Backspacing question.

[AJLFJ80]

On my 91 I ran Eagle 589s 15x8 with 3.25" backspacing with 35x12.50 BFG MTs. I think it was ideal. On my 94 I had to run 16" rims to clean the brakes so I ran 3 5/8" backspacing 16x8 MT Classic 2s with 315/75/15 Toyo MTs. On a 91 there is no reason to buy rims that would need spacers because there are plenty of decent 15" wheels available.

Awesome. I just bought 15x8s with 3.75" backspacing with 33x12.5 tires. The only thing I'm debating right now is whether not to spend the extra ~$160 getting wheel spacers. I'm putting in 30mm coil spacers all around as well. It seems like the consensus is leaning towards "no spacers needed", which is good, I'd rather not spend the extra ~$160

 

[d0ubledown]

more backspace = more chance of rubbing frame & suspension. more backspace moves the wheel/tire inbound. usually, backspace on a stock wheel is positive offset. meaning a 7" wheel will have a center line of 3.5". 7" wheels are usually about 4" or more backspace, especially oem so that way they dont stick out too much, to clear fenders and body panels. aftermarket wheels are usually biased towards negative offset (smaller backspace) meaning they'll usually make the wheel stick out more, to clear suspension/brake components, but might interefere with body or fender, depending on the wheel/tire combo, and the amount of room available.



spacers are OK. not as good as proper wheels with desired backspace to achieve clearance though..and there are good and bad quality spacers. 91/92s had 15" wheels, therefore the 93-97 owners that wanted to run 15s needed spacers so the wheels can clear the calipers.

but yes, a 33/12.5/15 on a 3.75" backspace should be fine if its on a 7 or 8" wheel.

 

[AJLFJ80]

This is all good s***, thanks guys.

 

[Tools R Us]

... 7" wheels are usually about 4" or more backspace, especially oem so that way they dont stick out too much, ...

It may have something to do with fit, but the main reason for increasing backspace is strength. The tire center line, centered over the bearings is the strongest, most durable setup. Also moving the tire center line closer to the knuckle rotation point reduces scrub radius improving steering/handling.

...and there are good and bad quality spacers. ...

I have seen some way cool custom type spacers, but among the "normal type" all that I have seen lately looked the same, like they came out of the same machine. If you know of a vendor selling bad spacers please out them so others wont make that mistake!

 

[alkaline747trio]

Don't spend a penny on spacers until you have you're tires mounted on the wheels and under the rig. Those spacers could feasibly stick your tires out too far that the scrub radius causes issues and the tire rubs on the fenders/wheel wells.

 

[ravencr]

I've got a question...

I have a '97 LX450 with stock wheels, and I'm wondering if I can run 3.5" 16.5x10" wheels with no problems with 37" tires? Stock is 4.5" backspacing, right, so I'd be moving the tires out 1" or would it be more than 1" given the extra wheel width?

Chris