Correct Rim Size???

[mustangmarty]

What would be the correct rim size for putting 37X12.50X17 tires on a 77 Bronco?

 

[Mattco]

I would think about a 17 x 10 rim. Not sure of backspacing.

 

[sykanr0ng]

I would go with 17x9 and think 4.5" backspace will be okay.

I have 315/70r17 tires which are about 34.4/12.70x17 on 17x9 wheels and they work and look right.

 

[Broncobowsher]

To some respect it depends on the intended use. More off-road and a narrower rim will run at lower pressures better and keep the rim tucked in a bit more. If this will spend more time on the highway a little wider rim will allow a higher tire pressure and keep a flat footprint on the road. So there really isn't a single answer.

As far as backspacing, try and get the scrub radius correct. It has to do with a line through the ball joints and where that line goes through where the tire meets the ground. I know of it, I know it matters (have had some bad backspacing before and it really sucked), I don't have a good way of figuring it out and how much to have.

 

[mustangmarty]

I'd like to hear from anyone running 37x12.50 on a 76 or 77 lifted 5 1/2 inches. I'll most likely go with 17X9 rims. But what is the most backspacing I can run without them rubbing on full turn.

 

[Lmfp]

17x9 is gonna be the most recommended probably. Most 15" wheel are going to be about 3.5" back spacing and I've noticed the 17s seem to be around 4.5" backspacing. So it'll probably suck the tire in more. I'm going with 17x9s with 4.5" backspacing but I'm swapping in a fw hp 44 to offset it.( still going to gain about 2.5" on each corner though)

 

[Lmfp]

Are your fenders cut? 37s are just gonna rub on the radius arms. Heck my 33s will rub the radius arms on mine if i turn hard enough.

 

[rguest3]

With 17s the only thing that will rub is on the Radius Arms. I would also recommend the 17x9" wheel.

The 4.5" backspacing will rub. I have the 285s on mine and they just rub at full lock and these tires are more narrow than yours. 4" backspacing maybe? The tires will stick out of the front fender flare about 1 1/2" or so.

 

[mustangmarty]

Yes, the fenders are cut. So would 4.25"BS rub the radius arms? What about 4"?

 

[Lmfp]

With 37s theres really no way around rubbing on the radius arms. You'll just need to adjust your turn stops and get used to less turning radius that's why Im going full width axles.

 

[MyOriginal66]

Yes, the fenders are cut. So would 4.25"BS rub the radius arms? What about 4"?

Rubbing the Radius arms isn't really that bad, just noisy

Get some duff arms, it'll help offset the added BS

 

[mustangmarty]

Rubbing the Radius arms isn't really that bad, just noisy

Get some duff arms, it'll help offset the added BS

This is something I've been wanting to do for a long time anyways. Ok, then WITH a set of offset extended Cage (BKG) arms, what would be the least amount of backspacing for 37x12.50x17 toyo open country r/t tires to not rub the arms at full turn? While I'm at it, what about 37x13.50x17 open country m/ t tires as well?

 

[Scoop]

I'm running Walker Evans 17x9 wheels with 4.5" backspacing, 37-12.50 MTRS and have the Duff offset long arms. I had to adjust my turn stops out a bit to keep from rubbing but not a big deal. I've lost a little turning radius, again, not a big deal. You are basically asking what backspacing won't rub - keeping the stock setting on the turnstop adjustment. You have this option - use it! It will open up more backspacing and wheel options.

 

[mustangmarty]

Basically yes. Which backspacing won't rub with these tires/wheels with stock turnstop adjustment. I want the tightest turning circle I can get with these tires.

 

[Lmfp]

You may have to order a custom set with 3.5" backspacing but I still think it's going to rub. Honestly it's just the size of the tires. It won't take but one drive to find out how far you can go with it so it shouldn't be that big of an inconvenience.

 

[Scoop]

Basically yes. Which backspacing won't rub with these tires/wheels with stock turnstop adjustment. I want the tightest turning circle I can get with these tires.

Where are you in Central Texas? You are welcome to drive mine and see if it's an issue for you.

 

[AxlesUp]

i have 37x1250 on 17x9 with 4.5" bs. i am full width with about 6"s of lift. it doesn't rub anywhere or even come close. the tires fit the rims perfectly.

if your stock width your going to have to buy some spacers/order custom wheels or adjust your stops to keep it off the radius arms. i guess you could get aftermarket arms as well which now that i think about it is your best option.

 

[mustangmarty]

Scoop, I may just have to take you up on that. I'm about 90 minutes north of you in Killeen.

What do y'all think of these:

Pro Comp Xtreme Rock Crawler Series 52 Steel Black Wheels 52-7985R2-5, Gloss Black, 17 in. x 9 in., 5 x 5.50 in. Bolt Circle, 2.50 in. Backspace

 

[gr8scott]

Those are nice
http://www.summitracing.com/parts/pcw-52-7985r2-5

 

[mustangmarty]

Thanks. But I mean how much extra stress will these really put on my wheel bearings?

How much will they shorten the life span of my bearings?