Offset advice
10-02-2012, 02:16 AM
#11
Ill do as said.
Many thanks.
Many thanks.
Well that's a 33x12 tire, so on a 8.5" rim I would estimate that the tire would hang over the edge of the wheel approx 1.75" on each side. Since the stock wheels are 7.5" wide with 31x10.5 tires, that means they hang over the edge of the stock wheel approx 1.5" on each side.
With those numbers above, we can conclude that since the wheel you are wanting is 1" wider, it will stick out 1/2" more on the outside (1/2" on each side). Then, since the new tires are 1.5" wider, that adds another .75" on each side. That's 1.25" so far (.75" + .5") Then, add another 1.75" (assuming a -12 offset) to account for the new wheel offset, and that adds a total of 3" to the outside vs stock (.75" + .5" + 1.75" = 3"). So, to verify this, all you need to do is park your pickup on a level surface, (at least level on the horizontal x axis, or the "roll" axis if you know anything about aircraft) hang a plum line down from the ouside of your fender flare, and then measure the distance from your stock tire out to the plum line. If it's approx 3", you're in luck. If not, then based off of that same measurement, adjust the offset of the wheel that you plan to purchase in order to coinside with your desired look.
With those numbers above, we can conclude that since the wheel you are wanting is 1" wider, it will stick out 1/2" more on the outside (1/2" on each side). Then, since the new tires are 1.5" wider, that adds another .75" on each side. That's 1.25" so far (.75" + .5") Then, add another 1.75" (assuming a -12 offset) to account for the new wheel offset, and that adds a total of 3" to the outside vs stock (.75" + .5" + 1.75" = 3"). So, to verify this, all you need to do is park your pickup on a level surface, (at least level on the horizontal x axis, or the "roll" axis if you know anything about aircraft) hang a plum line down from the ouside of your fender flare, and then measure the distance from your stock tire out to the plum line. If it's approx 3", you're in luck. If not, then based off of that same measurement, adjust the offset of the wheel that you plan to purchase in order to coinside with your desired look.
10-02-2012, 05:09 AM
#12
Senior Member
Well that's a 33x12 tire, so on a 8.5" rim I would estimate that the tire would hang over the edge of the wheel approx 1.75" on each side. Since the stock wheels are 7.5" wide with 31x10.5 tires, that means they hang over the edge of the stock wheel approx 1.5" on each side.
With those numbers above, we can conclude that since the wheel you are wanting is 1" wider, it will stick out 1/2" more on the outside (1/2" on each side). Then, since the new tires are 1.5" wider, that adds another .75" on each side. That's 1.25" so far (.75" + .5") Then, add another 1.75" (assuming a -12 offset) to account for the new wheel offset, and that adds a total of 3" to the outside vs stock (.75" + .5" + 1.75" = 3"). So, to verify this, all you need to do is park your pickup on a level surface, (at least level on the horizontal x axis, or the "roll" axis if you know anything about aircraft) hang a plum line down from the ouside of your fender flare, and then measure the distance from your stock tire out to the plum line. If it's approx 3", you're in luck. If not, then based off of that same measurement, adjust the offset of the wheel that you plan to purchase in order to coinside with your desired look.
With those numbers above, we can conclude that since the wheel you are wanting is 1" wider, it will stick out 1/2" more on the outside (1/2" on each side). Then, since the new tires are 1.5" wider, that adds another .75" on each side. That's 1.25" so far (.75" + .5") Then, add another 1.75" (assuming a -12 offset) to account for the new wheel offset, and that adds a total of 3" to the outside vs stock (.75" + .5" + 1.75" = 3"). So, to verify this, all you need to do is park your pickup on a level surface, (at least level on the horizontal x axis, or the "roll" axis if you know anything about aircraft) hang a plum line down from the ouside of your fender flare, and then measure the distance from your stock tire out to the plum line. If it's approx 3", you're in luck. If not, then based off of that same measurement, adjust the offset of the wheel that you plan to purchase in order to coinside with your desired look.
I'am in same boat different flare.lol. I want them flush too I have stock 20" @ 8.5" rim, I just put on 275/65/20 =34.1"
Im wanting to go to 325/60/20= 35.6" Dia or going to 18" but then Im at 12.5 and will stick out way to much. I have Bushwacker Extend-A-fender and there 1.75"
My next Option is Billet Bolt on wheel spacers, and they make them from 1.5" to 3"......
so I'll get my plum bob out and maybe I figure it out....lol....I was never very good at math....lol...even worse now since my car accident..lol....
Thanks for the Insite I'll try and follow that see where it leads me....I wanna go to RBP Chrome 94R rims and BFG KM2 tires....
here is where im at now, a few pics....these are my Rainy winter tires, next ones I want, are for the summer playing and camping.....
10-02-2012, 06:26 AM
#13
What if i decide to go for the RBP 20x10 wheel. What would be the right offset to go for?
Sorry for the endless questions,however i want to make sure im doing the right purchase as expected.
Sorry for the endless questions,however i want to make sure im doing the right purchase as expected.
Well that's a 33x12 tire, so on a 8.5" rim I would estimate that the tire would hang over the edge of the wheel approx 1.75" on each side. Since the stock wheels are 7.5" wide with 31x10.5 tires, that means they hang over the edge of the stock wheel approx 1.5" on each side.
With those numbers above, we can conclude that since the wheel you are wanting is 1" wider, it will stick out 1/2" more on the outside (1/2" on each side). Then, since the new tires are 1.5" wider, that adds another .75" on each side. That's 1.25" so far (.75" + .5") Then, add another 1.75" (assuming a -12 offset) to account for the new wheel offset, and that adds a total of 3" to the outside vs stock (.75" + .5" + 1.75" = 3"). So, to verify this, all you need to do is park your pickup on a level surface, (at least level on the horizontal x axis, or the "roll" axis if you know anything about aircraft) hang a plum line down from the ouside of your fender flare, and then measure the distance from your stock tire out to the plum line. If it's approx 3", you're in luck. If not, then based off of that same measurement, adjust the offset of the wheel that you plan to purchase in order to coinside with your desired look.
With those numbers above, we can conclude that since the wheel you are wanting is 1" wider, it will stick out 1/2" more on the outside (1/2" on each side). Then, since the new tires are 1.5" wider, that adds another .75" on each side. That's 1.25" so far (.75" + .5") Then, add another 1.75" (assuming a -12 offset) to account for the new wheel offset, and that adds a total of 3" to the outside vs stock (.75" + .5" + 1.75" = 3"). So, to verify this, all you need to do is park your pickup on a level surface, (at least level on the horizontal x axis, or the "roll" axis if you know anything about aircraft) hang a plum line down from the ouside of your fender flare, and then measure the distance from your stock tire out to the plum line. If it's approx 3", you're in luck. If not, then based off of that same measurement, adjust the offset of the wheel that you plan to purchase in order to coinside with your desired look.
10-02-2012, 10:14 AM
#14
Senior Member
What width of tire and offset would you be looking at? Can't do any math without those two variables included. What you really need to do is hang a plum line down from the outside of your flare and then measure from the tire out so we know exactly how many inches those fender flares stick out. Once we know that, we can just work the math backwards.
10-02-2012, 10:33 AM
#15
I will revert back with the required variables,once i do theexercise.
What width of tire and offset would you be looking at? Can't do any math without those two variables included. What you really need to do is hang a plum line down from the outside of your flare and then measure from the tire out so we know exactly how many inches those fender flares stick out. Once we know that, we can just work the math backwards.
10-02-2012, 11:30 AM
#16
Then, you need to take into account 1/2 of the added width from your wheel/tire. (Since 1/2 the width increase will be on the inside and 1/2 on the outside).
Figure out how much you need to bring your wheel out to match your flare. Then subtract 1/2 the width. The difference is the offset you need to make up. Since offset is in MM, just dump your number into Google and convert to MM. Whatever the result is the change you'll need to make in offset (reducing the number and possibly getting a negative offset).
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Grandpa's Grocery Getter (10-02-2012)
10-02-2012, 05:31 PM
#17
Senior Member
You can do the math yourself. You don't have to post here for us to do it for you. All of the factory wheels (as far as I'm aware) have an offset of +44 MM (give or take a few mm). Lower (or negative) offset will make the wheel stick out more.
Then, you need to take into account 1/2 of the added width from your wheel/tire. (Since 1/2 the width increase will be on the inside and 1/2 on the outside).
Figure out how much you need to bring your wheel out to match your flare. Then subtract 1/2 the width. The difference is the offset you need to make up. Since offset is in MM, just dump your number into Google and convert to MM. Whatever the result is the change you'll need to make in offset (reducing the number and possibly getting a negative offset).
Then, you need to take into account 1/2 of the added width from your wheel/tire. (Since 1/2 the width increase will be on the inside and 1/2 on the outside).
Figure out how much you need to bring your wheel out to match your flare. Then subtract 1/2 the width. The difference is the offset you need to make up. Since offset is in MM, just dump your number into Google and convert to MM. Whatever the result is the change you'll need to make in offset (reducing the number and possibly getting a negative offset).
Hahahahahaha I'll still mess this up.....LOL.....but thanks Again!!
10-02-2012, 10:19 PM
#18
Senior Member
I would think somewhere around a zero offset with a 295-305 tire should get you pretty close.
Also, keep in mind 25.4mm = 1"
The stock FX4 18s are 18x7.5" and are a 44mm offset.
If you look on most tire manufacturer and seller websites, they list the width on a given measured wheel.
Check this out: http://www.nittotire.com/Tire/trailgrappler#size
295/60R20 Nitto Trail Grappler is 12.13" wide on an 8.5" wheel
Using a zero offset makes the math easy. Basically 6.07"(half your width) would stick out from the mounting point on your hub/rotor assembly (where the back of the wheel touches your hub/brake rotor).
Comparing to the stock setup:
275/65R18 should be about 11" wide. 44mm offset = 1.73" that the wheel is moved inboard. 11"/2 = 5.5'' - 1.73" = 3.18" sticking out from the hub.
So your tire should move outward about 2.9". Does that put you close to the edge of your fender flare?
The wheel width only slightly effects the tire width.
i.e. a 295 tire might be maybe .25" wider on a 9" rim then 8.5". I'm unsure of the spec there but I wouldn't expect a huge change there. Unless your going from like 7" wheel to a 10" wheel.
Also, keep in mind 25.4mm = 1"
The stock FX4 18s are 18x7.5" and are a 44mm offset.
If you look on most tire manufacturer and seller websites, they list the width on a given measured wheel.
Check this out: http://www.nittotire.com/Tire/trailgrappler#size
295/60R20 Nitto Trail Grappler is 12.13" wide on an 8.5" wheel
Using a zero offset makes the math easy. Basically 6.07"(half your width) would stick out from the mounting point on your hub/rotor assembly (where the back of the wheel touches your hub/brake rotor).
Comparing to the stock setup:
275/65R18 should be about 11" wide. 44mm offset = 1.73" that the wheel is moved inboard. 11"/2 = 5.5'' - 1.73" = 3.18" sticking out from the hub.
So your tire should move outward about 2.9". Does that put you close to the edge of your fender flare?
The wheel width only slightly effects the tire width.
i.e. a 295 tire might be maybe .25" wider on a 9" rim then 8.5". I'm unsure of the spec there but I wouldn't expect a huge change there. Unless your going from like 7" wheel to a 10" wheel.
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Grandpa's Grocery Getter (10-03-2012)
10-03-2012, 12:45 PM
#19
Senior Member
To figure out how much a wheel and tire setup will extend farther than stock I prefer to use this tool.
It's the same thing as the calculations above, but done for you. Give it a try.
It's the same thing as the calculations above, but done for you. Give it a try.
10-24-2012, 07:54 PM
#20
Blue Oval
check it out
0 offset 18x9 Rockstars with 325/65s... I could use your bushwackers to cover up the pups. I'm out about 2.5 - 3 inches... 305's will fill those flares up.
0 offset 18x9 Rockstars with 325/65s... I could use your bushwackers to cover up the pups. I'm out about 2.5 - 3 inches... 305's will fill those flares up.
