Novak Conversions Jeep Wrangler TJ radiator

Still confused on wheel sizing

2005 wrangler X ?

There And Back Again
Original poster
Supporting Member
Joined
Oct 10, 2024
Messages
134
Location
Maine
I know, crayons i tell ya
please bear with me

if i hang a string off the stock fender flair LIKE a plumb-bob
(i think or maybe the fender where they bolt on? PLEASE tell me what one)

A ZERO MM Offset would touch the string ?
A NEGITIVE Offset (say 10mm) would leave a 10mm gap
A POSITVE Offset (say 10mm) would push the string outwards. away from the flair

am i right or all messed up in the head?

0= |

Minus= /

Pos = \

^My computer crayon set lol


thank you
cheers
John
 
  • Like
Reactions: GetBuckGav
I know, crayons i tell ya
please bear with me

https://tiresize.com/wheel-offset-calculator/

backspace_offset_jpg.jpg


Unless you change the wheels you are running, you will likely need to keep those deep flares (not factory) if your state requires that the tire is covered completely. Based on your profile photo, your wheels likely have a negative offset and a low backspacing number (similar to the example on the right in the image above). This effectively pushes the wheel and tire out laterally, requiring deeper fenders/flares if you need them covered.
 
Last edited:
I know, crayons i tell ya
please bear with me

if i hang a string off the stock fender flair LIKE a plumb-bob
(i think or maybe the fender where they bolt on? PLEASE tell me what one)

A ZERO MM Offset would touch the string ?
A NEGITIVE Offset (say 10mm) would leave a 10mm gap
A POSITVE Offset (say 10mm) would push the string outwards. away from the flair

am i right or all messed up in the head?

0= |

Minus= /

Pos = \

^My computer crayon set lol


thank you
cheers
John

For wheel/tire placement in relation to your vehicle, you care about back spacing not offset.

Less backspacing puts the wheel more out, and more backspacing puts the wheels more in. My previous setup was 3.5” of bs, which had the wheel out more than my current wheels that have 3.75” of bs.

What you are describing looks more like camber. Negative camper angles the top of your tire in and positive camber angles the top of your wheel out.
 
  • Like
Reactions: chili_pepper
I know, crayons i tell ya
please bear with me

if i hang a string off the stock fender flair LIKE a plumb-bob
(i think or maybe the fender where they bolt on? PLEASE tell me what one)

A ZERO MM Offset would touch the string ?
A NEGITIVE Offset (say 10mm) would leave a 10mm gap
A POSITVE Offset (say 10mm) would push the string outwards. away from the flair

am i right or all messed up in the head?

0= |

Minus= /

Pos = \

^My computer crayon set lol


thank you
cheers
John

Offset has nothing to do with your flare (corrected from flair) and a string. You don't need to understand offset unless your looking at wheels on the internet and are curious what it's all about. The centerline of the wheel is 0 offset. + and - move out and in from the centerline. NOt really necessary for Jeep wheels. We are interested in backspace. The distance from the backside edge of the rim to the wheel mounting face is the backspace. Offset is stupid because it's in metric. Backspace is smart because it's in imperial. 🤣

https://www.jegs.com/tech-articles/wheel-offset-vs-backspacing-whats-the-difference/
 
Last edited:
It has nothing to do with the fender on the vehicle, but for the sake of your example, positive offset would create the gap, while negative offset would push the string outwards.

Negative offset sticks the wheels out, positive brings them in.
 
  • Like
Reactions: NskLJ
It has nothing to do with the fender on the vehicle, but for the sake of your example, positive offset would create the gap, while negative offset would push the string outwards.

Negative offset sticks the wheels out, positive brings them in.

I think I get it now
at 3.75bs
-19mm offset will stick out "MORE"
than
the -6 offset on the stock flairs

ive got Falkin wildpeak A/T4w 15x9.50 on order and trying to find an aluminum low price black rim for them
 
I think I get it now
at 3.75bs
-19mm offset will stick out "MORE"
than
the -6 offset on the stock flairs

ive got Falkin wildpeak A/T4w 15x9.50 on order and trying to find an aluminum low price black rim for them

If both wheels are the same size, then yes -19 would stick out more. Offset is affected by wheel width, as is backspacing.

I’m not sure what 15x9.50 is. Maybe 30x9.5R15?

3.75 BS will stick out decently far and may look a bit weird with a smaller tire like a 30”.
 
im looking at these wheels and where they will line up on the ORIGINAL fender flairs
as im going back to Stock height

3.75 back spacing
,
https://www.extremeterrain.com/american-racing-jeep-wrangler-baja-satin-black-wheel-ar1725765b.html
,
https://www.extremeterrain.com/mammoth-boulder-black-15-8-J100620.html

but i DO NOT want the tires sticking out from the stock flairs

The only way to know that for sure is to know tire bulge on your rim in addition to the measurements between the wheel mounting face on the rotor, which will tell you the amount of backspacing you need. Most people here are interested in backspacing to create a good balance between scrub radius and rubbing on control arms or upper spring perches, so our purposes are different.
 
Last edited:
Didn't even pick up on that in his post, maybe he is. 👍

Believe he was asking in another thread about wheels, tires, flares and coverage. I assumed this was a continuation of that.

He probably only cared about wheel/tire fitment, but he caught me off guard with that “ zero |, minus \, and positive /“ talk.

I did my best to work it out and realized that I’ve basically said “ €£#$@&+% ” to Blaine countless times when incurring problems.
 
  • Like
Reactions: chili_pepper
and i know im confusing folks here
im asking alot of questions that fold over onto each other
my other(BETTER) half is already steaming with the cost im going to spend dropping this thing down
SHE is HAPPY it will be lower and easier for her to get into (I will miss giving her a helping hand into it :))

and i have too many options rims, tires -them rubber/plastic fender do-hicckies
worrying about driving a costly tire into the metal fender edge and dishing out more money for a mistake

I found a local shop 8miles away that will order the tires for me and mount them so thats a good thing
He says" keep the rims you have (size is posted on my other thread) and the flares they should work with 30inch tires
until i can save up and get a set of rims i like then go back to original flares (springtime)
and i read here that wheels that push out from the hubs short BS can cause problems with my axles failing
BUT
i dont know how much of a JEEP guy he is
hence my questions here

cheers all
john
 
Last edited:
he caught me off guard with that “ zero |, minus \, and positive /“ talk

In pictogram form, I'd say that's wheel camber if viewed from front or rear...if from above, then it's toe....or it could be from the side, in which case it's caster...🤪

You can thank me for clearing that up. :geek:
 
Last edited:
In pictogram form, I'd say that's wheel camber if viewed from front or rear...if from above, then it's toe....or it could be from the side, in which case it's caster...🤪

You can thank me for clearing that up. :geek:

I assumed he meant camber bc he mentioned hanging a string from the fender…but, I’m with you. 🫠
 
Last edited:
  • Like
Reactions: chili_pepper
But it affects how much the wheel sticks out which is what I was saying and what I thought he was trying to determine based on all the questions.

It certainly does, and this is where we simply guide him to not get an overly wide wheel…so he can then skip worrying about offset and focus on his BS. The hope is to help set him up for success without him needing to work so hard.

I understand the offset stuff largely from using it to figure out the BS in my midnight wheel shopping days when BS wasn’t made available. But offset doesn’t really matter if you know what BS to get and what wheel widths work for your setup and tire choice.
 
Last edited:
  • Like
Reactions: chili_pepper
Novak Conversions Jeep Wrangler TJ radiator