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Legalities in Qld on rim offset?
Posted: Wed Dec 23, 2009 8:19 pm
by Winglessjet
Hello to all, Just wondering what the legalities in Qld are on changing the offset of the rim is? And is it the other edge of the tyre (sidewall) or the tread are that has to be covered by a flare? The truck is a 91 80 series and i have just scored a set of alloys but the offset is -24
Posted: Wed Dec 23, 2009 9:40 pm
by want33s
Track width* can NOT be increased. Overall width may be increased but only by a maximum of 50mm(25mm per rim).
Rim width may be increased up to a maximum of 1.3 times original width.
ALL off the tyre must be covered..
* Track width is middle of one tyre to middle of other tyre(on same axle).
Posted: Sat Dec 26, 2009 8:26 pm
by fester2au
want33s wrote:Track width* can NOT be increased. Overall width may be increased but only by a maximum of 50mm(25mm per rim).
Rim width may be increased up to a maximum of 1.3 times original width.
ALL off the tyre must be covered..
* Track width is middle of one tyre to middle of other tyre(on same axle).
That seems a little over the shop from my understanding unless it has changed in recent times. My understanding for Qld is that track (centre to centre of rims or tyres which is the same) can increase 50mm on live axles and 25mm on independant axles. Tyre width can be increased by 1.3 times or whatever the factor is but I don't recall any actual limitation on rim width as it is governed by the track allowance. Rim diameter can only be increased by plus 2 or in other words 2 inch bigger diameter.
So an 80 series with 16 x 8 zero offset rims should be able to run 16 x 8 neg 25 rims assuming the rubber stays within the guards. You would have to check the offset of the early 80 as I don't know what the offset of the 15 x 7 rims is and you have to work out the allowance if you go to a different rim width. One would expect however that your calculations caould be based on the later rims as I believe that is the other wording regarding sizes "that it is based on the largest size offered for that model"