backspace help

[450ryder]

i searched this forum and google to avail... im looking at new wheels for my truck and they have a weird backspace number system. can somebody please help me understand this? i want 22" that stick out about 1-3"

http://www.akuza.com/rwd_aka_455.htm

edit: i think i have it figured out. +18 offset 5.96 backspace will that fit?

[TIsTAN]

try this tool, but not sure how correct it is.
http://www.1010tires.com/WheelOffsetCalculator.asp

25.4mm is equal to one inch.

[NorCal 4x4]

Originally Posted by 450ryder

i searched this forum and google to avail... im looking at new wheels for my truck and they have a weird backspace number system. can somebody please help me understand this? i want 22" that stick out about 1-3"

http://www.akuza.com/rwd_aka_455.htm

edit: i think i have it figured out. +18 offset 5.96 backspace will that fit?

Our bolt pattern is 6 on 5.5" or 6 on 139.7 mm. So it's the only one with a chance of fitting. It will stick in towards your steering knuckle an extra half an inch compared to the stock 18s, (could be an issue, check to see how much clearance you have now with a scrap of wood and measure). Since they are 9.5" wide and you'd stick in an extra 1/2", that means they would stick out 1" more, (plus any additional because of a wider tire). You might need to do the pinch weld mod for rubbing when you turn the steering wheel to full lock.

What tires are you planning for?

[titan_1965]

Check with your local wheel shop

[450ryder]

i have 35" toyo MTs on 17"MWK wheels right now. the 455 is the style i was going to go with and 37" kumho's. will i need wheel spacers possibly?

[NorCal 4x4]

Originally Posted by 450ryder

i have 35" toyo MTs on 17"MWK wheels right now. the 455 is the style i was going to go with and 37" kumho's. will i need wheel spacers possibly?

I think a big thick spacer with the Kumho KL71 on a rim with a 6" backspacing. The 37" KL71 is 13.5" wide!

To have an idea of how thick a spacer you'd need, a couple of questions.
What model, width, and offset or backspacing are your current MWK 17s?
How much clearance do you have with them, to your Fab Tech spindles?
[I assume the FT spindles give you even less clearance than the stock steering knuckle, but only because the CST 4" spindles do].

Also, do you have room for a 36.8" diameter tire?
Your current tires are 34.8" diameter, so the 36.8s will be 1" more on each side of your axles. So if you have more than an inch to the front of each tire, and more than an inch to the rear of each tire, and above, and remember even for street only use, they will be cycling pretty much straight up and down, a few inches, so this clearance will be needed in that path as well.

I think you will need glass or the Ionic Dynamics fiber reinforced plastic fender for the Kumho 37s, even for street only.

[450ryder]

i will have 9" of lift when these are installed so the tires should clear. it is snowing right now but soon as it stops i will check out clearance of the spindle.
my wheels now are MWK m25 i dont know what the backspace is or anything else about them, they were on the truck when i bought it

[NorCal 4x4]

Originally Posted by 450ryder

i will have 9" of lift when these are installed so the tires should clear. it is snowing right now but soon as it stops i will check out clearance of the spindle.
my wheels now are MWK m25 i dont know what the backspace is or anything else about them, they were on the truck when i bought it

Depending on which of these you have and your spindle to tire/rim measurement, will help determine if you clear.

MKW M25
Size .......... Bolt Pattern ...... Offset ...... Backspace ...... Hub Bore
17 x 8 ....... 6X139 ................. 0 ........... 4.50" .............. 78.1
17 x 8 ....... 6X139 ................ 25 .......... 5.48" ............. 100.3
17 x 8 ....... 6X139 ................. 0 ........... 4.50" ............. 109.8

Akuza with 6" proposed backspacing to the second MWK25 is 1/2" closer to the spindle.
Akuza with 6" proposed backspacing to the 1st and 3rd MWK25 is 1.5" closer to the spindle.

Sometimes, (maybe always), the nominal rim size and offset is stamped/cast into the rear side of the wheel. So if you have an inch clearance and your rims states 17 x 8 0, or similar, you can't do it without a wheel spacer, (but almost everyone says "Don't Use A Wheel Spacer").

Also, the tire issue.
Currently you're running the 35x12.5x17 on your 8" wide MKW m25s. They're 13.2" wide on the spec sheet's measuring 10" rim, and should be roughly about 12.4" wide on your 8" rims. The 37" Kumho KL71 on your proposed rims will be an inch wider, at about 13.5". Half an inch to the inside and half an inch to the outside of the rim.

So, best case, your current rims are the second ones I listed above, and you have a hypothetical 1" of current clearance, your new backspacing will put the rim 1/2" closer to the spindle, and the tires are 1/2" wider to each side, so you're rubbing, and need a wheel spacer of maybe an inch thick, or a different rim.

Worst case, your current rims are the first or third rims I listed with 4.5" backspacing, and you only have a hypothetical 1" of current clearance. In this case you would need a 2" wheel spacer, if they make them.

If you can make these fit and don't off road it would be an interesting/different look. But these rims don't seem like they would hold up to much, even a curb.

[450ryder]

i dont offroad it but i tow a little. i really like the rockstar wheels but i want somthing thats chrome with black in 50:50 proportion and everybody has the rockstars. i want to be different. this is the style. anything like this that may fit?

[IMG][/IMG]

[NorCal 4x4]

Originally Posted by 450ryder

i dont offroad it but i tow a little. i really like the rockstar wheels but i want somthing thats chrome with black in 50:50 proportion and everybody has the rockstars. i want to be different. this is the style. anything like this that may fit?

Probably look for something like that in all chrome, and have a powder coater or automotive paint shop finish the alternate spokes. Much better chance of finding one you like and that fits, than if you limit yourself to that color scheme.

As far as rim width, probably a 8.5" or 9" rim, but you need to report back on your current clearances, like tire to the spindle, and to the fenders in the front and behind each tire.

[TravisDTD]

The Hotwheels D-backs come in a 22x11 with a -25mm Offset. That would give you the look you are looking for. A 22x11 with a -25 offset would stick out about 3.5" further than your stock wheels. you should be able to run your 37" on those nicely, you probably will still need to do the pinch weld mod.