Grip level

Author
Discussion

vrooom

Original Poster:

3,763 posts

274 months

Monday 2nd February 2004
quotequote all

Hiya Minis lad!

I got 13x7 superlites with bridgestone tires. i would like to downside to smaller sets, 12x5??. im qute impressed with grip of current tires.
would grip be better or less grip if i go for smaller rim with good tires?

jay

miniman

26,309 posts

269 months

Monday 2nd February 2004
quotequote all
Hmmm... I'm thinking of doing the opposite (upgrading to 13x7 rims from my existing 12x5's). My big concern is the tales of poor handling associated with the bigger wheels, and the bodywork chopping that is required. I may opt for a set of 12x6 deep dish Superlites instead.

Not sure how the grip would be affected by going for smaller wheels. I would imagine it is the width of the tyre in contact with the road that defines the grip level, so in theory perhaps a 7 inch tyre would have a little more than a 6. However, the experts on here may tell us that the 6 inch tyres give ample grip for a Mini anyway.

vrooom

Original Poster:

3,763 posts

274 months

Monday 2nd February 2004
quotequote all
Its pretty hard to find 12x6 or above rims.

I guess the width do affect the grip level.
i has 12x3.5 as standard rim before, the handling was piss awful, slides everywhere, but then the tires is worn moulded tires.

reason to change the superlites to smaller tires is i sick of fixing the bearings, and bump steer.

Jay

miniman

26,309 posts

269 months

Monday 2nd February 2004
quotequote all
vrooom said:
Its pretty hard to find 12x6 or above rims.


That's true indeed. I've been looking for them for a while - looks like Superlite / Ultralite have finally brought out a set. There's a few adverts in the latest Minimag / Mini World. Can't find anything on the web so far.

Cooperman

4,428 posts

257 months

Monday 2nd February 2004
quotequote all
IMHO 13" wheels are horrible. They may look very nice, but they don't do anything to improve performance, and they do indeed 'shag out' the wheel bearings.
I reckon a 5" x 12" is about the optimum size with a 165 width tyre. Increasing the wheel width just puts the tread down onto the road in a more stable manner making the sidewall sit more vertically. However, too wide and the effective track centre-line moves outboard, with handling and suspension geometry implications.
With a radial tyre the sidewall mean centre-line should be as vertical as possible and the 'footprint' with a 165 section at a nominal weight of around 740kg (which is about what a Mini weighs) is about ideal. Wider tyres give a greater contact area which, in turn means a lower contact pressure. Lower contact pressure is no problem in the dry, but in the wet it means that there is less "squeegee" effect to clear the water - hence aquaplaning will occur at a lower speed.
For ultimate handling a 5" x 10" wheel with 165/70x10" tyre will always be the very best and will give reduced wheel bearing wear. The suspension geometry wes, remember, originally designed for the 10" wheel.
I hope this makes sense. The bigger the wheel the more it screws up the intended suspension geometry.

vrooom

Original Poster:

3,763 posts

274 months

Monday 2nd February 2004
quotequote all

I would gone for 10" wheels setup if it wasnt for my soon to be 4 pot brakes setup.

Jay

Cooperman

4,428 posts

257 months

Monday 2nd February 2004
quotequote all
I've always wondered about the benefits against cost of the 4-pot calipers.
When driving a Mini really hard the limiting factor always seems to be brake pad efficiency and brake fluid boiling.
I run AP600 brake fluid and carbon-metallic pads with Cooper 'S' 7.5" solid discs and don't ever have a problem. The pedal feel is always good, too.
With EBC 'Green' pads I can easily get a lot of fade on demanding roads, whilst I have boiled 'Dot 4' fluid.
It would be interesting to try a 4-pot braked Mini with big wheels against a Cooper 'S' braked one with 10" wheels on a very twisty bit of road. The question is, would the better handling and road-holding with the 10" wheels beat the presumably better braking performance, but slower speed through the corners, of a 12" or 13" wheel car, assuming they both had the same pad meterial and brake fluid.

Dodgy Dave

810 posts

258 months

Friday 6th February 2004
quotequote all
I was always under the impression that you do get more outright grip with 13's but you suffer stability and the car tends to tram line.
Oh and u knacker ur bearings allot faster

Plotloss

67,280 posts

277 months

Friday 6th February 2004
quotequote all
There were a set of 3 (annoyingly) compomotive split rims for sale somewhere last week. They were 8x13's

Cant imagine the bearing wear but a cracking looking wheel on such a small car...

Dodgy Dave

810 posts

258 months

Friday 6th February 2004
quotequote all
Oh and i can tell u peter as we once disscussed before with chris
That my car stops VERY quickly with the iron four pots vented and grooved disks with dot 5.1 fluid

Plotloss

67,280 posts

277 months

Friday 6th February 2004
quotequote all
iron 4 pots?

They off the metro?

I am currently stripping a full set and replacing the discs and pads with pagid items, hoped they would be good!

Dodgy Dave

810 posts

258 months

Friday 6th February 2004
quotequote all
Yeah i think they were orginaly from a metro but have been converted for minis.
But they do have 3 bleed points where the metro ones have two i think.
They were the ones from mini speed

Have heard good things about the pagid disks, dont know on the pads.
Will be interested to hear what u think of them when its all up and running

>> Edited by Dodgy Dave on Friday 6th February 13:32

Mr2Mike

20,143 posts

262 months

Saturday 7th February 2004
quotequote all
13" wheel's and the extremely heavy Metro four pot calipers must give a huge increase in unsprung weight which is never going to improve the handling on a car as light as a mini.

Dave40

2 posts

249 months

Saturday 28th February 2004
quotequote all
Hi Guys,

I've been musing on the wheel size v. grip issue for some time now. I'm going the Metro caliper route so it's got to be 12 or 13 inch. I'm not keen on anything which involves any body modding so that narrows the choice to 12 inch with 165/60s. The new Minilight Mk2 comes in 5x12 or 6x12 Big Deep, or Ultralight are available in 5x12 or 5.5x12. If the 6x12 produce the most vertical tyre sidewall then these should be the best choice, but would we be getting into body/suspension modding territory or at least some pretty wide arches. What do you think?

S Works

10,166 posts

257 months

Saturday 28th February 2004
quotequote all
My advice, don't go down the 13's route unless you only want them for show.


- 10's for the best classic/old skool look
- 12's for all round best performance
- 13's for looks only

Have had Coopers on 10's, 12's and 13's and by far the best fun are on the 12's with good boots. Much sharper handling, doesn't tramline and handbrake turns are cleaner

All the best!

Dave40

2 posts

249 months

Saturday 28th February 2004
quotequote all
The consensus seems to 12 inch. Just leaves the width to be sorted. I keep hearing that Falcon tyres are a good alround bet for the price.

Cooperman1

116 posts

250 months

Sunday 29th February 2004
quotequote all
Hi Dave,
I think you mean 'Falken'. IIRV Falcon was a re-mould brand from a few years ago.
The best size with a 12" wheel will be a 165x60.
The Yokohama range are slightly better than Falken, but more expensive. With the Falkens you may be disappointed at first as they seem to take a long time to reach their optimum performance and seem a bit vague until fully scrubbed-in.
For pressures try 32 - 33 psi all round. Don't set the dampers too hard either for normal fast road use.