Big bend tire sizes -- what AT tires won’t rub??

1210matthewsmith

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Driving on a flat pavement looks to be fine. What about rubbing if you have 245's and some articulation over potholes, frozen and rutted roads, and such...will it rub under those conditions? Otherwise, I may just go to 235/65R17 and no bigger.
I was wondering this same thing looking at this. Wondering how snow ice build up would also be.
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Right. I have done some other off-roading than what I posted in the write-up linked above with even more ruts and holes and never had any issues with the tires rubbing or hitting the fender.

I am eventually going to look into getting a suspension lift (hopefully Ford comes out with a factory lift) but that's mainly for ground clearance so I don't scrape bottom on sharper breakover angles.
 

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Right. I have done some other off-roading than what I posted in the write-up linked above with even more ruts and holes and never had any issues with the tires rubbing or hitting the fender.

I am eventually going to look into getting a suspension lift (hopefully Ford comes out with a factory lift) but that's mainly for ground clearance so I don't scrape bottom on sharper breakover angles.

Thank you for that report and follow-up! ? So it looks like I could go to the 245's from the factory 225's. The roads that you posted look like those in some roads in NY state that I travel on to get to my turkey & grouse hunting or trout or ice fishing destinations except that the earth isn't that southern orange clay color. ? Looking forward to getting an aftermarket skid plate when they become available for my BB when I eventually get it. Thanks once again!
 

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Thank you for that report and follow-up! ? So it looks like I could go to the 245's from the factory 225's. The roads that you posted look like those in some roads in NY state that I travel on to get to my turkey & grouse hunting or trout or ice fishing destinations except that the earth isn't that southern orange clay color. ? Looking forward to getting an aftermarket skid plate when they become available for my BB when I eventually get it. Thanks once again!
Lol and that red/orange clay is no fun to clean off!

And you may already know this but just so that you are aware, I have 245/65R17 tires. Someone else has posted that they had 245/70R17 tires installed and they DO rub slightly. Mine do not. Cheers!
 


Huntyeraws

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Lol and that red/orange clay is no fun to clean off!

And you may already know this but just so that you are aware, I have 245/65R17 tires. Someone else has posted that they had 245/70R17 tires installed and they DO rub slightly. Mine do not. Cheers!

Thanks - I was looking to go from 225/65R17 to either 235 or now 245 tires size tires.
 

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And you may already know this but just so that you are aware, I have 245/65R17 tires. Someone else has posted that they had 245/70R17 tires installed and they DO rub slightly. Mine do not. Cheers!
Have you checked on your speedometer difference since your 245/65R17’s are 29.5” tall and the stock Continental 225/65R17’s are 28.5” tall?
 

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Have you checked on your speedometer difference since your 245/65R17’s are 29.5” tall and the stock Continental 225/65R17’s are 28.5” tall?
@BamaBronco any idea on this? I’ve asked around to no avail. You are the authority on tires now ?
 

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@BamaBronco any idea on this? I’ve asked around to no avail. You are the authority on tires now ?
Use a GPS for speed. Here is the comparison of 225/65R17 vs 245/65R17. Notice the calculated speed difference
Ford Bronco Sport Big bend tire sizes -- what AT tires won’t rub?? Screenshot_20210223-182649

Ford Bronco Sport Big bend tire sizes -- what AT tires won’t rub?? Screenshot_20210223-182707
 

BamaBronco

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@BamaBronco any idea on this? I’ve asked around to no avail. You are the authority on tires now ?
LOL well maybe I'm good for something!

Have you checked on your speedometer difference since your 245/65R17’s are 29.5” tall and the stock Continental 225/65R17’s are 28.5” tall?
I have used a GPS app as well as checked my speedo against a digital speed signal in a school zone that tells you how fast you're going and whether or not to slow down. The GPS app on my phone appeared to be within 1-2 mph of my speedo (in most cases within 1 mph). As for the digital speed signal, it was almost dead on. So if I was showing 50 mph on my speedo, the signal would also reflect 50, sometimes 51. Long story short, this is acceptable to me and within the legal tolerance of speedometer accuracy according to US federal law:

https://www.fmcsa.dot.gov/regulations/title49/section/393.82
 


MattH88

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LOL well maybe I'm good for something!



I have used a GPS app as well as checked my speedo against a digital speed signal in a school zone that tells you how fast you're going and whether or not to slow down. The GPS app on my phone appeared to be within 1-2 mph of my speedo (in most cases within 1 mph). As for the digital speed signal, it was almost dead on. So if I was showing 50 mph on my speedo, the signal would also reflect 50, sometimes 51. Long story short, this is acceptable to me and within the legal tolerance of speedometer accuracy according to US federal law:

https://www.fmcsa.dot.gov/regulations/title49/section/393.82
Makes sense. I'm also worried about odometer readings too over time. If you hear of how of anyone recalibrating, be sure to tag me! haha
 

BamaBronco

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Makes sense. I'm also worried about odometer readings too over time. If you hear of how of anyone recalibrating, be sure to tag me! haha
Sure thing. Hopefully someone will get around to doing it at a Ford dealer, if they offer that service.
 

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I guess those tolerances are acceptable to me as well. I do wonder how many more miles will be added to the ODO after a year, or two? But then I really do not put a lot of miles on a year across my vehicles but my BB is the daily driver. I really do like your 245’s on your ride. Probably will still not upgrade until fall. Oh yeah, nice info above in your screen prints.
 

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I do wonder how many more miles will be added to the ODO after a year, or two?
That's a great question and to be honest, that's not something I had thought about yet. But since you asked, here's my two-cents on the way I understand it:

Comparing the stock 225/65R17 tires to new, larger 245/65R17 tires, there is a tire diameter variance of 3.59%. This means that the odometer will read less than the mileage that has actually been traveled by 3.59% if using the larger tires. So for example, say my BS reflects 90,000 miles on the odometer before I decide to sell it (which is about how long I drove my truck before selling then buying the BS; roughly 3.5 years). Using the same percentage (3.59%), with the larger tires I will have actually traveled 93,231 miles instead of 90,000.

Hopefully my math is right. I may be totally wrong but the way I described it is how I understand it. So for some, being 3,000+ miles off by the time they reach 90k miles may not be acceptable but for me it is. An extra ~3200 miles traveled by that point doesn't really affect the value of the vehicle, IMO. Now, does it affect the long-term wear-and-tear of the vehicle? To some degree, probably yes. However, it may not end up making that much of a difference over time. I will probably still look into a re-calibration at some point, especially if I get a suspension lift.
 
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