Offset & custom wheels theory - right or wrong ?

[helen07]

I have read the standard 90 wheels are +15 to +30 offset depending on who wrote it .
Everyone accepts the 80 series 16x8 wheels have a zero offset and fit the 90 series well with the advantage of a wider stance and better look .

My theory , or question , whichever way you choose to look at it is this -

The 16x8 is one inch wider than standard (16x7) on its own , and the zero offset brings the whole wheel/tyre approx one inch closer to flush with outer wheel arch . I would guess the zero offset coupled with the wider wheel actually move the wheel an inch and a half or 38mm outwards .

If i figure this right then this should leave a shy inch of empty space formally occupied by the positive offset of the original wheel .

So the optimum wheel size for an otherwise unmodified 90 series should be 16x9 with a +25 offset .

I'm not sure i follow my own logic here but i would be grateful for opinions from anyone who understands what i'm trying to say .

 

[Paddler Ed]

I think you're sort of on the right lines.

From what I know of the 90 series (learnt whilst looking in Aus at the VZJ95 GXL spec and RZJ95 RV Spec) there were 2 different tracks offered.

Redbook says that the VZJ95 had a 1505/1510mm (f/r) track and 16x7 with 265/70R16's and the RZJ95 had 1475/1480 (f/r) and 16x6 with 215/80R16's

With the offset, or as the American's call it the Back Space, at 0, then the hub connects to the rim at 4" if using an 80 series rim. Using the 7" 90 series rim, you get 3.5" +15mm... which is ~4" from the inside of the tyre to the hub. If running 6" 90 series rims + 30mm offset gives you 3" + 30mm or ~4" and a bit.

The problem that you may find is that running an ET0 rim is that the inside may foul on suspension components etc, rather than necessarily protrude outside of the arches.

HTH helps; I have to say this is based on logic and information rather than personal experience!

 

[helen07]

Thanks Ed , i wont pretend to understand more than i do , but in reply to "fouling on suspension" wouldn't a +25 offset only be a very slight difference from where the original wheel sat ?

 

[helen07]

OK i will try again .

The true offset on OEM 90 wheels is +15
The 80 series alloy is 8 inch (203mm)
203 + 15 = 218
A 9 inch wheel measures 228mm

So if an 80 series wheel can be ran on a 90 with a 10mm spacer (which should bring it absolutely flush with the wheel arch , Euro Law allows 30mm protrusion i believe)n then it stands to reason a 16x9 wheel with a +15 offset will fit .

Question is will an 80 series wheel with a 10mm spacer fit the 90 without the need for a lift ?

Of course all this is very dependant on tyre choices but thats another can of worms !

 

[Beau]

Just thought I would let you know I am running a 9.5" width wheel, with a -15mm offset, and a 305 Tyre. This is about 5 mm from the top wishbone so is basically as close as can get. The wheels pop out from the arch only slightly, probably about 5mm...

 

[Gav Peter]

You also need to consider the size of the tyres you are going to fit... We run 80 alloys with 275/75/16 BFG ATs fitted on our Collie; they don't rub too often

If you fitted a spacer with this combination I'd say you'd be in trouble; I tried 30mm for badness once Only did one side as it was apparent it wouldnt work out well; looked good though

 

[helen07]

Just thought I would let you know I am running a 9.5" width wheel, with a -15mm offset, and a 305 Tyre. This is about 5 mm from the top wishbone so is basically as close as can get. The wheels pop out from the arch only slightly, probably about 5mm...

I assume your running this with a lift installed Beau ? Nevertheless i would glad to see a pic .

My thread may be pointless anyway as i have searched and searched for 16x9 wheels with a positive offset with no success at all , plenty of 17x9 but that sort of defeats the object because what i actually like is the doughnut look of a small wheel and big tyre .

 

[Beau]

No Lift, but I did have to reshape the front Mud flaps and grind some of the metal work behind it so that it wouldn't touch on full Lock.

Unlike most people, I am running Big 22" Wheels on my Colorado. I never go offroad so prefer this kinda look. The overall tyre diameter is 31.8" exactly!



I know it's not everyone's cup of tea, but for me being on the road 100% it works great, awesome look and still gets me through the snow!

 

[clivehorridge]

Cool! The next post will be on "lowering" suspension tips! Only joking... Lovely truck.

 

[Chris Green90]

Cool! The next post will be on "lowering" suspension tips! Only joking... Lovely truck.

There used to be a White Hilux Surf running around near us that had been lowered, body kit, big chrome alloys, blacked out windows, think it even had underbody lights and it looked excellent, much better than a RR Sport IMHO.

 

[chadr]

No Lift, but I did have to reshape the front Mud flaps and grind some of the metal work behind it so that it wouldn't touch on full Lock.

Unlike most people, I am running Big 22" Wheels on my Colorado. I never go offroad so prefer this kinda look. The overall tyre diameter is 31.8" exactly!

That diameter is pretty much the same as running 265/75 on standard alloys - which is about 31.7 inches and most people have a tiny bit of rubbing but nothing to worry about and no need to alter mudflaps etc. In your case it may be the extra width (not the diameter) that caused the rubbing.

P.S. Truck does look good with those wheels - how do they fair on potholes etc. ?

 

[helen07]

Plenty with Rangerovers go for that kind of look Beau at least you chose a better vehicle alround to modify to your own preference .

 

[Beau]

That diameter is pretty much the same as running 265/75 on standard alloys - which is about 31.7 inches and most people have a tiny bit of rubbing but nothing to worry about and no need to alter mudflaps etc. In your case it may be the extra width (not the diameter) that caused the rubbing.

P.S. Truck does look good with those wheels - how do they fair on potholes etc. ?

Yes, 305 is quite wide, but I like the look and it's very rare to get a thinner option tyre in the UK, for example 285 45 22 would probably be more suitable. For standard suspension that is as big as it will go, and my speedo is reading spot on.

Most 22" wheels run 295 30 22 tyres, but they are too small and too low of a profile. I went for the 305 40 for the higher profile mainly and better ride. Have had no pot hole damage or anything, but the roads here in Milton Keynes are genuinely quite good.

Not looking to do much more modifications with her, would like a 3" stainless exhaust with a better turbo exit, as well as a nice front mounted intercooler for a little more

 

[clivehorridge]

A mate of mine is running 22" with 30 profile and he's constantly getting pinches from going up the stony village track to his house. He must have lost 5 or 6 tyres with side-wall cuts.

I'm running 305x70x16's zero offset on my 80 and they work fine, look good, don't rub and suit the gearing on the car.

They're GG AT2's so they're on and off road friendly. Good all-round for me...

 

[Beau]

A mate of mine is running 22" with 30 profile and he's constantly getting pinches from going up the stony village track to his house. He must have lost 5 or 6 tyres with side-wall cuts.

I'm running 305x70x16's zero offset on my 80 and they work fine, look good, don't rub and suit the gearing on the car.

They're GG AT2's so they're on and off road friendly. Good all-round for me...

Thats exactly why I chose the 40 profile instead!

A bit off topic but does anyone know if the camber on the front suspension of the colorado can be adjusted. Because I have 30mm spacers and near 0 offset wheels, my track has increased a fair bit, leading to an increase in my camber angle. This has made my outside edge wear more than the inside. Wondering if it's adjustable somehow...

 

[helen07]

Thats exactly why I chose the 40 profile instead!

A bit off topic but does anyone know if the camber on the front suspension of the colorado can be adjusted. Because I have 30mm spacers and near 0 offset wheels, my track has increased a fair bit, leading to an increase in my camber angle. This has made my outside edge wear more than the inside. Wondering if it's adjustable somehow...

Personally i would just take it to kwikfit for a full wheel alignment , it might cost you £100? but thats peanuts when you consider your tyres might last twice as long .

 

[Beau]

Personally i would just take it to kwikfit for a full wheel alignment , it might cost you £100? but thats peanuts when you consider your tyres might last twice as long .

I ended up doing everything myself. I did originally take it somewhere but they had no clue what they were doing and put the steering wheel out of line. I used a string and tracked it against the back wheel and after multiple adjustments I had it dead on, along with the steering wheel. A string is as accurate as those fancy laser machines to be honest. The camber is even easier. There are only 3 settings and it comes set in the middle one. I didn't adjust this as after adjusting the toe she drove perfect.