tyre question (305s)

[Zander]

Zander, you can get better deals than that locally, even on EBay!

As others have said it looks like you got mixed up between 70 and 75.

70 you can get here, I already bought off ebay locally BFG KM2 285/70R17 for $332 each tyre fitted and balanced.

75 you can only get here by importing yourself.

[millhouse]

Need to get in touch with the tyre importers via Facebook - email etc and let them know there is a market for 285/75/17 tyres

I spoke to the guys from toyo who indicated they would consider the size for aus if there was more people expressing interest

[wrench]

On the rim issue I am running a legal set of 17 x 9 rims with pos 20mm offset. Track increase is on the max legal at 50mm. Doesn't help a lot with chassis or sway bar Clearance as they only increase the BS by 1/4 inch.

[task82]

Need to get in touch with the tyre importers via Facebook - email etc and let them know there is a market for 285/75/17 tyres

I spoke to the guys from toyo who indicated they would consider the size for aus if there was more people expressing interest

What really jacks me off is how lazy manufacturers/importers are. We live in the social media age, it isn't hard to approach your consumer and get some free market research to see what the consumer is interested in. For them to say, if more people express interest then we'll do it, is just pathetic IMO.

[shmick82]

so regarding the wheels and track increase of 50mm, its not backspacing that matters (although enough backspace ie lower number, will push rim out past guard) but the offset. am I right to say an offset of +25mm equates to 50mm which is the limit, or does it work differently?

otherwise a backspace above 4.5 should be ok in the guard? I like the 98 pro comp wheels, the options are 16x8 with 4.25 or 16x8 with 5. I assume the 5 backspace will allow for less clearance, but still keep the 305's within the guard? Will the 4.25 exceed the guard by much, if at all?

[redfox355]

On the rim issue I am running a legal set of 17 x 9 rims with pos 20mm offset. Track increase is on the max legal at 50mm. Doesn't help a lot with chassis or sway bar Clearance as they only increase the BS by 1/4 inch.

Wrench, what model rims are these? Alloy or steel? Would I be right in saying the backspace is roughly 5.3 inches? What tyres are you running on them?

[SeaComms]

When you first lay eyes on this stuff it can be quite confusing!

The offset is referring to how far (in or out) the mounting surface of the wheel is away from the dead centre of the rim. So an 8in rim is actually about 9in wide in total, and if the mounting surface was smack in the middle then it would be a 0 offset rim. On the JK, the mounting surface is pushed toward the outside 45mm from the centre line of the rim, so we have a +45mm offset (on the stock 17in rims).

Track width is the measurement of the width of a vehicles wheel tracks it leaves behind in the mus as you drive off. So as to not be effected by different width tyres, the measurement is made to the centreline of wheel which means the wheel track is now directly related to our offset. So if you increase your offset from +45 to +20mm you are moving the mounting face of the wheel 25mm further in (making a deeper dish wheel) and pushing the centre line of the rim 25mm further out each side. Our track measurement now starts 25mm further out one side and finished 25mm further out the other side giving us a 50mm wider track.

The back space is simply the distance required from the rim mounting surface to the inner most lip of the rim to clear any suspension parts (or space required at the back of the rim). Remember earlier when I said an 8in rim is really 9in wide, what I mean is the section where the tyre bead mounts is 8in wide, the lip on the outer edge is 1/2 in further out so an 8in rim is total 9in wide. If this rim was a 0mm offset, the mounting face of the rim would be dead center, so we would have a 4.5in back space (1/2 of the total 9in wide rim). Change this to a +25mm offset and you have pushed the whole wheel an inch in toward the suspension, so added an inch to the backspace to be now 5.5in.

JK to be legal needs a +20mm offset wheel, and to clear suspension needs 6in or less back space (preferably 5.5in or less with wider tyres).

Hope that makes sense!

What you can do now though is have a play around with this tyre/wheel calculator as you can see the differences as you make them. www.rimsntires.com/specs.jsp

[wrench]

Redfox355, my rims are American Racing Wheels ATX series, Killer. Pos 20 offset on a 17 x 9 rim equates to 6 inch backspacing I think, whereas original Jk rims are 6.25 inch. The rims are dual stud at 5.0 and 5.5 PCD.