16" wheels

[IowaEagle]

You have done great here with your descriptions of what works.  Thumbs Up given.

[carnuck]

I scoff at talks of offset and backspacking. None of that helps you much. It is frustrating that those values are the industry standard. What we need to know is the opposite of backspacing. I've been calling it "frontspacing." What it comes down to is that you need to know how much the total width of your wheels will add up to when bolted to the constant WMS of our axles.

Nobody lists the front spacing because they figure you only need to know backspacing to determine if the wheel will clear the brakes and suspension. I've found that if you know what front spacing you have now, then you can compare it to a new rim and instantly know how much the tire will move in or out from where it is now. With one measurement I can instantly determine how much of a spacer I need or don't need. If you get the tires to be the same width apart you won't have to worry about backspacing at all unless you're also dramatically increasing the width of the rim and tire. Even then I'd rather know front spacing first for comparison.

To find backspacing I put the rim and tire face down on concrete. I then measure from the concrete to the wheel mounting surface. That is the total amount that wheel will add to the axle WMS. Measuring it is the only way to actually know. You can calculate it if you know the backspacing and the total rim width, but that's retarded. First of all most Eagle rims, I know the 5 spoke alloy sport rims with confidence, are 15"x6". That means the space between the beads of the rim is 6". The thickness of the bead itself plus the shape of the tire usually causes the entire wheel to end up about 2" wider than that value. Without the tire the rim is always at least an inch wider than the advertised width. Too many times I've actually seen 15x6 rims called 15x7 because the owner didn't know he was measuring them wrong.

When you go to XJ rims most of them are truly 15"x7" rims. That means there is 7" down in the trough between the beads. The whole rim is actually 8" wide.

If you know the front spacing I can tell you what works and doesn't work. The Eagle Sport alloy rims for instance are about 1-3/4" front spacing. They are hideously recessed into the front fender well and I always add a 1" spacer behind them. On the back axle it is much worse and for those I always add a 2" spacer. Even with the spacers the tire is still well within the fender flare.

My next favorite rim is the Jeep XJ 10 hole alloy rim. That one has about a 2-1/2" front spacing. Basically that means each tire sticks out 3/4" more than a sport rim would, so your total tire width is going to be 1-1/2 wider. For those I do not use a spacer in the front and I use a 1" or a 1.5" spacer in the back. That makes all of my Eagles look much better and gives them all the same total tire widths.

The limit is 4" front spacing. At that point the extreme outside of your front tires will be perfectly flush with the outside of the front fender flares. In the back your fender flares will still stick out past the tires by about an inch. The 15 spoke rims I sold to Phil have that exact front spacing. Those are 15x7" rims that have an extreme width of 8" and the wheel mounting surface is exactly in the middle, which is why the front spacing and the back spacing is exactly 4".

This picture shows Phil's SX4 with the 4" front spacing and no spacers added:



This picture shows my wife driving my Green SW. In that picture those rims have 1" spacers in the front and 1.5" spacers in the back.


This picture shows my Kammback with XJ wire type rims. With those rims you must have spacers or the front wheel will hit the caliper and not rotate. I think pictured you're looking at 2" in the back and 1.5" in the front. I eventually used 1" in the front to get it where I wanted it.







This picture shows 10 hole rims without any spacers and 235/75R15 tires. I had the fender flares on but don't have pictures of it.

If you alter the wheel centerline on the front, you mess with the alignment and can beat the snot out of the front wheel bearings if you go too far either way.

[captspillane]

If you alter the wheel centerline on the front, you mess with the alignment and can beat the snot out of the front wheel bearings if you go too far either way.

Neither is affected. As long as your tires remain inside the fender flare there is no risk of premature wear.  In the most extreme case I quoted you have a 8" wide rim with a 4" front spacing and backspacing. The Wheel Mounting Surface of the wheel bearing is literally the centerline of the tire. It is not a valid argument to conclude that it is unsafe to center your tire over the bearing WMS.

[carnuck]

Not trying to be a , but do you work in an alignment shop? Do you have an automotive engineering degree? The previous owner of my wagon put Grand Caravan rims on and the wheel bearings were replaced twice in 2 years. (he bought the Eagle alloys from me. I wanted the TJ wheels instead because of the rough roads I drive. Much easier to replace.

http://www.hondatuningmagazine.com/tech/htup_0807_honda_wheel_offset_guide_faq_tips_biggest_lip_wheel/wheel_offset_too_much_wrong_suspension_geometry.html

http://forums.nasioc.com/forums/showthread.php?t=870349

[captspillane]

People are full of opinions. I doubt you'll change your mind and you're not about to change mine.

Can we at least agree that the AMC Spirit AMX factory Turbocast rims are within the designed load range for AMC front wheel bearings? I own a set and have measured them. Those have a 4-5/8" front spacing that exceeds the 4" maximum that I recommended. That is equivalent loading as a factory sport alloy wheel with a 2" spacer, which is an inch more than I use. The use of spacers is not excessive as long as you do not let your tire tread exceed the width of the factory fender flares. None of my recommendations exceed a load approved by the factory.

The competence of the installation and quality of the parts are suspect if you had bearings fail in under two years.

My opinion is also supported by the test of time. I've got 250K miles on my Red SX4 with wide offset aftermarket steel rims that are even wider than factory rims with spacers. I jumped the car with those wide offset rims and landed with enough force to push my rear leaf springs straight through my rear floor. The factory original wheel bearings survived and gave me at least four more years of rough service after that event.

[IowaEagle]

Folks often forget how the choice of wheels/tires can affect other components.

[carnuck]

We have people driving full size Chevs on wheels that would make a Honda Civic cringe so I guess it's whatever floats your boat.
SX4 is considerably lighter (and so is my mood today. Finally over the flubug) than the wagon.
I still need to upgrade my front brakes for trailer towing.
As for the installer of the bearings, I guess the AMC dealer can muck things up at times. I do as much of my own as I can these days and haven't had any re-failures except one Made in China set.

[4hammond]

Opions -- on a 15x7 rim with a 3 3/4 back spacing work with a 215 or 225x75x15 work on our Eagles then adding a 1/2 spacer to the rear?

[captspillane]

The short answer is yes. Eagles take 215s and 225s without a problem. The 235's require some trimming but it's still minor. 

I don't know of any decent half inch spacers and would not trust anything that small. You need enough thickness to have a lug nut recessed into the spacer and still have enough thickness left over to have a decent amount of material underneath the lugnut. The spacers I'm talking about bolt to your hub, then they have 5 lugs that your tire bolts to. Done well they are stronger than the rim itself. The minimum thickness of that type of spacer is basically 1".  The maximum is basically 2". The Eagle rear axles are so narrow you can use 2" spacers in the rear with basically any rim out there and then still not have your rims stick out past the rear fender flares.

They do have "spacers" that basically go between the rim and the wheel mounting surface. They are not safe to use. Even if you beat out the factory lugs and put in longer ones those do not center themselves properly and will cause a vibration. If you don't put in longer lugs you will not have enough thread left to safely secure the wheel.

Are you sure it is a 15x7? That would be 7" bead width but the whole rim would be 8" wide. With 3-3/4 backspacing you're looking at 4-1/4" front spacing. That is really wide and you will just barely rub. I'm guessing you actually have a 15x6 and measured the total width instead of the bead width. Please measure the front spacing of the rim if you want to accurately know if it will fit.

[vangremlin]

Well I finally went ahead and got some new wheels and tires.  These are American Racing 895 16 x 7 wheels with Toyo Open Country AT 215/70-16.  I was really tempted to go with a 225/70 but that would have required some trimming.  Maybe I'll go with the 225's next time around! 

These are essentially front wheel drive rims that have a high offset to keep the wheel/tire in the wheel well (more or less).  Nice birthday present for myself!

[Prafeston]

You didn't go with 16s huh?

[vangremlin]

You didn't got with 16s huh?

Doh!  Yes i did, i'll correct my post.  Thanks.

[eagleman]

Me like! Gives it a whole different look and stance. Way cool! And by the way Happy Birthday to ya!

[Amc1320]

Wow those look awesome!

Happy birthday!

[vangremlin]

Thanks for the compliments and thanks for the birthday wishes.  While I can't say I'm enjoy getting another year older, it sure beats the alternative!