harder to spin up ... this has to be balanced with the fact that larger wheels typically accept wider tyres that provide increased contact patch and hence traction ...

Bit of a juggling act ... personally I think light weight 17" are a good comprise between looks, handling and performance but I suspect that opinions will vary ;)
 

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warped said:
Larger wheels inherently have a greater rotational inertia than smaller wheels (mass of rim is further from the centre of rotation) and therefore will always be harder to spin up ... this has to be balanced with the fact that larger wheels typically accept wider tyres that provide increased contact patch and hence traction ...

Bit of a juggling act ... personally I think light weight 17" are a good comprise between looks, handling and performance but I suspect that opinions will vary ;)
I totally agree with you there, but would like to add a point. The overall diameter of a wheel tyre combination can be kept the same, this relates to tyre thickness. 17" wheels on the MINI have a tyre thickness 45, whereas 18s have 35mm of thickness to compensate for the overal diamter of the wheel. I may be wrong but an 18" tyre say 215\35 is similar in weight to a 17" 215\45.
 

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Discussion Starter #11
Great info guys, thank you very much!

I'm going out now, will ponder the finer points raised here and probably come back with more questions :rolleyes:
 

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Ibb said:
I totally agree with you there, but would like to add a point. The overall diameter of a wheel tyre combination can be kept the same, this relates to tyre thickness. 17" wheels on the MINI have a tyre thickness 45, whereas 18s have 35mm of thickness to compensate for the overal diamter of the wheel. I may be wrong but an 18" tyre say 215\35 is similar in weight to a 17" 215\45.
Isn't the diameter that is the killer its the weight distribution :(

Rotational inertia is very dependent on how mass is distributed ... a wheel with most of its weight close to the centre of rotation will have considerably less rotational inertia than a wheel with a lot of it's weight at the rim ... I can't remember the equations anymore but the difference can be quite dramatic

Larger wheels therefore tend to have greater rotational inertia than smaller wheels even though they may weigh the same ... a lot can depend on the tyre though, as being the farthest point from the centre of rotation, they can affect the weight distribution a lot ... needless to say this is one of the reasons that the runflats don't exactly cover themselves in glory :D
 

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Very true Warped, I new about the inertia, was just pointing out about the tyre difference, I wrote my paragragh abit awkward looking back on it.

But as they say 2 heads are better than one, hopefully we've managed to get the main points across to Stuart
 

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Discussion Starter #15
OK, all good sound logic, I like logic.

Hence the F1 wheel: relatively small diameter wheel with large profile rubber = light, low rotational inertia.

So its the usual compromise situation. Do you want the looks or the performance? Best performance would be to actually down-size alloys, but best looks are probably from up-sizing & lowering ride height.

Bugger.

I want both!
 

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MINI2 Master BLASTER!!!!!
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Quick Solution = Get a set of 17s and lower the car! :D

Actually lowering the car gives you better handling characteristics, but a harsher ride. Have you noticted how low Touring cars are? They're real dang low!

17s will give you the best of both worlds, you have nice style, but your ride quality will still be comfortable even when lowered and you will have more grip unless you get a wide set of 16s.

But if like me, you want more emphasis on style. I've really been quizzing myself for like a 2yrs now, I've finally decided to go 18" to really appreciate the MINI's acceptance of this size. Don't get me wrong tho, I still want a nice set of light wheels so I can get the most out of my MCS when it arrives, with the use of 18s. As you will notice I'm gonna be biased to 18s.

I'm going with 18s(must be lowered tho or you look liek 4x4) because they look real good like in the earlier pic I posted, plus with the OZ SuperLs you won't really notice too much, but be warned the lower profile tyre will mean a slightly harsher ride, but more comfortable than the JCW 18s with Runflats.

I believe the MCS posesses enough Torque that you probably won't notice a difference between 17" SuperLs and 18" SuperLs. Afterall the MINI was designed to accept 18s with no mods required to the wheel well or arches, unless you go for 8"+ wide wheels.

At the end of the day only a minority of us will use our MINIs for racing and all the other stuff. I just want a nice looking car with nice wheels that can also help my car perform better

Thats my personal opinion.

What would really help you decide is just to do as much searching as you can for pics of the MCS with 18s and decide whether its for you
 

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I am also thinking about getting some super-legs for my cooper s. Apart from the fact that they look awesome, the other reason I want these over other alloys is the big weight saving in comparison to the s spokes and the respectable-ish price. I will probably stick to 17s though, and then lower the car, as I think the ride is already about as stiff as I would want it. (Lighter wheels should improve the ride slightly?) I also read in another post just before I became a member, that someone had fitted the Hartge lowering springs, which lowered the car (obviously!) but also improved the ride! This might also be a good idea.
Does anyone no if I could have the super-legs fitted straight to the runflats? The tyres are 205 45 17s.
One more question, oz had a wheel called the forgiata(?) a polished version of the super leggara. I saw it on the oz website, but they have since dissappeared. Anyone no if you can still get these?

Cheers for any help!
 

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MINI2 Master BLASTER!!!!!
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Yeah the Forgiata are nice, but for some reason have gone missing! I wanted them!
 

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Now With More Cowbell
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I notice a vast difference between my OEM S-lite 17" rims and my 15" winter rims.

The 15" rims are at least 5 lbs lighter per corner, and although I don't have comparative weights on the tires, I would guesstimate they're comparable, since my winters are non-runflat and 10mm narrower. The difference in throttle response, resistence to tramlining and ride compliance is shocking.

-CW
 

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MINI2 Master BLASTER!!!!!
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One thing for sure, you'll like the less weight thats for sure! You will have more fun with your MINI
 
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