Sponsored

Gladiator rubicon 4" readylift with 37" 20x12 question

Zachanadandy

Well-Known Member
First Name
Zach
Joined
Oct 17, 2023
Threads
4
Messages
3,023
Reaction score
4,785
Location
Patterson, ca
Vehicle(s)
2023 gladiator Mojave
Occupation
Electrical foreman
You'll be totally fine with 20" wheels and 37" tires. That's 17" total sidewall

A stock Gladiator with 17" wheels and 33" tires only has 16" of sidewall.
Aside from the load range E tire, I think the ride will always be better with more sidewall. In my opinion the mojave rides better on 37s than it did on 33s with the stock 17" wheels. I wouldn't run 20" wheels personally, but I'm sure it will be ok. I wouldn't call it good, and definitely not better than stock.
Sponsored

 

JT1

Well-Known Member
Joined
Nov 13, 2020
Threads
7
Messages
745
Reaction score
721
Location
Oklahoma
Vehicle(s)
2021 Gladiator Willys
No, you have to go back to your wheels and their backspacing/offset.

You opted to go with a -44, which is the same as the OEM wheels. Now you're adding a wheel and tire that are wider than OEM. So the inside of your wheel and tire are actually getting closer to the hard parts up front. Fine when going straight, going to rub hard parts when turning.

You want to go with a -12 to 0 on the wheel.

You/your wife may want the aesthetics of the 20" wheel, but truth be told she'll be much happier in the JT with a 17" wheel & tire combo. Your tire is your first shock absorber, the taller the sidewall the more capability it has to absorb road shock.
Factory wheels are +44. He'll be fine to the inside, but a wheel that wide is going to have issues depending on lift and bumper decisions.
 

Wheelin98TJ

Well-Known Member
First Name
Ryan
Joined
Jul 27, 2021
Threads
12
Messages
3,717
Reaction score
4,380
Location
Devils Lake, MI
Vehicle(s)
2021 Jeep Gladiator
Occupation
Bean Counter
Aside from the load range E tire, I think the ride will always be better with more sidewall. In my opinion the mojave rides better on 37s than it did on 33s with the stock 17" wheels. I wouldn't run 20" wheels personally, but I'm sure it will be ok. I wouldn't call it good, and definitely not better than stock.
I don't understand the bolded part.

If there's more sidewall than stock, wouldn't it ride better like your Mojave does with more sidewall?

Edit: Are all the 37x12.50x20 tires load range E? If that's a yes, I think I understand what you're saying.
 

Zachanadandy

Well-Known Member
First Name
Zach
Joined
Oct 17, 2023
Threads
4
Messages
3,023
Reaction score
4,785
Location
Patterson, ca
Vehicle(s)
2023 gladiator Mojave
Occupation
Electrical foreman
I don't understand the bolded part.

If there's more sidewall than stock, wouldn't it ride better like your Mojave does with more sidewall?

Edit: Are all the 37x12.50x20 tires load range E? If that's a yes, I think I understand what you're saying.
The particular tire listed is load range E, combine that with basically the same sidewall as stock and I'd bet it would ride much stiffer. A load c 37" on a 20" rim might ride slightly better than stock thanks to the extra 1/2" of sidewall (we ride on the radius not the diameter) but that's negligible in my opinion. Add a full 2" of sidewall by going to a 37" tire on a 17" wheel and now you have a much more compliant tire over bumps.
 

kevman65

Well-Known Member
Joined
Mar 8, 2020
Threads
51
Messages
3,879
Reaction score
5,757
Location
H
Vehicle(s)
J
Factory wheels are +44. He'll be fine to the inside, but a wheel that wide is going to have issues depending on lift and bumper decisions.
You're right, dyslexia kicked in.
 
  • Like
Reactions: JT1

Sponsored

Wheelin98TJ

Well-Known Member
First Name
Ryan
Joined
Jul 27, 2021
Threads
12
Messages
3,717
Reaction score
4,380
Location
Devils Lake, MI
Vehicle(s)
2021 Jeep Gladiator
Occupation
Bean Counter
The particular tire listed is load range E, combine that with basically the same sidewall as stock and I'd bet it would ride much stiffer. A load c 37" on a 20" rim might ride slightly better than stock thanks to the extra 1/2" of sidewall (we ride on the radius not the diameter) but that's negligible in my opinion. Add a full 2" of sidewall by going to a 37" tire on a 17" wheel and now you have a much more compliant tire over bumps.
The way people talk about 20" wheels on here sometimes, it's as if they are implying the tires will be "low profile" tires. They aren't.

You don't need 17" wheels to make 37" tires ride nice and comfortable. 35" tires with 20" wheels is plenty of sidewall. 37", even better.

Of all the vehicles on the road running 20" wheels, maybe 0.5% have 37" or larger tires.
 

Zachanadandy

Well-Known Member
First Name
Zach
Joined
Oct 17, 2023
Threads
4
Messages
3,023
Reaction score
4,785
Location
Patterson, ca
Vehicle(s)
2023 gladiator Mojave
Occupation
Electrical foreman
The way people talk about 20" wheels on here sometimes, it's as if they are implying the tires will be "low profile" tires. They aren't.

You don't need 17" wheels to make 37" tires ride nice and comfortable. 35" tires with 20" wheels is plenty of sidewall. 37", even better.

Of all the vehicles on the road running 20" wheels, maybe 0.5% have 37" or larger tires.
There's a ton of vehicles running around on street tires, low profile tires, etc and I don't want any of it on my Jeep. The rule of thumb back in the day was double the wheel size at a minimum when choosing tires for an off road rig and I'll stick with that as it's always served me well. Sure back when everything came with 15" wheels it was easier. In my opinion I'd say 40's minimum for a 20" rim but you can run whatever you'd like.
 

Wheelin98TJ

Well-Known Member
First Name
Ryan
Joined
Jul 27, 2021
Threads
12
Messages
3,717
Reaction score
4,380
Location
Devils Lake, MI
Vehicle(s)
2021 Jeep Gladiator
Occupation
Bean Counter
There's a ton of vehicles running around on street tires, low profile tires, etc and I don't want any of it on my Jeep. The rule of thumb back in the day was double the wheel size at a minimum when choosing tires for an off road rig and I'll stick with that as it's always served me well. Sure back when everything came with 15" wheels it was easier. In my opinion I'd say 40's minimum for a 20" rim but you can run whatever you'd like.
I've never heard that double the wheel size rule. It seems strange because like you said, we all had 15s back in the day. And since we all ran 30" or taller tires, it would've been a very easy rule to live by.

If it is a rule of thumb for off road, it doesn't apply here because OP is doing this on his wife's street Jeep.
 

Zachanadandy

Well-Known Member
First Name
Zach
Joined
Oct 17, 2023
Threads
4
Messages
3,023
Reaction score
4,785
Location
Patterson, ca
Vehicle(s)
2023 gladiator Mojave
Occupation
Electrical foreman
I've never heard that double the wheel size rule. It seems strange because like you said, we all had 15s back in the day. And since we all ran 30" or taller tires, it would've been a very easy rule to live by.

If it is a rule of thumb for off road, it doesn't apply here because OP is doing this on his wife's street Jeep.
There's no such thing as a street jeep, maybe 1 that doesn't go off road yet....
 
Last edited:

Sponsored

Camaroboi13

Well-Known Member
First Name
Justin
Joined
Aug 22, 2022
Threads
13
Messages
1,810
Reaction score
2,903
Location
SoCal
Vehicle(s)
87 XJ Pioneer, 17 WK2 3.6, 18 JLU 3.6, 22 JTOD 3.0
Occupation
LEO - Life in Chino
Everything in this thread having to do with the height of your tires, ignore it.

What you need to take care of is the width AND the offset of your wheels. If you can find a good looking 20x9 wheel, jump on it. 20x12 might work, but 20x12 with a -44 offset will not.
 
OP
OP
Kyleax1

Kyleax1

Active Member
First Name
Landon
Joined
May 18, 2024
Threads
4
Messages
32
Reaction score
16
Location
Alabama
Vehicle(s)
2020 gladiator rubican
Occupation
Hvac
I had my order changed to 20x10 wheels. It changes the offset to -18, but still has the same backspacing at 4.79. Hopefully that will work fine and im swapping to stubby bumper.
 

Vtur

Well-Known Member
First Name
Le
Joined
Mar 6, 2021
Threads
11
Messages
1,948
Reaction score
2,305
Location
Norcal
Vehicle(s)
JTOD
Occupation
Electrical Foreman
Unless you have some good shocks and bump stops, 20s on a gladiator ride alot harsher than on an suv or trucks with IFS. The harsh is not from compression but from when the wheels decompress after hitting bumps, especially when just one wheel hitting them due to the SFA and heavier wheels and tires. The non impacted side will put more pressure on the impacting side to decompress even quicker.
 

Wheelin98TJ

Well-Known Member
First Name
Ryan
Joined
Jul 27, 2021
Threads
12
Messages
3,717
Reaction score
4,380
Location
Devils Lake, MI
Vehicle(s)
2021 Jeep Gladiator
Occupation
Bean Counter
Unless you have some good shocks and bump stops, 20s on a gladiator ride alot harsher than on an suv or trucks with IFS. The harsh is not from compression but from when the wheels decompress after hitting bumps, especially when just one wheel hitting them due to the SFA and heavier wheels and tires. The non impacted side will put more pressure on the impacting side to decompress even quicker.
When the wheels decompress?

Have you ever ridden in a Gladiator with 20s?

I have a Gladiator with 20s and 35” tires. When people ride in it, they often comment how nice it rides.
 
 







Top