GEN 2 Pulled the trigger on a 2020 Rocky Ridge Raptor

[PlainJane]

the amount of sidewall rubber with 20s and 35s is near identical to stock sidewall on 17s.

hahah

Your math is faulty, even 20s with 37s have less sidewall than stock.

I like the look of 20s and they are needed for a true BBK.

 

[911 Crazy]

Anyone know what happened to the OP?

 

[PorterW1111]

Your math is faulty, even 20s with 37s have less sidewall than stock.

I like the look of 20s and they are needed for a true BBK.

so lets break this out then.

factory tire is a 315/70R17
315 x .70 =220mm sidewall

a 35" tire for 20s 325/60R20
325 x .60 =195mm sidewall

so factory set up has 25mm more rubber than 35s with 20s

divide that in half to apply to the tire radius and you are looking at ~.5 inch of rubber on stock between the axle and the ground

i wont do the math for 37s but they would have more rubber than factory...


just not sure 1/2" of rubber is "really" going to be such a performance loss.

 

[Idaho]

Anyone know what happened to the OP?

Hopefully not scared off by the pages of useless emotional posts within his thread.

I also would like to get word from the OP on what happened.

 

[Moridin]

Anyone know what happened to the OP?

Covid got him and the salesman at Rocky Ridge so this just sort of all worked itself out.

 

[GunMonkeyINTL]

so lets break this out then.

factory tire is a 315/70R17
315 x .70 =220mm sidewall

a 35" tire for 20s 325/60R20
325 x .60 =195mm sidewall

so factory set up has 25mm more rubber than 35s with 20s

divide that in half to apply to the tire radius and you are looking at ~.5 inch of rubber on stock between the axle and the ground

i wont do the math for 37s but they would have more rubber than factory...


just not sure 1/2" of rubber is "really" going to be such a performance loss.

1/2” difference can be a lot when it comes to a critical suspension component. But your math is wrong. You’d double the sidewalk height when figuring wheel height, not half it when figuring sidewall- it’s already given.

So, a factory spec 315r70 tire has 220.5mm sidewall, and 325r60 has a 195mm sidewall; difference of 25.5mm. An inch is 25.4mm, so, in this case, there is a full 1” less between the axle and the ground, as you put it.


A generic 35” with 17” wheel is going to have a 9” sidewall. A generic 37” with 20” is going to have the 1/2” less that you cited.

 

[TXRaptor]

so lets break this out then.

factory tire is a 315/70R17
315 x .70 =220mm sidewall

a 35" tire for 20s 325/60R20
325 x .60 =195mm sidewall

so factory set up has 25mm more rubber than 35s with 20s

divide that in half to apply to the tire radius and you are looking at ~.5 inch of rubber on stock between the axle and the ground

i wont do the math for 37s but they would have more rubber than factory...


just not sure 1/2" of rubber is "really" going to be such a performance loss.

You math is off a little. The sidewall in your example is the sidewall, so you do not divide by two. And yes, you will notice a 25 mm or 1" difference in tire sidewall size. I drove in several different Raptor with various wheel and tire size before purchasing my setup. The 35 x 20s were by far the worst riding trucks of the bunch on and off road. (and the worst looking in my opinion)

On the math problem, you can use the "GENERALIZED" wheel and tire sizes to make the calculations easier. (and somewhat less precise since it does not take into account the different tire MFG actual sizes)

Tire Size - wheel size / divided by 2 = sidewall height

35 - 17 = 18 / 2 = 9 inches
35 - 20 = 15 / 2 = 7.5 inches
37 - 20 = 17 / 2 = 8.5 inches

Using GENERALIZED numbers, the 37 x 20s are slightly smaller than the factory 35 x 17s. In reality, they might be closer than the 1/2" number, but will still be smaller.

 

[K223]

I get what your saying but come on 20's on this truck is no where near 24s on a camaro. the amount of sidewall rubber with 20s and 35s is near identical to stock sidewall on 17s.

and id debate that the majority of the "off road enthusiast" providing their opinion on here are not using their vehicle to the point that 17s vs 20s would make any bit of difference. But also want to mention im not referring to just this thread. the community recently seemed to do over @pj_singh1994 for the 20s he put on his rather tastefull build.

lests start a list of "un-allowed" mods lol
-20s
-a tune
-oil cans
-any lights other than BD, Rigid
- ...etc

hahah

You forgot add on Blowers and larger turbos, aftermarket body panels, super large donut rubber.

Hell man you need to park that sh** lol

 

[Moridin]

The sidewall in your example is the sidewall, so you do not divide by two.

If I understand correctly... he's dividing by 2 because who cares what the sidewall is from the center of the rim up to the 12 O'clock portion of the tire... only the sidewall from the center of the rim down to the 6 O'clock portion of the tire touching the ground is providing any protection from rocks and stuff and actively providing cushioning/bounce.

And I gotta say... I'm finding it pretty hard to believe a measly half inch is so super-serious as to literally be night and day from the stock set-up. C'mon, now... I think people here just hate 20's because... well... they just do and stuff!

 

[TXRaptor]

If I understand correctly... he's dividing by 2 because who cares what the sidewall is from the center of the rim up to the 12 O'clock portion of the tire... only the sidewall from the center of the rim down to the 6 O'clock portion of the tire touching the ground is providing any protection from rocks and stuff.

And I gotta say... I'm finding it pretty hard to believe a measly half inch is so super-serious as to literally be night and day from the stock set-up. C'mon, now... I think people here just hate 20's because... well... they just do and stuff!

The 220 mm and 195 mm numbers he used are the height of the sidewall from the rim to the outer edge of the tire. This means the 6 o-clock and the 12 o-clock portions of the tire are BOTH 220 mm and 195 mm respectively. (ie. the round tire has the same sidewall in all positions) With that said, you do not divide by two to get the difference in height.

In my example, you must divide by two because I am using the full diameter of the tire and wheel. Make sense?

On you point about hating 20s, I do not hate them. I chose 17s because my truck rides BETTER than stock on 37s. If 20s outperformed the factory 17s in any measure, I would have bought them. Period.