i am thinking about putting 33x12.5 on my 05 f150. i have the leveling kit (not put on yet) and i am thinking 17x9 wheels. anyone have any suggestions or maybe what they are running as far as backspacing? i would like them to sit in the wheel well as far as possible without rubbing.

 

THe OEM wheels have 5.5 inches of backspacing. I would try to stay close to that.

 

Would a 20x9 with 6.2 inch backspacing have issues on a 06 4x2 SCrew? I myself would like to put on 295/50's

 

Those should be fine.

 

Are backspacing measurements calculated something like below?

OEM is a 7.5 wheel. Backspacing is 5.5 on the inside and leaves 2 on the outside.

An aftermarket wheel is 9. Backspacing is 6.2 which leaves 2.8 on the outside.
This wheel extended .8 further out than OEM?

Is it that simple?

Figuring further regarding the tire..
Say a 295mm width tire roughly is 11.5 inches. If it was mounted on a 9 inch rim, that would make it 1.25 over the rim each side?

Is there a max that models can handle using figures such as diameter, wheel width, backspacing etc... ?

The reason is that I want to fill the wheel well as much as I can w/o trimming and rubbing. I love the full wheel appearance but I dont want the tires to stick out further than the body.

 

Yep, it's pretty much that simple. It always helps to see trucks with different size wheel/tire combos to visualize how a given combo will look.

 

Thanks

 

I was trying to make a chart to estimate Tire/Wheel combinations that will figure how much a wheel and rubber will extend outside from original. I came up with this. Hopefully it will post.


Wandell, does this look about right?

 

I just put on 17x9 with 4.75 backspace on 33x12.5 and they stick out alot!

 

There is an error in your theory. I you have a 7.5" wheels with 5.5" on the inside, you will have 3" on the outside. All wheels measure 1" wider than what they say. By industry standard, all wheels are measured from inside the bead (ex. 7.5")("advertised width"), overall including the bead (.5" on each side), the wheel will measure 1" wider (ex. 8.5"). With this being said, Backspace is measured from the mounting surface of the wheel to the very back of the wheel including the bead. So if this is 5.5", this would leave 3" to the front (from the mounting surface to the very outside edge of the wheel.)

I used to work at a wheel manufacturer in sales and graphics, and this is correct across the board.

Hope this helps. Thanks.

 

This website will make your tire and wheel combo choices much easier. Put the stock dimensions on the left side and the desire dimensions on the right. It will show you a graphical display, raw numbers, as well as how much the tire/wheel combo will stick out over stock and fill the wheel well. Its a wonderful tool that I experimented a lot with.

http://www.bigcustomwheels.com/rt_specs.jsp

 

Thanks Street. Shows how much I know of this

NC. That is SO helpful. Thanks for the link.


BTW I see the orrer I made on my Excel chart. i put factory BS at 4.5

 

Glad I could help!

 

No Problem!