Confused over Wheel Sizing
06-18-2010, 08:37 PM
#1
JK Newbie
Thread Starter
Join Date: Feb 2009
Location: nj
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Confused over Wheel Sizing
Sooner or later we all look to bigger tires and I am about to head down that trail
I have an 09 2dr manual Rubicon, with a 3.5 AEV lift. The application is street with a mild tread adequate for the vehicle image but, biased for low noise and good road manners.
The stock wheel data says 17x7.5 with 6.25" back space and +25mm of offset
In the FAQ section the sage advice says stay between 3.75 - 4.75" for back spacing
It is not clear why the new wheels should have such a different range on the back spacing
I would like to go to an 18" 9" wide with 5.25" back space.
This would be an inch less in back spacing than stock- moving the wheel away from the inside and put the wider wheel 2.5" further out than the stock
If the 9 inch wheel starts with 4.75 backspacing, that pushes the wheel 3" further out than stock.
How do you measure to tell how much interference you might enounter without buying the wheels and tires only to find....
I have an 09 2dr manual Rubicon, with a 3.5 AEV lift. The application is street with a mild tread adequate for the vehicle image but, biased for low noise and good road manners.
The stock wheel data says 17x7.5 with 6.25" back space and +25mm of offset
In the FAQ section the sage advice says stay between 3.75 - 4.75" for back spacing
It is not clear why the new wheels should have such a different range on the back spacing
I would like to go to an 18" 9" wide with 5.25" back space.
This would be an inch less in back spacing than stock- moving the wheel away from the inside and put the wider wheel 2.5" further out than the stock
If the 9 inch wheel starts with 4.75 backspacing, that pushes the wheel 3" further out than stock.
How do you measure to tell how much interference you might enounter without buying the wheels and tires only to find....
Last edited by Paultre02; 06-18-2010 at 08:39 PM.
06-18-2010, 10:37 PM
#2
JK Jedi Master
Join Date: Jan 2008
Location: Austin <--> Colorado Springs
Posts: 11,463
Likes: 0
Received 162 Likes
on
154 Posts
What size tire? And will you have enough left in the budget to throw on some wheel spacers when you figure out how bad you're tires are rubbing?
Food for thought on this one...
Does your new rim really push out 3" further than stock? Or is it 1" further from the BS, with the rim itself being 2.5" wider, with 1.25" of rim being further out on BOTH sides. And the tires on your new rims sticking out even further than that - on BOTH sides?
So is your new tire 3" further out? Or is the inside of the tire even closer to the components and skids and whatever than the stock tire/rim combo?
The recommendations in the FAQ's are there for a reason. Because lots of people have tried the various options, and found the advice to be fairly accurate. (no, it's not 100% accurate 100% of the time for 100% of the people, but it's certainly a good place to start)
To reinforce it - go out to just about any lift mfg's website and look at the suggested wheel backspacing they give. You'll find that their recommendations are generally 'no more than 4.50 BS'. Why is that? Refer back to this one...
"Q: What back spacing will I need on my wheels in order to clear 12.50 wide tires?"
Food for thought on this one...
If the 9 inch wheel starts with 4.75 backspacing, that pushes the wheel 3" further out than stock.
So is your new tire 3" further out? Or is the inside of the tire even closer to the components and skids and whatever than the stock tire/rim combo?
The recommendations in the FAQ's are there for a reason. Because lots of people have tried the various options, and found the advice to be fairly accurate. (no, it's not 100% accurate 100% of the time for 100% of the people, but it's certainly a good place to start)
To reinforce it - go out to just about any lift mfg's website and look at the suggested wheel backspacing they give. You'll find that their recommendations are generally 'no more than 4.50 BS'. Why is that? Refer back to this one...
"Q: What back spacing will I need on my wheels in order to clear 12.50 wide tires?"