Tyre/wheel legalities

Wheels, Suspension, Brakes & Tyres questions and answers

Moderators: timk, Stu, zombie, Andrew, -alex, miata

lucifuge
Fast Driver
Posts: 147
Joined: Sat Dec 23, 2006 1:08 pm

Tyre/wheel legalities

Postby lucifuge » Fri Mar 20, 2009 3:22 pm

Maybe this is a state-dependent question, but what are the current legalities on tyre/wheel widths?

I have an NC an am keen on a wider wheel/tyre combo than my current 17x7 stockies. I am keen on the Enkei RPF1's and while an obvious choice is 17x8, i noticed some sweet looking NC's with 17x9's. I know a 245x40x17 would stick out about 3cm from the car. Anyone know if this is a straight out no-no?

User avatar
hks_kansei
Speed Racer
Posts: 6154
Joined: Tue Feb 03, 2009 10:43 am
Vehicle: NB8A
Location: Victoria

Tyre/wheel legalities

Postby hks_kansei » Fri Mar 20, 2009 3:30 pm

yep, state dependant.

NSW uses a simple +2 and +1 system from memory, you can go 2" larger rim diameter, and 1" wider.
so on your NC it would be 19x8 max.


in Vic you are allowed to go 15mm larger rolling diameter (inc tyre)
and 25mm wider


those are just off the top of my head, so check the standards with your state's governing body beforehand.
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)

lucifuge
Fast Driver
Posts: 147
Joined: Sat Dec 23, 2006 1:08 pm

Tyre/wheel legalities

Postby lucifuge » Fri Mar 20, 2009 3:35 pm

...is getting the fenders rolled a big drama? Apparently on the NC, there's a of an issue with the rears to fit such a combo ...some panel that left as is would interfere. Do you need to be overly careful who rolls them.. which tyre company...or should they know what they're doing? Just trying to put my paranoia in perspective before I jump in.

User avatar
PUR157
Racing Driver
Posts: 967
Joined: Sun Sep 17, 2006 5:26 pm
Vehicle: Clubman
Location: Sydney, Capital of Australia
Contact:

Tyre/wheel legalities

Postby PUR157 » Fri Mar 20, 2009 3:44 pm

hks_kansei wrote:NSW uses a simple +2 and +1 system from memory, you can go 2" larger rim diameter, and 1" wider.
so on your NC it would be 19x8 max.


Is this while retaining original (or as close to as possible) rolling diameter as well?
Oneness of Man and Machine
Image

User avatar
philz
Wheel guru
Posts: 1297
Joined: Wed Jun 04, 2008 4:32 pm
Vehicle: ND - 2 GT
Location: Sydney

Tyre/wheel legalities

Postby philz » Fri Mar 20, 2009 3:56 pm

The problem with rolling if not done properly it will crack.

Some better shops out there use a heat gun, to soften up the paint, and roll the guards.

I'm not 100% sure on the NC, though I am looking at the current Hyperev mag,

And its seems they are runnuing 7-8inch, offset is minimum +40

If you want to run staggered width, say 8 at front an 9 in the back, you would also need staggered offset as well.

For 9" at the back I would be looking at +55, 8" front - maybe +45?

Integral kobe has a really nice setup with ce28, they are 17x7.5 with +33 offset all round, which is quite aggressive on the NC, and this would be my pick in offset and width..

edit: Also will you be lowering this car?

lucifuge
Fast Driver
Posts: 147
Joined: Sat Dec 23, 2006 1:08 pm

Tyre/wheel legalities

Postby lucifuge » Fri Mar 20, 2009 4:28 pm

its already lowered with the Eibach pro kit

do u have a link to pics this guys car (kobe)?

User avatar
philz
Wheel guru
Posts: 1297
Joined: Wed Jun 04, 2008 4:32 pm
Vehicle: ND - 2 GT
Location: Sydney

Tyre/wheel legalities

Postby philz » Fri Mar 20, 2009 4:35 pm

Ahh I see.

Actually what I wrote was wrong.. it's actually front: 17x7.5 +33, rear: 17x8.5 +40
CE28:
Image


This is the same car, but it's got re30's, though it's 17x8.5 all round: F:+47, R:+40

Image

Image

User avatar
StanTheMan
Forum legend
Posts: 6824
Joined: Thu Apr 24, 2003 11:00 am
Vehicle: NA6
Location: Balgowlah

Tyre/wheel legalities

Postby StanTheMan » Fri Mar 20, 2009 4:37 pm

what state are you in lucifudge?
Satans Ride called F33nix the resurrected NA6

lucifuge
Fast Driver
Posts: 147
Joined: Sat Dec 23, 2006 1:08 pm

Tyre/wheel legalities

Postby lucifuge » Fri Mar 20, 2009 4:39 pm

ACT

User avatar
StanTheMan
Forum legend
Posts: 6824
Joined: Thu Apr 24, 2003 11:00 am
Vehicle: NA6
Location: Balgowlah

Tyre/wheel legalities

Postby StanTheMan » Fri Mar 20, 2009 4:48 pm

sorry don't know my way around ACT wheels & tyres legalities.....good chance it will be the same as NSW?
Satans Ride called F33nix the resurrected NA6

User avatar
hks_kansei
Speed Racer
Posts: 6154
Joined: Tue Feb 03, 2009 10:43 am
Vehicle: NB8A
Location: Victoria

Tyre/wheel legalities

Postby hks_kansei » Fri Mar 20, 2009 5:06 pm

PUR157 wrote:Is this while retaining original (or as close to as possible) rolling diameter as well?



I cant really say, but I would presume there is also a regulation to keep it within X%
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)

User avatar
bruce
Speed Racer
Posts: 7708
Joined: Fri Apr 25, 2003 11:00 am
Vehicle: NA8 - Turbo
Location: Victoria
Contact:

Tyre/wheel legalities

Postby bruce » Fri Mar 20, 2009 5:20 pm

philz wrote:Image


Its got a beard and goatees.

lucifuge
Fast Driver
Posts: 147
Joined: Sat Dec 23, 2006 1:08 pm

Tyre/wheel legalities

Postby lucifuge » Fri Mar 20, 2009 5:25 pm

hmmm don't know, maybe ACT's ruling is same as NSW. deserves a check.

User avatar
philz
Wheel guru
Posts: 1297
Joined: Wed Jun 04, 2008 4:32 pm
Vehicle: ND - 2 GT
Location: Sydney

Tyre/wheel legalities

Postby philz » Fri Mar 20, 2009 5:38 pm

bruce wrote:Its got a beard and goatees.


and sideburns

User avatar
StanTheMan
Forum legend
Posts: 6824
Joined: Thu Apr 24, 2003 11:00 am
Vehicle: NA6
Location: Balgowlah

Tyre/wheel legalities

Postby StanTheMan » Fri Mar 20, 2009 6:23 pm

If its the same as NSW ......

increase of 25mm in width
a decrease of offset of 12.5 mm (per rim)
size of wheel does not matter as long as the total height or combination of wheel & tyre is not more than 15mm higher or lower than standard.

of course you can always get it engineered......
http://www.rta.nsw.gov.au/registration/ ... 9_rev4.pdf
Satans Ride called F33nix the resurrected NA6


Return to “MX5 Wheels, Suspension, Brakes & Tyres”

Who is online

Users browsing this forum: No registered users and 402 guests