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Wheel/tire assistance

nsiti

Newbie
Joined
Aug 3, 2017
Messages
30
Hi all,

I'd appreciate your assistance in helping me confirm my wheel/tire combo, which I've done a fair amount of research on thus far.

This is for my 1977 Bronco, with 2 inch lift kit and cut fenders (with flairs). I uploaded a picture in my Garage.

I am leaning towards BFG A/T 32 x 11.50R15 tires on 15 x 8 rims. For rims I am considering the Ion Alloy 171 polished wheel (or similar, ie Mickey Thompson Classic III). The wheel is 5x5.5 (139.7 mm), 3.44" backspace (-27 offset).

I need to ship the wheels to the Bronco which is overseas so I need to make sure I'm not missing anything. The tires will be bought locally.

Thanks for your advice.
 

bronconut73

Bronco Guru
Joined
Aug 7, 2012
Messages
9,916
Generally speaking ....2 inches of lift with cut fenders will allow 33x12.50x15 on a 15x8.
Your 32x11.50 would appear to have some extra room.

For some comparison purposes,....WH (vendor above) has a shop vehicle called Gramps. It is sitting at stock height with 33x12.50x15's on 15x8 wheels. I am sure it is a tight fit but that should give you some more confidence in your decision.

I will let DirtDonk (Paul) chime in here. He works at WH and may be able to post a pic of old Gramps.
 
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nsiti

Newbie
Joined
Aug 3, 2017
Messages
30
Generally speaking ....2 inches of lift with cut fenders will allow 33x12.50x15 on a 15x8.
Your 32x11.50 would appear to have some extra room.

For some comparison purposes,....WH (vendor above) has a shop vehicle called Gramps. It is sitting at stock height with 33x12.50x15's on 15x8 wheels. I am sure it is a tight fit but that should give you some more confidence in your decision.

I will let DirtDonk (Paul) chime in here. He works at WH and may be able to post a pic of old Gramps.

Thank you for your thoughts. I am currently running 32x11.50x15 tires which require replacement. I was debating whether to move up to 33's but was hesitant as I am not sure how they would look. I have seen pictures of 33's on 10 inch wide wheels and they look rather square to me, which appears much larger than what I have now. Not sure how 33's would look on an 8 inch wheel. I also read that they require more power and I only have a stock engine.
 

rguest3

Contributor
Bronco Guru
Joined
Dec 13, 2012
Messages
3,778
Nsiti - have you changed the gears in your axles or are they the stock 3.50s?

I would not go much bigger than 31s without a gear change.
 

68ford

Bronco Guru
Joined
Dec 26, 2004
Messages
2,710
I really dislike the look of 10in wheels. Like you said the look square. I know tire manufacturers say 10in wide wheel for a 12.50, but I have never seen a OEM tire ever look like a 12.50 on a 10 in wheel. Most desert racers that still run 33 and 35 in tires, run 7 in wide tires. Looks much better and you end up with more positive seat for the bead. Less likely to blow a bead. I would recommend 7in wheels if your running 32x11.50s.
I run 35x12.50 on 8in wheels.
 
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nsiti

Newbie
Joined
Aug 3, 2017
Messages
30
Nsiti - have you changed the gears in your axles or are they the stock 3.50s?

I would not go much bigger than 31s without a gear change.

Hi, I have not changed the gearing, they are stock. Another reason to be conservative, I guess. I have 32 inch tires now (probably on 7 inch wide rims) and am thinking of staying with a new version of the BFG A/T tire.

Further researching the Ion Alloy 171 wheels, they don't seem to come with lug nuts, or open caps for the fronts. Is that a concern, ie can I use the existing ones from my current setup, or better to buy new hardware? On the other hand the Mickey Thompson Classic III wheels look identical and seem to come with hardware and offer open caps at an extra cost. Any feedback on helping choose between these two wheels would be appreciated.

Thank you.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,345
Yes, the 33's would likely fit. But since you're running 32's now and are happy with them in both fit and performance, I would not hesitate to stick with that size.
Glad they still even make that old size!

Your "stock" gearing could actually be 4.11 already, since that was a factory option. Most did come with the 3.50's mentioned, but being a '77 you likely also have an automatic transmission, which makes the transition with slightly larger tires less of an issue around town. Which might be why the 32's feel alright now.

The 8" wide wheels will be fine with either size, but are as wide as you'd want to go on an 11.50 wide tire. If you thought a 12.50 looks square, you should see an 11.50 on a ten!

The 8" wheels are a better choice in many cases even for the wider 12.50" tires on a Bronco. And are well within the safe range, but some places (large chains mostly) won't mount that combination unless it's on that particular tire manufacturers recommended list. With BFG having changed their sizes a few years ago, they likely list an 8.5 to 10 inch range. Or maybe even a 9" to 10" range.
With that backspacing/offset setup though, the wheels will still fit like wider wheels in the fender. Kind of giving the false impression of a wider wheel, but without the shape of the tire changing. You're still going to notice a difference if you have 7" wide wheels now. But it's still a good combination. I run mine on 7" wheels and prefer that. But 8's look good too.

The '77 needs the clearance at the steering knuckle/arm, but the 3.44" backspacing specified in your list should work fine. I believe most wheels up to about 3.625" backspacing will fit the steering arms on a '76 or a '77.

At 108mm the center bore should be (I think?) about 4.25" or so? For those with good conversion-fu, is that correct? If so that should be more than big enough. 'Ya gotta watch out for those pesky center bores these days!

I can't see the info, but it looks like the lug holes use a standard taper. Problem is you can't trust pics sometimes because they might show a generic version. But if that's correct then your old lug nuts should work as long as they were for a similar style.

Center caps can be very wheel specific, but lots of brands fit different brands of wheels too. So i don't have an answer for you there. You could measure your existing ones and see if they'd be close.
I prefer no caps myself, but with modern wheels the caps often do look pretty good.
Up to you if you want new ones or not. Just because they are not listed as coming with them, does not mean you can't purchase them from the wheel company separately.

I did not look too closely, but your choice does not seem out of line. Sorry you have to go through all the hoops of shipping overseas, and wondering if you made the right choice. Or worse yet, getting them there only to find out they don't fit!
And speaking of that, I would definitely NOT go with the larger tires in your case. Your rear flares are of the early style with the more vertical leading edge. This means a little less tire clearance and a chance you could rub the flare and it's nice paint.

Great looking Bronco by the way!

Paul
 

rguest3

Contributor
Bronco Guru
Joined
Dec 13, 2012
Messages
3,778
nsiti - Are you stuck on the 15" tire and wheel size? I personally prefer the 17s which have MANY additional tires sizes and wheel choices.

For Example - Here is a 77 (2 1/2" Lift) with a 17x8.5" wheel and 285/70/17s. 4.75" backspacing and clears knuckles with no issues. However, I would suggest a 4.11 gear with this combo.
 

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nsiti

Newbie
Joined
Aug 3, 2017
Messages
30
Yes, the 33's would likely fit. But since you're running 32's now and are happy with them in both fit and performance, I would not hesitate to stick with that size.
Glad they still even make that old size!

Your "stock" gearing could actually be 4.11 already, since that was a factory option. Most did come with the 3.50's mentioned, but being a '77 you likely also have an automatic transmission, which makes the transition with slightly larger tires less of an issue around town. Which might be why the 32's feel alright now.

The 8" wide wheels will be fine with either size, but are as wide as you'd want to go on an 11.50 wide tire. If you thought a 12.50 looks square, you should see an 11.50 on a ten!

The 8" wheels are a better choice in many cases even for the wider 12.50" tires on a Bronco. And are well within the safe range, but some places (large chains mostly) won't mount that combination unless it's on that particular tire manufacturers recommended list. With BFG having changed their sizes a few years ago, they likely list an 8.5 to 10 inch range. Or maybe even a 9" to 10" range.
With that backspacing/offset setup though, the wheels will still fit like wider wheels in the fender. Kind of giving the false impression of a wider wheel, but without the shape of the tire changing. You're still going to notice a difference if you have 7" wide wheels now. But it's still a good combination. I run mine on 7" wheels and prefer that. But 8's look good too.

The '77 needs the clearance at the steering knuckle/arm, but the 3.44" backspacing specified in your list should work fine. I believe most wheels up to about 3.625" backspacing will fit the steering arms on a '76 or a '77.

At 108mm the center bore should be (I think?) about 4.25" or so? For those with good conversion-fu, is that correct? If so that should be more than big enough. 'Ya gotta watch out for those pesky center bores these days!

I can't see the info, but it looks like the lug holes use a standard taper. Problem is you can't trust pics sometimes because they might show a generic version. But if that's correct then your old lug nuts should work as long as they were for a similar style.

Center caps can be very wheel specific, but lots of brands fit different brands of wheels too. So i don't have an answer for you there. You could measure your existing ones and see if they'd be close.
I prefer no caps myself, but with modern wheels the caps often do look pretty good.
Up to you if you want new ones or not. Just because they are not listed as coming with them, does not mean you can't purchase them from the wheel company separately.

I did not look too closely, but your choice does not seem out of line. Sorry you have to go through all the hoops of shipping overseas, and wondering if you made the right choice. Or worse yet, getting them there only to find out they don't fit!
And speaking of that, I would definitely NOT go with the larger tires in your case. Your rear flares are of the early style with the more vertical leading edge. This means a little less tire clearance and a chance you could rub the flare and it's nice paint.

Great looking Bronco by the way!

Paul

Hi Paul, and thank you very much for your time and advice!

Yes, I have automatic transmission, and otherwise stock running gear. I'll have to investigate what the ratio is.

It sounds like the 10 inch wheel width on a 32 inch tire is fairly safe, but will be a bit blocker than my current set-up on a 7 inch wide wheel, which I think I can live with.

Also, you are correct that 108mm center bore is equivalent to 4.25 inches. Glad to hear that will work!

I will investigate the taper with regard to the lug nuts. Then decide if they need to be replaced due to age.

Thanks for your comment on my Bronco, love the truck and wouldn't trade it for any other! :)
 
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nsiti

Newbie
Joined
Aug 3, 2017
Messages
30
nsiti - Are you stuck on the 15" tire and wheel size? I personally prefer the 17s which have MANY additional tires sizes and wheel choices.

For Example - Here is a 77 (2 1/2" Lift) with a 17x8.5" wheel and 285/70/17s. 4.75" backspacing and clears knuckles with no issues. However, I would suggest a 4.11 gear with this combo.

Hi Rguest3, and thanks for your suggestion.

The Bronco you pictured looks like a very nice one, but a bit too tall and "muscular" for my ageing tastes. Also, a bit of a risk to go in the direction of a larger diameter tire, given that I have to ship the wheels overseas which necessitates a more conservative decision for me.

Does anyone have any comment regarding the differences between Ion Alloy and Mickey Thompson wheels? Pro's / Con's to either? Thanks in advance.
 

Unknown

Contributor
Sr. Member
Joined
Jan 21, 2012
Messages
695
Just for reference, this is a 33" x 10.50 on a 15 X 8" wheel. I'm 2.5 suspention lift with 1" body lift.
 

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