hey fellas probably a silly question but i was wondering if the law actually says no you may not have a 13" wheel on the front and a 14" wheel on the back?
different sized wheels
Started by
_uglybob_
, Oct 07 2006 05:33 PM
18 replies to this topic
#2
rodomo
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Posted 07 October 2006 - 06:42 PM
My understanding of the Vic. RWC laws are no, unless the car was built like that e.g. Econovan with duel rear wheels and I have seen a Porche with 2 different size rims. I am pretty sure you couls have it engineered though.
#3
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Posted 07 October 2006 - 08:07 PM
Wasnt there an article posted on here about the factory turbo UC hatch as supplied with dealer options......did it have 13's on front and 14s rear?
#4
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Posted 07 October 2006 - 08:09 PM
It wasn't factory, it was dealer optioned. And yes 13" front, 14" rear.
#5
_uglybob_
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Posted 07 October 2006 - 08:25 PM
ok so you wouldt recomend it in WA? the main reason is so that i can get wide tyres on the back with out looking in every dark corner for a decent 13" every other month when the tyres become bald..
#6
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Posted 08 October 2006 - 02:16 PM
I think anybody would be very unlucky to be defected for different diameter rims front and rear. I'm not saying the law should be deliberately broken, but I'm not 100% sure that there is ANYTHING in Vic Roads website that says mixing diameters is not legal.
#7
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Posted 08 October 2006 - 03:33 PM
Hi guys.
I was informed by the WA Dept. of Planning and Infrastruture that all vehicle modification are governed by the national code of practice for light vehicle construciton and modification. There was a link to the document on their website (www.dpi.wa.gov.au).
"Section LS tyres, rims, suspension and steering" states under modifcations without certification that "All rims fitted to a front axle OR a rear axle must be of the same diameter, offset, width and mounting configuration (except for spare wheels used in an emergency situation)".
To me this means that front and rears can be different, as long as the 2 front are the same and the 2 rear are the same.
There is a lot of info in this document dealing with allowable modifications, maximum wheel and tyre sizes, max rim widths and different aspect ratios for front and rear. Its worth a read. If there is no link on the DPI website, try a google search.
I was informed by the WA Dept. of Planning and Infrastruture that all vehicle modification are governed by the national code of practice for light vehicle construciton and modification. There was a link to the document on their website (www.dpi.wa.gov.au).
"Section LS tyres, rims, suspension and steering" states under modifcations without certification that "All rims fitted to a front axle OR a rear axle must be of the same diameter, offset, width and mounting configuration (except for spare wheels used in an emergency situation)".
To me this means that front and rears can be different, as long as the 2 front are the same and the 2 rear are the same.
There is a lot of info in this document dealing with allowable modifications, maximum wheel and tyre sizes, max rim widths and different aspect ratios for front and rear. Its worth a read. If there is no link on the DPI website, try a google search.
#8
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Posted 08 October 2006 - 05:48 PM
I imagine the reg is that the wheels must be the same size and construction on both sides of the axle or implied axle line(twas illegal to have crossply and radial on the same axle).......so as cornering performance would be the same in both directions and so that the vehicle would track straight etc as well as being able to stop in a straight line. Obviously this is not an issue on heavier vehicles , so why not with cars. There are regs saying you can only go oversize by so many inches in each direction?, and this would determine how much bigger one could have the wheels on different axles.
At present the focus appears to be on the size of the rims and not the overall diameter of the tyres? .........can achieve the same change in ride height by going to a taller tyre.
At present the focus appears to be on the size of the rims and not the overall diameter of the tyres? .........can achieve the same change in ride height by going to a taller tyre.
#9
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Posted 09 October 2006 - 10:05 PM
thats awsome thanks alot for the comprehensive feed back fellas, much appreciated. ill go for 14's on the back then and 13's on the front since i only want 205's on the front and theyr apparantl not to hard to come by.
cheers again guys
ben
cheers again guys
ben
#10
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Posted 10 October 2006 - 01:00 PM
Wheel and tyre combinations are as simple as:
1. The over all diameter isn't increased by more than 15mm. This allows for different size rims from front to rear given the tyre profile allows the over all diameter to remain within 15mm.
2. The track measurment isn't increased by more than 26mm (1 inch)
3. The tyre and wheel combination doesn't foul any part of the steering, suspension or body on any of its operation.
A good book to get is the NJOY universal tyre fitment guide. Lots of good info in there..It has most specs on most models.
Hope this helps.
1. The over all diameter isn't increased by more than 15mm. This allows for different size rims from front to rear given the tyre profile allows the over all diameter to remain within 15mm.
2. The track measurment isn't increased by more than 26mm (1 inch)
3. The tyre and wheel combination doesn't foul any part of the steering, suspension or body on any of its operation.
A good book to get is the NJOY universal tyre fitment guide. Lots of good info in there..It has most specs on most models.
Hope this helps.
#11
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Posted 10 October 2006 - 02:06 PM
thanks for that ^ ,redslur......15mm change in diameter, is this +/_15mm, can be smaller too, doesnt leave much room for variations, how do they specify the original diameter of the tyre?Wheel and tyre combinations are as simple as:
1. The over all diameter isn't increased by more than 15mm. This allows for different size rims from front to rear given the tyre profile allows the over all diameter to remain within 15mm.
2. The track measurment isn't increased by more than 26mm (1 inch)
3. The tyre and wheel combination doesn't foul any part of the steering, suspension or body on any of its operation.
A good book to get is the NJOY universal tyre fitment guide. Lots of good info in there..It has most specs on most models.
Hope this helps.
Go to a tyre place and for a stock torrie they may fit a set of 185/70/13, 589mm diameter or a 185/75/13 608mm which I believe is close to the original in size, difference = 19mm, is the 185/70/13 illegal?
Edited by devilsadvocate, 10 October 2006 - 02:07 PM.
#12
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Posted 10 October 2006 - 05:48 PM
a tyre guy once told me ( and for good safety reasons) you CANT have lower profile rear tyres than front tyres.....just not sure if it means 60's front = at least 60's on the rear or rears cant be physically smaller in the sidewalls....go figure
#13
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Posted 10 October 2006 - 05:58 PM
^^ Good point. Profile is a percentage of tyre width, I'm guessing the safety aspect would be more to do with actual sidewall heights.
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Posted 10 October 2006 - 06:22 PM
Redslur, throw the NJOY book in the bin. That book has so many mistakes it isn't funny.
devilsadvocate, the regs state that the overall diameter must not be more than 15 mm larger that the largest tyre optioned for that vehicle, model or series. So for an LH - UC, the largest optioned tyre is the DR70H14 ( optioned to the L34 and A9X ) at 625 MM. Therefore you can go to a 640 MM diameter tyre. Anything bigger possibly needs to be certified. Previously, the regs atated if you exceeded that margin, the speedo needed to checked for accuracy.
revmaniac, what a load of crap. I know of at least 30 vehicles that have a smaller profile tyre on the rear from the factory, including the VE HSV barges. Safety reasons, my arse!
devilsadvocate, the regs state that the overall diameter must not be more than 15 mm larger that the largest tyre optioned for that vehicle, model or series. So for an LH - UC, the largest optioned tyre is the DR70H14 ( optioned to the L34 and A9X ) at 625 MM. Therefore you can go to a 640 MM diameter tyre. Anything bigger possibly needs to be certified. Previously, the regs atated if you exceeded that margin, the speedo needed to checked for accuracy.
revmaniac, what a load of crap. I know of at least 30 vehicles that have a smaller profile tyre on the rear from the factory, including the VE HSV barges. Safety reasons, my arse!
#15
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Posted 10 October 2006 - 08:11 PM
i wanna run 16s on the front and 17s on the back (yes its going to be engineered with the rest of the car)
(F) 205/40-16 ® 255/40-17
would this be all good and its going to be engineered
(F) 205/40-16 ® 255/40-17
would this be all good and its going to be engineered
#16
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Posted 11 October 2006 - 08:26 AM
There are several options available for the LH/LX range. You need to do your homework.
Generally the allowable increase/decrease is taken from the tyre placard found in the glove box lid. Specific to that vehicle.
A good tyre shop should be able to advise you accordingly. I failed to mention that you can decrease the diameter by up to 26mm.
As far as profile differences go, allowable limit is 10% aspect ratio variation from front to rear. I.e a 45 profile front, 50 profile rear on similar width tyres.
Generally the allowable increase/decrease is taken from the tyre placard found in the glove box lid. Specific to that vehicle.
A good tyre shop should be able to advise you accordingly. I failed to mention that you can decrease the diameter by up to 26mm.
As far as profile differences go, allowable limit is 10% aspect ratio variation from front to rear. I.e a 45 profile front, 50 profile rear on similar width tyres.
Edited by Redslur, 11 October 2006 - 08:27 AM.
#17
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Posted 11 October 2006 - 06:46 PM
Where is that stated?As far as profile differences go, allowable limit is 10% aspect ratio variation from front to rear. I.e a 45 profile front, 50 profile rear on similar width tyres.
#18
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Posted 12 October 2006 - 02:44 PM
#19
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Posted 12 October 2006 - 07:22 PM
A 45 and 55 profile tyres combo is legal, by what you posted it appeared that wasn't the case. The good news is I can legally have 9" rims front and rear on my panelvan.
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