What wheels and tyres are people using on their Hillclimb Minis.

I am curious to see if anyone is running 13s.

I am reading that a larger and wider wheel is better for traction/grip.

So that leads me to wonder why 13s would not be widely used.

Then I read an article about bigger wheel fitment which states:

"The 13-inch wheel/tyre combination brings out the worst in everything Mini suspension and brakes orientated - but to many the aesthetics far out-weigh all other considerations"

http://www.minimania.com/WHEELS___TYRES ... ation_1185


What are you running on your Hillclimb vehicle(s)?

Why aren't 13s used? (or are they).

_________________
1966 Morris Mini Minor Saloon (Dot) - 1275 Auto - Mongrel
1968 Morris Mini Van (Ivan) - 998 Auto - Mongrel
1968 Morris Mini.Matic (George) - Original
1968 Morris Mini.Matic (Charlie) - Original

13s are generally heavier, the wheel/tyre combo is quite a chunk heavier than a little 10
they are also "generally" or "Normally" outset compared to the usual 10 or 12" mini rims, causeing a fair bit of load to both wheel bearings & steering,,, not to mention the very poor scrub radius created by such an outset rim

lots of sports-sedan minis run 13 x8/9/or 10s & usually in circuit racing it`s not too much of an issue at high speeds & sweeping corners, however it`s still an issue,,, but the grip level gained seems to outweigh the scrub-radius & weight problems in such circumstance,,, in other words lots of people would have simply "put-up-with" & driven around the issues

however,,, the humble little 10" wheel/tyre combo with "decent" sticky tyres is hard to beat for tight corners & stop-start type action,,, quick respons & nimble handling are a pleasure to drive & quite fun

sure there`s less grip but you have to make you`re own mind up depending on a number of things

the power you have,,, if you have a burnt valved 850 then 13x10s with make it like a 2cyl piece of crap in the power dept, as if it isn`t bad enough with a burnt valved 850 in a hillclimb

but on the other hand,,, if you had a twin-cam turbo injected rocket ship with 300hp,,, then maybe 13x10s with super sticky rubber will be your best friend & just put up with the slight problem of scrub radius & weight & suspension/wheel brg & steering loads etc

so,,, think about the physics of your combination-->,,, your "package" ... & decide if you want nimble fun dancing easy light chuck-ability with your "medium" (whatever) power you currently have...

or do you like the tough look & stance & aggressiveness of the 13s & maybe you think you have awesome wicked power that little pissy 10s just won`t cope,,, then maybe 13s are the go

don`t forget tho,,, if you run 13X10s (or something similar) then most times the rolling circumfrence is longer & therefore gearing becomes an issue,,, it`s a bit hard to get a pissy thin little 15tooth diff pinion to cope with massive 250hp & 13x10" sticky slicks,,, & also the height of the car is raised with the bigger wheel/tyre combo

so then you start changing suspension control arm "pick-up" points on the subframe , raising the inner mounting point & shortening towers & hi-los & radically changing geometry of all your arms & steering rack positions to try to correct it all to suit the higher stance,,, blah blah blah,,, it goes on & on

so if you want to just drive your mini at hillclimbs & have fun?... or do you want the fastest mini in the world & spend the next 5 years perfecting an aggressive over-powered monster?

hope you get my point of all the variables & work required to get a 13" wheel`d car "closer" to being a great handling car or enjoy the easy & fun & cheapness & simple-ness of a 10" thing

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

I am not entering hillclimbs just at the moment, but i use 10" wheels with Yokahama A032 tyres and found them excellent for sprints. It is not like a race where the tyre wear and heat cycling can kill a 10" tyre much quicker than a larger size. You don't get the range of compounds available in larger size tyres, but then you might not need it.

I have found that the higher sidewalls on the 10" tyres result in more effective suspension than the lower profile 13" tyres but this was on two separate cars, so not a perfect comparision.

Other brands available in 10" tend to have a much stiffer sidewall than the Yokahama according to other racers, but i have not personally used them. This may work better in needing to have much less negative camber for maximum performance.

As the article says, the only available 10" slick is the Dunlop one, and this is not an ideal soft compound that would be best for hillclimbs.

To fit 13" wheels and tyres you will typically need to trim part of the front of the wheel arches to stop them rubbing and put stops on the rack to stop the rear of them rubbing the inner arch at full lock as shown in the article. I did not want to make these modifications to my car.

The other thing to consider is rotational inertia. A 13" wheel will typically have a much higher rotational inertia than a 10" wheel as well as being overall heavier. This may not make much difference depending how competitive you are, but it has to count for acceleration in a short hillclimb when it is a matter of hundredths of seconds.

But you might be able to get 13" slicks in multiple compounds that fit under the arches that give much higher grip, depending on the class you want to run in.

Yokahama also has a 13" A048 tyre available if your class restricts you to road tyres. But again from memory, these were not available in a variety of compounds like the larger sizes. The A050 is not available in 13" as far as i know. Other brands i have not looked at since i am sticking with the 10" at the moment.

_________________
the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

=".............As the article says, the only available 10" slick is the Dunlop one, and this is not an ideal soft compound that would be best for hillclimbs....."

This is certainly not true... Maybe if the statement was qualified by place and cost in the original article... But in fact there are several other options including Hoosier and Avon.... In both slick and treaded versions. American Racer make a 10 " treaded track tyre which seems a bit soft for circuit work (going by the few I've seen) but could be ideal for a hill climber.

".....To fit 13" wheels and tyres you will typically need to trim part of the front of the wheel arches to stop them rubbing and put stops on the rack to stop the rear of them rubbing the inner arch at full lock as shown in the article. ..."

Also not true... Well.. Maybe typically -but not necessarily. A mate ran 175/13s on his stock 1275LS and they fitted perfectly under ordinary LS arches. You just have to get the wheel width/offset right. While they were off the shelf wheels, the stud holes were welded and redrilled to fit a Mini.

It really depends on the class rules. If they allow slicks then there are quite a few options. Miglia wheels with US formula 500 Hoosier slicks would be interesting. If you're stuck with "road" tyres then A032s seem to be it... Unless you wanted to try some of those CR77 Dunlops they're selling in the UK these days??? Then you could try some 13" A048s as a comparison....

A008s work quite well but you can do better if you have the $$$$

Cheers, ian

We hillclimb our Nota on A032's 6x10 rear and A032 13x5.5 fronts, they are =much better that the A042's with the block tread { 50km of running to pick any temp O.o} remember that a hillclimb is requires the art of a good clean run on COLD tyres, if your happy with the grip level of what you have then just sit back and enjoy the 30 sec blast . 20 years old Perelli's are well crap, std rd tyres like the A008's will be ok but if your seriuos and have the grunt and set up to run at the pointy end then the $$ on tyres will help, the nb/c guys are mostly running Hoosiers but I have seen " Bailey's" red mini on 12in A032's. My 1275ls has done a few hillclimbs on nothing more than worn out 12 in std rd rubber @ 50psi { to redeuce the sidewall lean over} and other than having fun never noticed any difference { 1275ls @ 74bhp vs Nota @ 145 bhp - sticky tyres and bhp win all day long}

_________________
120bhp with 450kg just fun waiting to happen

We were prob. drunk when we set it up last and thought this will be a good idea

Nb mini with 10" cold Hoosiers + tight and twisty hill climb = lots of fun!

_________________
1964 Morris "Cooper S" Group Nb Racer
1965 Morris 850
ex 1967 Morris Cooper S
ex 1969 Morris Van (Rover SPI running gear)