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Discussion Starter #1
All,

I am becoming a little concerned that people may be becoming a little carried away with this wheel weight issue.

Firstly, I have real doubts that in a car with 160 bhp you can feel the extra resistance to spinning up under acceleration of the weight in the wheels in light(sorry) of the effort required to speed up 1400 kg (incl passengers and fuel). I also doubt that this would be very noticeable under breaking.

Secondly, I believe that when turning in the extra problems associated with fighting the gyroscopic forces involved would be marginal in a car with power steering (big issue on a bikes at high speed). I also think that the extra 4cm of rubber on the road, as well as the smaller sidewall height may well cancel this out. Also, these forces would be highly speed dependent, and in a country like Aus where anyone going over 110k makes you public enemy number 1 I don't think it's that big an issue.

Thirdly, the effect on the ride and grip on bumpy surfaces again would only be significant at higher speed. Is this enough to offset the grip of the extra rubber? On smooth roads you would certainly be ahead with the bigger boots.

Lastly, I am a little concerned about very light wheels on rough roads. I have bent alloys before, and it's not pleasant. I'd rather have a strong wheel, than a really light wheel with 15mm more sidewall.

All of this is IMHO. While I understand that the lighter the wheel the better, I still think that for road use tyre pressures and precise wheel alignment will have a far greater influence on the handling of the car than the differences in the wheels.
 

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- I must warn you of a drastic misunderstanding:

"Lastly, I am a little concerned about very light wheels on rough roads. I have bent alloys before, and it's not pleasant. I'd rather have a strong wheel, than a really light wheel with 15mm more sidewall."

Any Cast wheel is the weakest aluminum wheel possible. There are air bubbles (in layman's terms) in the casting which allow the wheel to completely shatter.
If the lightweight wheel you're comparing to is a forged one (most good lightweight wheels are) then you're way out of line. The Forged wheel is much stronger, regardless of the weight. The Cast wheel is always much weaker, regardless of the weight.

Please don't assume that just because a wheel weighs a lot that it's strong. It's NOT.


- You can feel the difference in acceleration, I've done it back to back between my father's identical car with 17 S-spokes and mine with wheels and tires that weight 15lbs less per corner.


- The grip on bumpy surfaces is the WORST place for a heavy wheel. I was very aware of unsprung weight problems, but never experienced it until I picked up my car with 17's and drove a couple hundred miles on them. It was the first thing I noticed about the car (sadly) because I had never had very heavy wheels.


- On smooth roads, it's not always better to have "bigger boots", and certainly not ones with heavier rotational mass.


Like you said, it's your opinion, and that's fine, but you're stating your argument as fact.

In the end, it's just like a faster computer. As long as you never sample the new one, you won't miss it.
 

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Discussion Starter #3
Ok,

Perhaps I left myself open for a little misunderstanding. I was comparing the 17" optional mini wheels to the standard fit 16"s (either of them). I've no doubt that in demanding applications a good pilot may be able to pick a difference between the standard fitment wheels, and a set of really good aftermarket wheels and tyres.

However, my contention is that the difference between the standard mini 16" and 17" on the road probably wouldn't be that great. Especially in Aus where we are ruled by speed Nazi's.

In the thread below some people are saying that the difference between wheels and tyres could leave one mini feeling between 200 and 400 kg heavier than another on standard wheels. That means that a set of light wheels and tyres could be expected to give a similar difference in acceleration that there is between a Cooper and a S. Hmmm, sounds a lot to me.

http://www.mini2.com/forum/showthread.php?s=&threadid=10604

Now I have not been in a position to drive the two back to back as mini's are still a little scarce here. However I do have some experience with light cars with light wheels.

I have driven several Lotus, and currently own an Elan (original). Recently I had cause to drive a friends Elan that had a substantially heavier and grippier wheel/tyre combination. I must admit that at street speeds the main difference was more grip and better turn in.

As for strength, I guess it is conceiveable that the standard fit 17" mini wheels aren't any stronger than the 16"s. I know I've seen friends with very expensive forged race wheels bend them on minor pot holes.

All I was saying was we need a little perspective here.;) ;)
 

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swamos said:
Ok,

Perhaps I left myself open for a little misunderstanding. I was comparing the 17" optional mini wheels to the standard fit 16"s (either of them). I've no doubt that in demanding applications a good pilot may be able to pick a difference between the standard fitment wheels, and a set of really good aftermarket wheels and tyres.

However, my contention is that the difference between the standard mini 16" and 17" on the road probably wouldn't be that great. Especially in Aus where we are ruled by speed Nazi's.

In the thread below some people are saying that the difference between wheels and tyres could leave one mini feeling between 200 and 400 kg heavier than another on standard wheels. That means that a set of light wheels and tyres could be expected to give a similar difference in acceleration that there is between a Cooper and a S. Hmmm, sounds a lot to me.

http://www.mini2.com/forum/showthread.php?s=&threadid=10604

Now I have not been in a position to drive the two back to back as mini's are still a little scarce here. However I do have some experience with light cars with light wheels.

I have driven several Lotus, and currently own an Elan (original). Recently I had cause to drive a friends Elan that had a substantially heavier and grippier wheel/tyre combination. I must admit that at street speeds the main difference was more grip and better turn in.

As for strength, I guess it is conceiveable that the standard fit 17" mini wheels aren't any stronger than the 16"s. I know I've seen friends with very expensive forged race wheels bend them on minor pot holes.

All I was saying was we need a little perspective here.;) ;)
Not everyone will be too concern or will even care about the difference in wheels weight. But believe me when I say you can tell the difference between a light set of wheels and a heavy set. I don't remember myself or anyone ever quoting 200-400kg weight saving (you sure it wasn't lb?), but if the saving of the wheels is extreme enough then yes that could be a possibility!!! I drove two Cooper S back to back, one with 16inch x-lite (about 16lb) and the other with 25lb S-lite. The tyres are reportedly about the same. I certainly felt the difference. We are talking 9 lb per corner here, yet it made a big enough difference to me. Next time you get a chance, drive the two combo I mentioned, do some slalom menouveur and see if it makes a difference to you. Also as Garfield said, the bumpier it is the more profound the difference. I did not like the handling characteristics of a car with S-lite on a bumpy road, but the next time I went back with the x-lite I loved it. Coincidence? I don't think so!!! Anyway, these are my views based on my experince. :D
 

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Discussion Starter #6
WAY said:

I drove two Cooper S back to back, one with 16inch x-lite (about 16lb) and the other with 25lb S-lite. The tyres are reportedly about the same. I certainly felt the difference.:D
I look forward to doing this comparison myself on our first mini club run up here :D :D :D :D

By then at least we'll be able to compare the vehicles when they are run in, and have known correct wheel alignment and type pressures.
 

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Garfield said:
Any Cast wheel is the weakest aluminum wheel possible. There are air bubbles (in layman's terms) in the casting which allow the wheel to completely shatter.

You can feel the difference in acceleration, I've done it back to back between my father's identical car with 17 S-spokes and mine with wheels and tires that weight 15lbs less per corner.
Of course you're right in comparative terms, but I highly suspect that all of the relatively cheap, heavy, cast aluminum rims available for the MINI are plenty strong enough that most of us will have them for the life of the car, including those of us living in cities with pot-holes.

Incidentially, what is the observed difference? Subtle, obvious? In a 0-60 run, or a standing 1/4 mile, what kind of difference are we talking about? A hoodlength? A car length? An embarrasingly obvious win?

Just curious, because without stating any facts - just opinion, my MCS with the 17" rims feels fast, turns impressively, and doesn't feel harsh or fragile. I did drive the demo car, and I can't say I remember much difference, although about a month passed from last test drive to ownership.
 

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Unsprung weight - the bald facts!!

2 things to consider with regards to unsprung weight...

1. Unsprung weight measures the weight of everything outboard of the suspension links. For example say a wheel weighing 50lbs goes over a 5G bump - the vertical force the springs/shocks have to contend with is therefore 5*50=250lbs. A wheel with unsprung weight of 30lbs going over the same 5G bump will only have a vertical force of 150lbs. As you can see this is a 67% increase on the lighter wheel - a not inconsiderable amount that the suspension has to cope with - thus reducing both the level of grip and the timing of the grip as the suspension will travel more slowly on bump and rebound.

2. Reduction of rotational mass. The lighter the unsprung weight is (and even how the weight is distributed on the wheel ie. if the wheel has all it's weight in the middle or on the outside) the less power will be required to accelerate the wheel. Each lb less that the car has to rotate at the wheel is equivalent to @ a 10 lbs weight (apparently) reduction of the car itself. This is an amazing number and hence the reason why a 50lb saving can equal such a large saving @500lbs in "virtual" car weight.

Anyway, this is what I have gleaned from limited research - it would pay to do your own - as for subjective and actual research and how this translates into how the car goes - that will have to wait a few weeks!!
:D :D
 

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Nice Elan BTW Swamos.

Unsprung weight as far as performance cars go is an absolute killer. The theory here has been gone over previously so I won't go into that, as I've said on a previous thread I've a PRB Clubman that I sprint and I fitted lightweight 3 piece 13" rims with really lightweight road legal Formula Ford tyres replacing cast 14" rims with R spec rubber. Difference, massive on the track, definately accelerates faster, turns in better etc etc.

On a road based Mini, forget about it. I'd argue the case if you were fitting 19" rims over 16" but between 16/17" factory rims?? get what you think looks better (I'm going 17"), I would be interested though in the weight of R90's to the 17" S-spoke rims though.

As far as damaging a rim on 17's compared to 16's with run-flats you won't have a problem as the sidewall is quite thick compared to a normal tyre.
 

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For goodness sake.

The 17" S-Spokes are NOT heavy. They may be heavier than the 16" X-lights etc, but compared to a steel wheel they weigh next to nothing.

You want to go racing and knocking 9/100th's of a second off your lap time, or 1 minute off your dash to the corner shop, of course go and reduce unsprung weight etc. I'm buying the car for the real world. 205 v 195 = more grip.

I'm with you swamos. Plus the S-spokes look fabulous as a bonus.

:)
 

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Basil said:
For goodness sake.

The 17" S-Spokes are NOT heavy. They may be heavier than the 16" X-lights etc, but compared to a steel wheel they weigh next to nothing.

You want to go racing and knocking 9/100th's of a second off your lap time, or 1 minute off your dash to the corner shop, of course go and reduce unsprung weight etc. I'm buying the car for the real world. 205 v 195 = more grip.

I'm with you swamos. Plus the S-spokes look fabulous as a bonus.

:)
Better still Basil, go after market. Lighter wheels (half the weight) and wider tyre (215) = Even more grip and better performance!!! :D Too bad it is costing me 4 times more than it would have if I had just specced the car with the S-lite. :(
 

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Basil said:
For goodness sake.

The 17" S-Spokes are NOT heavy. They may be heavier than the 16" X-lights etc, but compared to a steel wheel they weigh next to nothing.

You want to go racing and knocking 9/100th's of a second off your lap time, or 1 minute off your dash to the corner shop, of course go and reduce unsprung weight etc. I'm buying the car for the real world. 205 v 195 = more grip.

I'm with you swamos. Plus the S-spokes look fabulous as a bonus.

:)
Ok, I'm not even going to argue, just go to this site ( http://europeanspeed.com/wheelweights.htm ) and do the percentages on how many 17's are lighter and heavier than the 25lb S-Spokes. Trust me, even in the stock 17" wheel category, they're heavy. I do know that the stock 17's on an Audi S4 are about 26-27 which is rediculous also.

I didn't buy anything exotic. I dropped back to aftermarket 16's, put a regular tire on, and lost 15lbs per corner, BIG difference.
 

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Garfield said:


Ok, I'm not even going to argue, just go to this site ( http://europeanspeed.com/wheelweights.htm ) and do the percentages on how many 17's are lighter and heavier than the 25lb S-Spokes. Trust me, even in the stock 17" wheel category, they're heavy. I do know that the stock 17's on an Audi S4 are about 26-27 which is rediculous also.

I didn't buy anything exotic. I dropped back to aftermarket 16's, put a regular tire on, and lost 15lbs per corner, BIG difference.
How much did the run-flat weigh and how much did your normal tyres weigh???
 

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Run-flat = 25 lbs
Wheel = 25 lbs
(a bathroom scale used for all measurements)
Enkei RPO-1 = 14 lbs
Falken Azenis 215/45R16 = 21 lbs

The Falken is still a heavy tire too, the Toyo T1-S is about 18lbs in this size. My Hoosier race tires are 16lbs.
-----

Ok, I did the math myself on that site (what a pain!)
Of the 485 17's including ALL widths (some be 10 inches wide!), only 60 wheels were over 25lbs.
That's 92% of the wheels listed being lighter than the MINI's 17's.

In the 17x7's only with 210 listed, 16 were over 25lbs, so 87% of those were lighter.

ANYway, you get my point. There's plenty out there to loose weight, even with cheap replacements.
 

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Garfield said:


Ok, I'm not even going to argue,
Glad to hear it.....but your missing my point, and swamos's point also.

In real world road situations the differences are completely academic.

As I've intimated, if your worried about it, go for your life and fit the lightest "road" wheels you can. So you can get down the road that 1/4 sec faster than me with my overweight S-spokes. :rolleyes:

:)
 

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Oh, I fully realize both of your points, which is that you don't realize the real-life implications of heavy wheels. I understand that most people will never drive their MINI to their full potential, just like most SUV's never go off road.

I couldn't give a rats ass about that 1/4 sec you're talking about, I leave that for the race course, not the road.
What I'm talking about is the bump on the turn that throws your MINI out of whack and difficult to control because the shocks couldn't react fast enough due to heavy wheels. In the same situation, my MINI's shocks will do their duty and plant the tires where they belong.
OR, when I have to make an emergency stop because of the situation in front of me and I stop in say 75ft, but you run into me because your MINI brakes from the same speed in 85ft.

The performance may be acceptable to MINI, it's just not to me.
Every SUV/Truck out there has achieved "acceptable" performance...go figure.

Look to this thread, http://www.mini2.com/forum/showthread.php?s=&threadid=10343 I'm not the only one who realizes this. This person just didn't know why the handling and response was poorer than expected.

If you're going to drive around at 5mph below the speed limit and never test the car's ability, then by all means ignore what I'm saying. I have no problem if you bought the car for people to wave at you.
But, if you have any idea of finding the limits on the car, by accident or on purpose, then this becomes an issue.

I will try to go out and prove it back to back with another S on the 17" S-spokes and post the results, take them however you like.

Keep in mind, I'm still trying to sell my S-spokes, and this isn't a very good sales pitch. So obviously you can see what's more important to me.
 

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Garfield said:

What I'm talking about is the bump on the turn that throws your MINI out of whack and difficult to control because the shocks couldn't react fast enough due to heavy wheels. In the same situation, my MINI's shocks will do their duty and plant the tires where they belong.

Look to this thread, http://www.mini2.com/forum/showthread.php?s=&threadid=10343 I'm not the only one who realizes this. This person just didn't know why the handling and response was poorer than expected.
I can't agree more. When I replied to that thread above, I was also like S200, not aware that the bounce was due to the heavier 17 inch. I mean by that stage I had driven the car quite a few times, and the 17's were fine when I threw the car around the race track. But it all hit me when I took another Cooper S with x-lite to the same bumpy b-road and come away smiling. Of course, this irregularity in handling will never be felt if you don't push the car to maybe say 8/10th. I don't think many people on the board will ever attempt that, as the Cooper S limit is very very high.

I think we all have different style of driving and preference. I mean I like pushing my car to it's limit (or mine) from time to time, and it's times like this that I need the wheels to be light and perform as I desire. Basil and others may not, or they may like the way the car bounces off course. To each their own I guess. Let's keep this as a debate, and not get personal about it. ;)
 

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again from personal experience.. and im sure i've said this before on another thread debating this... (side note- i think we must b bored.. im sure every debate on this board has come up more than once since i been here :) )

on my last car i got much heavier pretty lookin chrome rims and sure it felt a bit funny at times.. it didnt seem to go as good i was never that sure till i got defected for them (dont ask) and put the stockies back on to clear the defect the difference was so amazing the car handled like i always thought it did but wasnt that sure since so much time had passed.. it picked up so much better, it almost felt like a different car i didnt really wanna put the chromies back on.. but they looked so much better :) so i guess thats how it is with the S-lite 17's people think they look better.. so thats what they'll go for.. but trust me, you will be missing out

personally i think the range of rims for the mini is very average the R90's are by far the best but silly expensive. I just went with the x-lites cause they looked better 2 me, a no cost option, lightest, and i probably will replace them at a later date

btw the grip issue between 16's and 17's i think is a bit misleading the lower weight would probably mean u'd pull up quicker in an emergency.. and less boucing around on bumpier surfaces as the heavier wheels will tend to do negates the need for as much tyre area on the road and ontop of which u have ABS DSC etc etc

anyways another lengthy rant from moi.. take it with the grain of salt it was intentioned
u want those S-lites u go right ahead and grab em, i'll just cringe everytime i see em.. im not thier biggest fan :)
 
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