15x10 vs 15x8

i have 33x12.50 duratracs and have 15x10s mickey beadlocks they stick out pretty far and im wondering if i should get some 15x8s. when i trurn at full lock im rubbing some and im wondering if i should get 15x8s and if this may solve the problem im sure the offset affects this also? im just wondering with 2 inch wider wheel if it could causing it to rub, also is there an advantage of running a 15x10 wheel on a 33x12.50 that a 15x8

 

As per the goodyear website, they recommend running the 33x12.5x15's on rims 8.5-11" in width.

 

You need to look at the offset and backspacing to address the rubbing.

 

the back spacing 0f 15x10 is 3-5/8 and offset is -48

and 15x8 is 3-5/16 and offset is -30

 

The rim shouldnt be your problem. no matter what rim you use the surface of your tire is still going to be 12.5 inches wide. yeah it will be sucked in a little bit where the tire meets the rim but that is not where you are going to be rubbing at. youre rubbing where the tire is the widest and that is at the top, or outer edges of the tire. sure your sidewall sticks out a little more than the outer edge of the tire but the sidewall is not a place that i have seen a tire rub.

Rim width to tire width is solely for the purpose of bead control and with beadlocks he is not in any danger of this so running 8 instead of 8.5 wont matter. in the end you could go to 8 inch rims but it isnt going to help your rubbing issues one bit.

you can try to suck your tires inward or outward but you may just end up rubbing on a different part of the tire in a different place.

information needed is where exactly is the tire hitting on the truck and what part of the tire?

 

I'm thinking the backspacing is too low, pushing your tire out too far, causing the turning "arc" to be wider, leading to the rubbing.

4.0-4.5" BS is ideal for the first gens.

 

If the wheels have the same backspacing, then the outer edge of the 10" wide rim sticks out 2" further than the 8" wide rim. The tires are centered on the rim, so if he ran this same tire combo on an 8" wide rim (which I wouldn't recommend because the tires are too wide) , the tread of the tire would actually sit further in, by an inch.

 

15x8 would make the tire taller and not as wide, right?

 

not sure we understand backspacing....



B is the backspacing measurement. it doesnt matter if this rim is 15x8 or 15x10. if it has 4 inches of BS then the distance from where the rim meshes with the stud is 4 inches. no matter what the width of your rim. "B" is what ever the backspacing says it is. the width of your rim does not affect it. going to a skinnier rim with the same BS is not going to get him anywhere. all it is going to do is suck his sidewalls in a couple inches. its not going to change the width of his tread on the circumference of the tire.

we really need to know the spot that he is rubbing on the vehicle and the tire to adequately find a solution to this.

mine was rubbing and i took off my spacers...this plus cutting my cab mounts helped.

Edit:

the change in height would be unnoticed... it will NOT make the tire skinnier...the tread is always going to be as wide as it is however your side wall will change a little.

 

on a pre 2001, a good backspace on a 15" wheel is 3.75" although the smaller ones are still doable...

is your truck lifted or stock suspension? if stock suspension a 33x12.5 will rub regardless of backspace...

if you have a lift, a 15x8 will look a little better and be easier to resell later if you decide to swap out wheels...

if lifted and still rubbing, find out where you have the rub... likely with the backspace that far out, you are rubbing on pinch weld...

you can pound that down with metal mallet and have your casters set at 1.5 degrees forward... if that then makes the outer sidewall rub on the front valence, try 1.2 degrees forward...

it typically ends up being a trial and error process as every truck sits differently...

 

I understand backspacing just fine.

As an example of what of was saying earlier, picture a truck with the "hawaii" look, say a tire with a 12" tread on a 16" wide wheel. The bead seat and sidewall will be stretched 2" on each side, so the tread will sit 2" in from the rim on both the inside and outside of the rim.

Say we switch to a 12" wide rim. Now the tread is aligned with both the inside and outside bead seat of the rim.

If rim A has the same backspacing as rim B, then the tire tread, using Rim B, now sits 2" further in on the truck, correct?

 

WTF?

Hawaii Look? someone show me please...

 

ok.... I think that you have an understanding of part of backspacing. Keith is on target. "B" is the backspacing, you are correct. What you forgot to take into account was total overall width. On a 10" wide wheel with 4" of backspacing, you still have 6" of wheel that can potentially rub on cab mounts, bumpers, etc. By having a 8" wheel with 4" of backspacing, you lose 2" of wheel width that could potentially give you all of these problems. Between the two, I would choose the 8" wheel. If it were mine, I'd look for a 8.5" wheel with an offset of -12 (around 3.75" bs) which should give you the width requirements to get the most even wear out of the tires, while avoiding the majority of your rub issues... hope this information helps

 

I just threw up in my mouth a little keith... it's like hellaflush, truck-style

 

hope there are safety beads on those wheels!

 

You are NOT understanding that it does not matter how wide the rim is! all that is going to do is suck the sidewall in....if the backspacing is the same then it doesnt matter if my rim is 8 10 or 12 inches wide. all that is going to do is suck the sidewall in not bring the whole tire in.

Picture this...you have a tire on a 12 inch rim on a truck and it has 4 inch BS.... you are now magically able to make the rim suck inward toward the vehicle 2 inches(keep in mind the BS is staying the same). only the distance from the lugs to the outer part of the rim is changing (Distance C in pic). while magically sucking the rim in all you are doing is bringing the sidewall in NOT changing the position or width of the tread on the outer circumference of the tire.

Do we understand now?

to clarify with a 15x8 and 15x10 rim with the same BS- only distance C changed NOT distance B. all you are doing is sucking the sidewall in. your not magically making the tread width any differrent

 

thats not my truck but jlees. but he had the same problem and has a 10inch wheel. im rubbing where the blue and green line is at.

 

getting a lower BS like mike said may help you there but ultimately your only going to get a little bit of help from it. at full turn you may be able to alleviate the problem but the minute you hit a curb or bump or something it is going to hit it. dont waste your money n a skinnier rim. it is NOT the remedy unless you are changing the backspacing with the new rim.

what kind of lift do you have on there? you may just need a inch or 2 of that. i probalby would have tried to stay away from the 12.5 inch wide tires though. 12 would probably have fixed your problem.

 

i have 5100s set at 2.5 but i think im going to get the ebiach coils that should give me about me some more lift.on 1st gens billies set at zero and with the springs would give me 3 inches. i got those 15x10s for free so i decided to get some 33x12.50 really wish i would have gotten 32x11.50 would have saved alot of problems