Offset backspacing on stock wheels???
- Thread starter kwhines
- Start date
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Tightwadsjeeper
New Member
I think I read somewhere in here that stock rims are 5.5" backspacing, but that you can get away with 5" backspacing as well without any issues.
Anybody care to correct me if I'm wrong?
Luis
Anybody care to correct me if I'm wrong?
Luis
Any confirmation yet on the backspacing on stock 16" alloy wheels?
5" or 5.5" seems like a lot just by looking at them. Bennett says his Cragar 397s are 4" and they seem to be offset more than stock. To me the stock look like maybe 2"?
What's the effect on suspension with wider offset? Maybe a couple inches more doesn't affect things?
5" or 5.5" seems like a lot just by looking at them. Bennett says his Cragar 397s are 4" and they seem to be offset more than stock. To me the stock look like maybe 2"?
What's the effect on suspension with wider offset? Maybe a couple inches more doesn't affect things?
Bonehead
Full Access Member
First, backspaceing and offset are two different measurements,
Offset is measured from the middle of the wheel to the surface that touchs the disc/drum.
Backspace is measured from the inside lip of the wheel to the surface that touchs the disc/drum .
Hope that might clear up a little confusion.
Added offset can effect bearing wear, ball joint wear and basicly every part of the front suspention to an extent, what it does is put the weight and the forces that act on the front suspention farther out than the engineers had intened. But that being said I don't think an inch or two would hurt things. The only time I've seen it cause real problems was with a kid in a front wheel drive car that had 8" wheels with 0!!! backspace(you guy know the look I;m talking about)
The Discount Tire Direct web site list an OFFSET of between 35mm amd 40mm for the (16"x7")wheels they offer for the Liberty. Now being there is aprox 25 1/2 mm to an inch that would be around 1.3" to 1.5" positive offset of the
wheels. Now let see if I'm awake enought to covert this into backspaceing LOL...........Now the wheels are 7" wide and half of that is 3.5" add to that (since are wheels are a positive offset) the above mentioned 1.3" to 1.5" and you get a BACKSPACE of 4.8" to 5" on the wheels. The wider the wheel the more these measurement will change, an offset that will work with one width wheel may not work with another and so on.
So going with a 4" backspace wheel should be a problem any more than that I would say you could have major rubbing problems, but I could be wrong on that.
On a positive offset wheel the higher the offset number the father inside the wheel wheel it will mount, and the lower the number the farther it will stick out (sorry for contradicting(sp?) you Bennett on this one O
)
It looks like that our wheels are a 5x114mm bolt pattern so that is right at a 5x4.5" bolt pattern......can anyone verify the english measurement on the bolt pattern?
One of us with stock wheels need to pull the spare off take a straight edge on the inside lip and measure to the mounting surface ,that will tell us for sure the backspace of the stock wheels,I will do it this weekend if nobody has done it yet since my KJ sits at the post office(60mi away) we park our trucks at 18hr a day and I don't have easy access to it though the week.
Well I hope this helps ................oh and sorry for the long post (biggrin)
Offset is measured from the middle of the wheel to the surface that touchs the disc/drum.
Backspace is measured from the inside lip of the wheel to the surface that touchs the disc/drum .
Hope that might clear up a little confusion.
Added offset can effect bearing wear, ball joint wear and basicly every part of the front suspention to an extent, what it does is put the weight and the forces that act on the front suspention farther out than the engineers had intened. But that being said I don't think an inch or two would hurt things. The only time I've seen it cause real problems was with a kid in a front wheel drive car that had 8" wheels with 0!!! backspace(you guy know the look I;m talking about)
The Discount Tire Direct web site list an OFFSET of between 35mm amd 40mm for the (16"x7")wheels they offer for the Liberty. Now being there is aprox 25 1/2 mm to an inch that would be around 1.3" to 1.5" positive offset of the
wheels. Now let see if I'm awake enought to covert this into backspaceing LOL...........Now the wheels are 7" wide and half of that is 3.5" add to that (since are wheels are a positive offset) the above mentioned 1.3" to 1.5" and you get a BACKSPACE of 4.8" to 5" on the wheels. The wider the wheel the more these measurement will change, an offset that will work with one width wheel may not work with another and so on.
So going with a 4" backspace wheel should be a problem any more than that I would say you could have major rubbing problems, but I could be wrong on that.
On a positive offset wheel the higher the offset number the father inside the wheel wheel it will mount, and the lower the number the farther it will stick out (sorry for contradicting(sp?) you Bennett on this one O
)It looks like that our wheels are a 5x114mm bolt pattern so that is right at a 5x4.5" bolt pattern......can anyone verify the english measurement on the bolt pattern?
One of us with stock wheels need to pull the spare off take a straight edge on the inside lip and measure to the mounting surface ,that will tell us for sure the backspace of the stock wheels,I will do it this weekend if nobody has done it yet since my KJ sits at the post office(60mi away) we park our trucks at 18hr a day and I don't have easy access to it though the week.
Well I hope this helps ................oh and sorry for the long post (biggrin)
Bonehead
Full Access Member
No problem (biggrin)
Tightwadsjeeper
New Member
FWIW... the standard Wranglers (TJ's) have 5.5" backspacing (not offset)... this includes the Rubicon's... I've seen people doing a straight switch of this rim (16" for the Rubicon) to a KJ... that's why I suspect it's got the same backspacing of 5.5".... I seem to recall reading this elsewhere also.
Luis
Luis
tape pulled off the mounting point on the wheel to out side edge of wheel on stock 16X7 steel wheels are 6"
my question is this... looking at the stock wheel tire mounted there is only about an inch of clearance on the sidewall and the upper ball jount. the stock tire is about 9" wide from side wall to side wall (NOT tread width). the tread even on a 29" dia tire is way above the ball joint and wont ever rub. now I am looking at a 16X7 4" BS which should move the edge of the wheel about 2 inches away from the ball joint... and by adding an inch and a halk to the tire width when going to a 31 10.5, that only allows for a half inch of sidewall clearance. now to make it even worse what hapens when the sidewall rollos over it self on a turn or angle, the half inch will def. not be enough clearance! and a 16X8 4.25" bs is accually a 1/4" closer I think (1 inch total... +1/2 inch on the inside - 1/4" for added BS = 1/4 closer)
the problem I see here is this... everyone says what wheels the run and what tire, say "only a slight rub"! well a slight rub on the sway bar from the sidewall lugs on the tread at full lock isn't crap... a slight rub on the side wall on a nice sharp ball joint means flat tire! I say start posting your wheel tire combos with backspaceing and wheel type and where exactly it hits. and we might get somewhere.
my question is this... looking at the stock wheel tire mounted there is only about an inch of clearance on the sidewall and the upper ball jount. the stock tire is about 9" wide from side wall to side wall (NOT tread width). the tread even on a 29" dia tire is way above the ball joint and wont ever rub. now I am looking at a 16X7 4" BS which should move the edge of the wheel about 2 inches away from the ball joint... and by adding an inch and a halk to the tire width when going to a 31 10.5, that only allows for a half inch of sidewall clearance. now to make it even worse what hapens when the sidewall rollos over it self on a turn or angle, the half inch will def. not be enough clearance! and a 16X8 4.25" bs is accually a 1/4" closer I think (1 inch total... +1/2 inch on the inside - 1/4" for added BS = 1/4 closer)
the problem I see here is this... everyone says what wheels the run and what tire, say "only a slight rub"! well a slight rub on the sway bar from the sidewall lugs on the tread at full lock isn't crap... a slight rub on the side wall on a nice sharp ball joint means flat tire! I say start posting your wheel tire combos with backspaceing and wheel type and where exactly it hits. and we might get somewhere.
