Ok guys I needs some help understanding this whole backspacing and offset issue with wheels for my truck. I currently have the moto metal 951's, 17X9 with 4.53 backspacing and an offset of -12. I just got new tires today and went with the Toyo MT 295's and they still rub a bit...I wanted the 35's but there was no way they would fit with these wheels. I know plenty of people are running 35's with only the leveling kit. So my question is what do I need for wheels to run the bigger tires? More offset, less offset, more backspacing, less backspacing? I got little help from the tire folks and my searches here have resulted in some seemingly contradicting information. I am looking at the american racing Thugs wheels and they come in: an offset of 15 w/ 5 3/8 backspacing or -6 offset with 4 1/2 backspacing. Any improvement here? If not, what are some good offset/backspace number to look for. Thanks for any help.

 

The proper back spacing is over 6" and the offset is 25mm. Moto metals do not have a rim that is exactly the right fit for our trucks. I put on eagle alloys 0836 with 25mm offset. Fits perfect

Kevin

 

You definately want 6" back spacing..

 

Shane, how much backspace and offset do the Mako's have?

 

A couple points I'd like to make:

1. Proper backspacing and offset changes with the width of the wheel. They are not constants.

2. Try to limit wheel width to 9". Anything wider typically leads to rubbing.

Refer to the following picture for an explanation of measurements. Pay particular attention to from what points rim width is measured, then compare that to where backspacing is measured from. There is a gap there. I usually estimate that gap to be 1/2", and that's usually close.

 

Im glad you chimed in Pauly, you are the local resident expert when it comes to rims

Kevin

 

Ok, that helps...so according to the diagram, how would have negative offset? Or positive? Thanks.

 

6" is what I measured..


That is very true!!! Pauly is the man..

Shane

 

Wow! I feel so loved

Offset is measure from the centerline of the wheel to the mounting surface of the wheel. If the mounting surface is outside the centerline (closer to the outside edge of the wheel) you have positive offset, and conversely if the mounting surface is inside the centerline (closer to the inside edge of the wheel) you have negative offset. Notice that backspacing can only be positive.

 

Gotcha, thanks fellas. The stock wheels were +42 and 6.1, thanks that what I read somewhere here??? and I went to -12 and 4.53, no wonder my combo rides outside the fenders. Again, many thanks.

 

Kevin, What size tires/20s did you end up w/?