Wheel Offset Calculator

http://www.1010tires.com/WheelOffsetCalculator.asp

Slick. It wouldn't be hard to extend it to show tire size impact as well. Hmm, I think I have something to do over the weekend.

Anyone know of one that translates backspacing into offset and vice versa? The one at CCW's website never works for me.

back spacing is just the measurement from the back of the wheel to the flange...

offset is the distance from the center of the wheel to the flange.

25.4mm to an inch, grab a calculator...

Offset is positive if the backspacing is greater then half the rim width (if the wheel flange is past the half way point towards the outside of the wheel) so

25.4(backspacing-width/2)=offset (backspacing in inches, offset in mm)

or

offset/25.4 + width/2=backspacing.

Why does this forum always keep you from starting a new line? It always runs my paragraphs together unless I use HTML code to start a new line

Backspacing = (wheel width/2)+(offset/25.4)

Note that wheel width is not necessarily "wheel width". The width of the lip needs to be added in there, and I think that typically adds an inch of total width.

Yeah, I was thinking about that.... I went to double check by looking up some pictures, and it showed offset as wheel flange to bead lip, but I didn't see one for backspacing so I wasn't sure if they measured from the lip as well... But its as close as any online calculator will get you considering that the lip of the rim is probably not a standard measurement...

I swear, the filter at work is so damn goofy. It's blocking the link for the offset calculator as a "VoomTube" object. Were they hacked or something?

RedS13Coupe wrote: Yeah, I was thinking about that.... I went to double check by looking up some pictures, and it showed offset as wheel flange to bead lip, but I didn't see one for backspacing so I wasn't sure if they measured from the lip as well... But its as close as any online calculator will get you considering that the lip of the rim is probably not a standard measurement...

Offset is the difference between the centerline and the flange. Lips or no lips makes no difference. Wheel width is measured from the inside of the lips, so you have to take them into account with backspace.

The calculator above dodges the issue by simply showing the difference between two wheels. It's probably fair to say that the lips are going to be pretty similar in size. But since most of us run tires on our wheels, it's of limited use to know wheel clearance anyhow.

lol. yeah I guess its a good point that lip doesn't make a difference as the center between the two bead seats is the same as the center between the two lips

My point was that with out accounting for the specific measurement of the rim you can only approximately convert from backspacing to offset, and that two different rims could technically have the same backspacing but different offsets (though they would be pretty damn close...)

I have always said that tires are for the weak anyways

Somebody say tire size impact as well?

http://www.rims-n-tires.com/rt_specs.jsp

I love this calculator!

Perfect, thank you!

RedS13Coupe wrote: Why does this forum always keep you from starting a new line? It always runs my paragraphs together unless I use HTML code to start a new line

It builds charachter. I'm pretty sure that there is a random function that just messes with me embedded somewhere in the code.

Damn, my secret is out:

 if request.user == 'DILYSI Dave':  
      do_weird_stuff(request.user)

Tim Baxter wrote: Damn, my secret is out: if request.user == 'DILYSI Dave': do_weird_stuff(request.user)

LOL.