I've been wondering about 10" wheels.

It's generally accepted that Minis handle best on 10" wheels right? OK, but what i'd like to know is what makes the handling different between 10, 12 & 13" wheels? I broke it down into categories that I thought would make a difference:

1. Rolling radius
2. Rim offset
3. Rim width
4. Overall weight

Rolling Radius: 12" & 13" wheels are larger diameter, but the rolling radius is very close to that of the 10" wheel because of the lower aspect ratio of the tyre. I don't have the specs on hand but I have looked them up before and they are pretty close (i'll dig them up and post them when I get a chance).

Rim offset: I'm not sure how this varies between 10", 12" & 13" rims but you can get a 12" or 13" rim made with the same offset as a 10" so I can't see this as being a reason for handling differently.

Rim Width: 12" & 13" wheels are generally a bit wider than most 10" wheels but this isn't to say they have to be. I don't think this is a reason as to why they can't handle the same as 10" wheels either.

Overall weight: Is a 12" or 13" wheel and tyre heavier than a 10" wheel and tyre? If so, would this difference be enough to cause the handling difference?

It's my hypothesis that it's a combination of ALL of these factors that make 12" & 13" rimmed Minis seem like they don't handle as well as their 10" shod bretheren, not merely the fact the the diameter of the rim itself is greater. And therefor, if you were to match the width, offset, weight and rolling radius as closely as possible you would also be able to get the handling pretty close too.

Thoughts?

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Metal to burn, sparks to fly...

I Never really think about it.. But is it not because on 10s the body sits closer to it centre gravity... I think I remember reading in a visard the a mini still should be lowered a bit from std height to have best results due to understeer/ oversteer...

I think thats what it said

Or is it possible that mini's benefit from a little bit of tyre movement or sidewall flex (don't know the correct term) which isn't available with the lower profile tyres ? That's the only real difference I can think of . Maybe the suspension just works better with a little tyre movement than if it was all stiff ?

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Yep I reckon it's the combination of relatively high aspect ratio tyre, rubber suspension and our crap roads. The tyre has a bit of `give' on bumps & ripples, which is more than you can say for those rubberbanded phat 13s.. which should be OK on dead smooth stuff I guess.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

10s go better just because they dont fit an any other car.

How can i find out what rims / tyres my mini came out of the factory with? would it be listed on the net or even on the car somewhere?

i'm pretty much a car n00b so the answer to this is probably really obvious

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1975 Hairy Lime/White Clubby
Build Thread: http://www.ausmini.com/forums/viewtopic.php?f=3&t=80657

90% of Minis sold in Oz had steel 10" x 3.5" rims with 145R10 tyres (or equivalent crossplies). Judging from the photos of your car, that's what it has now, being a standard model Clubman. More upmarket models in the range (Cooper S, Clubman GT, S, SS, LS) had wider steel rims or alloys.

But just about everyone puts different rims on their Mini anyway.

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Brett Nicholson
Greendale (near Ballan) VIC.
1971 Morris Mini Moke
1966 Austin Mini
1965 Morris Mini Traveller
1973 LR Series 3 88
2007 LR Freelander 2

Thanks for that bnicho
Just one other thing, what was the profile of those tyres? 75?

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1975 Hairy Lime/White Clubby
Build Thread: http://www.ausmini.com/forums/viewtopic.php?f=3&t=80657

Can't remember the exact figure. It's either 80 or 82?

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Brett Nicholson
Greendale (near Ballan) VIC.
1971 Morris Mini Moke
1966 Austin Mini
1965 Morris Mini Traveller
1973 LR Series 3 88
2007 LR Freelander 2

I've always bee a 10 inch fan. Probably because I remember what a sensation they were when they first appeared on a mass production car. Somehow a Mini just doesn't look right on anything else but Mini siized 10 in wheels.

And then there's the go-cart like handling advantage, quicker acceleration, and uniqueness....

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Slide
1965 Mini Van (1360)
1970 Mk2 Cooper S (1310)
1978 Rover SD1 V8 (4.6)
1996 Land Rover Discovery V8 (4.0)

Back when released, an 850 on 5.20x10 crossplies and 3.5" rims could outhandle a Bugeye Sprite, no problem.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I met a guy at Rob Roy Hillclimb with a 1275 LS on 10 inch wheels (had cooper S discs front and rear). He believed that the side wall flex on the tens made it handle better and gave more warning if it was about to get loose.
To put S discs back and front the guy was obviously convinced tens were well worthwhile.

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Mini K, 1310, Jet Red/Crystal White Roof, Rover Interior

75 Clubman

I have heard quite a few reasons, but the most likely are probably something to do with the unsprung mass (10" alloys are between 3-4kg without tyre. Try and buy a 13" alloy that light), and affects of the large sidewall.

I personally think it is probably a combination, meaning over bumpy roads the 10's end up spending more time actually on the ground than a 13"er.

Klubman, i have also heard such things. Some people claim that as the car starts to loose traction around the corner on 10"s your halfway through the corner before rolling over on the sidewalls, and by the time its a problem your already out of it. On 13" skinny profile tyres you just loose the traction and have no "after effect". Not that i've ever had my Mini on 10s "roll" over on the sidewalls...maybe my tyre pressure is too high

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Mini - The Wizardry on Wheels!