Off Roading Forums banner
1 - 4 of 4 Posts

·
Registered
Joined
·
1,491 Posts
instead of refering to it as negative/positive offset, i think about the amount of backspacing a wheel has.
take a look at a normal aftermarket 15 x 8" wagon wheel comparing it to a 15 x 10" one, you will see the mounting surface in relation to the inside rim edge is the same,(they hug the brake rotor/drum exactly the same) but the difference is 2" of extra wheel sticking out past your fender flares. they have the same backspacing but different offsets!
so wheels with less backspacing push the wheel out past the fender flares, and wheels with more backspacing move them in under the flares.
don't know about the centerline wheels,

ask CJDave about the beadlocks being illegal in CA, most likely the democratic/feminist/tree hugging/un-informed political decision making process in action!/wwwthreads_images/icons/smile.gif

3/4tonYJ
My Jeep Page
 

·
Registered
Joined
·
1,491 Posts
sorry but there ain't a simple # answer, it depends on wheel width, tire diameter & width, and leaf spring/steering component clearance.
YJ's came factory with more backspacing than most other common wheels, factory or aftermarket. (i'm not sure exactly but i think the 15 x 7" wheels have about 5" of backspacing) Now most aftermarket 15 x 8"(or 10") have 4" of backspacing, this is why you see so many YJ with aftermarket wheels/tires that stick out past the fender flares.
now you can buy(or build) wheels with custom backspacing but you must be careful, if they have to much backspacing the will contact the tierods, or hit the brake drums/rotors before the lug nuts actually seat the wheel. also when turning, the tire will rub on the leaf springs.
and also the less backspacing you have put more stress on the balljoints, wheel bearings etc..(it kind of adds some extra unwanted leverage)
so anyway i would look at some other YJ's noteing the size (tire & wheels) and asking if they rub while truning. my expereince with YJ's is a 15 x 8" rim with a 30" to 33" tire is a good size, and on a 15 x 10" rim 33" to 35" tire is good, (both 8 & 10" wheels having standard 4" of backspacing)
also i've used 15 x 7" (and have them for sale) wheels with 35" tires and i guar0wnTee they will rub when turning.

so my preferance is that the overall tire diameter needs to be decided before choosing the wheel. after the diameter is decided i get the wheel with the most backspacing possible without causing problems (touching anything). now other folks will say "wider is better" but not me.

sorry about the long post, i just got to typing/wwwthreads_images/icons/smile.gif

3/4tonYJ
My Jeep Page
 

·
Registered
Joined
·
1,491 Posts
I never really thought that backspacing has anything to do with alignment. now when your turning(with alot of backspacing) the tires will "scrub" putting alot of extra forces on the steering components. just like bigger tires do.
but i don't see how it can affect toe in/out, camber, or caster(the shopping cart thing) at all? (now more backspacing would exagerate problems due to worn bearings/balljoints/tierods that could show up like a camber or toe problem)

3/4tonYJ
My Jeep Page
 

·
Registered
Joined
·
1,491 Posts
Hmmm, (i seem to be just sitting here thinking) i can't really answer many of those questions but i'll give my 2 cents about steering stuff.(now i'm writing with a trial Jeep in mind also)
Ya, putting more backspacing (than it's designed for) on a front axle will interfere with steering components. unless you put 16.5" wheels on a knuckle designed for a 15" wheel, but thats a bad idea because you want all the leverage you can get by a tie-rod being mounted as far away from axle as possible. (if you use big tires, turn while stopped and have much scrub radius)
Ackerman, is not something that can be adjusted if your going to use a one piece tierod, besides obtaining the "best" ackerman angle is more important at higher speed while cornering to reduce "scrubbing", like NASCAR, it's different for every track (even every corner)
Steering axis inclination is different from design to design slightly but more important is your "Caster & Camber" which is something we have control over,it very much so changes how tight your Jeep turns. Caster/Camber can allow your jeep to turn tighter with a lesser axle shaft U-joint angle/wwwthreads_images/icons/smile.gif,
(I just re-read your post, if your going to drive @80 mph you don't want this degree of caster) Hmmm, maybe YOU are more concerned with ackerman(tire wear)?
this is alot to talk about, i've sat around with my "race car buddies" and talked for hours

Lets keep this post going
later,

3/4tonYJ
My Jeep Page
 
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top