offset/back spacing?

[volaredon]

I am looking at wheels for my 78 Fury 2 dr hardtop. All completely stock.
looking at seemingly the same wheels, some say +6mm (~1/4" offset) like teh ones Im looking at. 4-1/4" back space. 15x7.

Then, I look elsewhere and see 15x7, with "-6mm" offset and still 4-1/4" back space.

How can you have both and still a 15x7 wheel? If the back space and width are the same how can offset not be the same? The ones that say "-6mm" say they fit our cars, the ones with "+6" don't say/ but even if they are truly different, somehow, +6 to -6 is almost a 1/2" total.... I don't think either way would be a killer..... both would fit..

but then again if offset were different wouldn't backspace also be different?
and why are all other dimensions in fractional inch and "offset" is given as a metric dimension?

 

[Ray70Chrg]

Have you gotten any additional info on this subject in the past month? If a wheel is 7" wide and has no offset, the backspace would be 3.5 inches. O offset means the back of the mounting flange of the wheel is in the center of the width dimension. -6mm offset moves the back of the flange about 1/4" toward the center of the car. In order to have 4.25 b.s. with -6mm offset, you have to have a 9" wheel. That's how I understand it and hope it helps you. You can find this info on line, just google wheel offset measurements. A 7" wheel w/-6mm offset has 3.25 b.s. You can only change b.s. by changing offset. Offset creates the backspace.

 

[volaredon]

Haven't really looked for more info since then
I did buy a set of new ones from Jeg's that I am pissed about. If you saw the amount of weight they took to balance you would be too/ very out of round.
And one has a blister in the chrome, on back side but we all know how that turns out. I haven't even tried to put them on the car yet.

 

[Ray70Chrg]

Buying stuff online can be real pita sometimes. If you're happy with the other 3 wheels, look into returning the bad one. If Jegs is anything like Summit, they will take back defective items and replace it. You shouldn't have to accept flawed items. Good luck.

 

[33 IMP]

Have you gotten any additional info on this subject in the past month? If a wheel is 7" wide and has no offset, the backspace would be 3.5 inches. O offset means the back of the mounting flange of the wheel is in the center of the width dimension. -6mm offset moves the back of the flange about 1/4" toward the center of the car. In order to have 4.25 b.s. with -6mm offset, you have to have a 9" wheel. That's how I understand it and hope it helps you. You can find this info on line, just google wheel offset measurements. A 7" wheel w/-6mm offset has 3.25 b.s. You can only change b.s. by changing offset. Offset creates the backspace.

Not quite right. A 15x7 wheel is eight inches wide, at least aluminum wheels are. Wheel widths are given from inside bead to bead, each bead being about a half inch thick, you end up with 8" over all. But backspace is measured from the rear edge of the wheel to the mounting face. So a 15x7 with a 4" backspace is zero offset. 15x8 with 4 1/2 bs is also zero offset.

 

[volaredon]

Buying stuff online can be real pita sometimes. If you're happy with the other 3 wheels, look into returning the bad one. If Jegs is anything like Summit, they will take back defective items and replace it. You shouldn't have to accept flawed items. Good luck.

Nope. Not just 1. All 3 that came from Jeg's.
They only had 3, was able to find 1 new one in the box via eBay to complete the set, 1/2 of Jeg's price and the only one not out of round, only one to take a believable amount of weight. 1 of Jeg's wheels has the blister on the chrome but all 3 spin like absolute$#1t on t balancer, all 3 have over 13 oz of lead weight on them. The worst is over 14 oz. They were balanced with clip on weights on inside lip and stick on weights behind spokes they are a US Wheel, chrome 5 spoke, look very much like an old school Cragar. They have the actual cragars at nearly double the price.

Only 1 has the blister on the chrome but that's 1 too many.
The goofy thing? I asked at several Mopar sites as well as asked Jeg's themselves if these were actually American made. They supposedly are. The wheels are stamped as such, so are the boxes, I wasn't putting Chinese wheels on my car. No way.
I contacted Jeg's and told them, also told them I was going out of town for a week, that the wheels would be stacked in the garage, I haven't put them on the car yet. They told me don't worry, have a year, to return defect merchandise, go ahead and mount them up and drive it and see how they do.so we will see. I'm gonna take them to work and a "write up" be damned, (for working on something of my own on shop equipment) I'm gonna check them out myself, on work's balancer

I'm in GA, on way back from picking up a trailer load of rust free sheet metal for my 85 D150. Headed back to Illinois, but stopped for a few days in Chattanooga. My fury is still at my mom's house, I keep it in the garage there over the winter. It will be coming back home, once I get there.

 

[33 IMP]

It takes 14 oz of weight, on a bare rim!?! Wow. If that is with the tire on.......?
I suspect that those might have been returned by someone else, before. Maybe thats why they had three?
Edit: if that 14 oz is with a tire on it, i would suspect the tire, before the wheel. I'd pull the tire off, (after marking its location on the rim) and spin just the wheel.

 

[oldkimmer]

I wouldn’t want to use them on my car. Kim

 

[hunt2elk]

1 of Jeg's wheels has the blister on the chrome but all 3 spin like absolute$#1t on t balancer, all 3 have over 13 oz of lead weight on them. The worst is over 14 oz.

That is a ridiculous amount of weights. They need to go back to Jegs. No way those would live in my world.

 

[volaredon]

Arrgh I tried quoting the last 3 replies to lead this one off, they didn't show up

What I was thinking too. The guy who mounted them claimed to have spun them but I wasn't there to see. I've had problems with both tires and rims at different times taking a ridiculous amount of weight. Last time it was on my Dakota, I'd had the rims on it for 3 dakota's and several sets of tires have been in and off of that set so I knew it was the tires in that case, I made the tire shop order me another set, didn't even take them home. They put a different set on and night and day. In this case the tires and rims are both new to me. So I don't know yet.
I do tire work daily but can't do my own at work as I work for the state govt as a fleet mechanic.
Ethics, using public bought equipment for personal use, etc.... So I had to pay like most people to "have" these put on. Seems like every time I pay to have something done rather than do a job myself I have problems. Every damn time. Also $130 for taxes mount balance and stems is absolutely insane by that's the going rate. And then the places that sneak road hazard into the total makes it even more ridiculous. Most around here don't ask, just assume you want it til you flip out about the bill, then they'll take it off.

 

[33 IMP]

Your tire shop is either utterly incompetent, or lazy. If the balancer told me to put nearly a POUND of weight on, i would first take a serious look at the tire, or, at the very least, dismount the beads and spin it 180°.
If they told me that on three wheels, there is something seriously wrong..... or the guy running the balancer does not know what he is doing!!!

 

[Cranky]

I sold my tire machine when in the middle of my divorce....started selling a lot of stuff thinking I wasn't going to be able to keep my place but so far so good. Still have my bubble balancer and that works pretty good for bare wheels and does good so long as the tires ain't all too wide. Wish I still had the tire machine since the big box tire stores won't touch anything with 5+ year old tires unless it's to take them off and sell you new ones If a bare wheel is taking nearly a pound of weight without the tire....I'd be sending it back! Good tires aren't as bad as cheap tires are and have had as little as 1oz of weight to balance before which was a pleasant surprise. One of the things you have to watch out for with the cheaper brand of tires is out of round. And when is the last time you've seen a tire truing machine?

 

[oldkimmer]

I seen a tire shop trying to balance tires on the inside bead only. Which is fine if the machine is set up for that. Theirs wasn’t. Also I have seen guys try to balance an aluminum wheel with sticky weights by putting them on the inside and outside. Balancing beads work the best. There is a formula so u know what size /weight of bag to put in your tire size. Kim

 

[volaredon]

One wheel only took 2-1/2 oz total. I do wish they'd have stopped when they found the 1st wheel with problems instead of continuing on.
As I've said even if it gets me a write-up I am going to put them on the balancer at work and see w t f is up with them. And I've talked to the shop owner about me bringing them back to him to see for myself why they took so much weight even if it means remounting the new tires and swapping combos of rims and tires. I have other 15" rims and tires around, for my dakota's that I KNOW are good and don't need that much weight, I'd like to take the time to swap the new tires onto my Dakota wheels and the tires from them to the new wheels to compare.

 

[Cranky]

I'm running the 15x8 wheels from a 2000 Durango on my 95 and 96 Dakotas and pretty sure the 2nd gen Dakotas ran then too and so far, they've been pretty good. One truck has Micky's all the way around and the other has Yoko's on the back and Micky's on the front. I bubble balanced all of them and they all have minimal weights and do well at 80. Might be a different story at 100 but can't remember the last time going that fast!

 

[volaredon]

I've run the 16" wheels from my 01 Durango on my 4wd 96 dakota, no issues, I needed new tires for the Dakota and wanted to trial fit the overall size of tires from the Durango on the Dakota before I spent the money, I got the same size tires (265/70) as on the Durango, except in 16s to fit the 96 wheels. I know the 96, 15" wheels are narrower than the 01 16" ones.
The 1st set off 265/70-15 I got for the 96, balanced out like these US wheels that I got for my fury, I had taken them just the rims from the Dakota,and I didn't even leave the place with them once I saw the amount of weight they pounded onto them.iade them order me a different set of tires since I "knew" that set of wheels that I'd brought them.

 

[volaredon]

ok update time. I wound up staying over at work today and (again) re doing a job I paid someone else to do.... NEVER FREAKING FAILS. Every time I pay like a "regular" person to "have" anything done, I end up having to redo their work.

I have better news (yawn, sorry guys) I got them balanced MUCH better, than what I had paid to have done. Definitely more livable, believeable. and none had the horrible "out of round" the owner of the tire shop claimed...... he says he stopped recommending US Wheels, because he has had many with this "problem". and asked me more than once, how much genuine Cragars would have cost.......

I have had several Dakotas. All with 15" wheels/tires. so I took the 3 new wheels/tires that took the ungodly amounts of weight and one of my "saves" from my 92 Dakota (kept as "spares" for my '99) to work and kept the balancer busy for a while. I balanced the Dakota wheel/tire as was and stepped back and watched it spin, had a little side to side but took 2-1/2 oz total to balance.
-- I then spun the new wheel/tire that had the most weight (2 layers of stick on that extended 1/2 way a round behind the spokes plus 6 oz pounded on the inside lip.
It was only 1/4 oz off in that configuration, did not spin as poorly (wobble/out of round) as I was led to believe.
--I scraped off and peeled off 14 oz of weight, hit the "SPIN" and it asked for ~4 oz of weight total. I didn't put on weight it asked for.
--I then deflated that tire and broke the bead, spun the tire on the rim and put it back on the balancer, I had marked the tire pos. related to stem before the breakdown. The weight called for was still significantly less tahn the tire shop had on it but still more than Id liked. the weight position also had shifted. (if it was all "wheel" the weight asked-for position would have been much the same as what the tire shop had done).
--I demounted that tire and the Dakota tire, swapped the new tire off the jeg's wheel and the 1/2 used one from the Dakota wheel, spun them.
The new tire on the Dakota wheel, had about the same amount of side to side in it, as the Dakota wheel did with the old tire. (which wasn't much, maybe 1/8" oscillation. Ive seen worse. And no "hop" up n down. ) And asked for the same amount of weight, within 1/4 oz as that wheel with its original tire.
--I then put the new tire back on its same rim the tire shop mounted it to. and rebalanced it. I broke it down and spun the tire one more time, got it down to 2 oz total weight needed. A far cry from 14.
-- I then spun each of the other 2 wheel/tire combos, all took much less than tire shop had put on but still more than I like to see in anything less than a Semi truck tire. I broke the 2nd tire down, spun tire and reseated it once, came out the worst of the 3 that I took in, at 3 oz total. and no wobble/hop. Spun very true.
the last one took 3 breakdowns/spin/reinflate cycles to get it to its best, which I got down to 1-1/2 oz total weight required. It started with about 12 oz of weight.
But, by doing nothing but scraping off the tire shop's weights and spinning on balancer, none of the wheels I took in and redid, called for more than half of what the tire shop had pounded/stuck onto my wheels. and that was before I broke them down and spun any tire in relation to wheel.

One thing I learned long ago, and it was insisted upon by the owners of the shop I worked at many jobs ago and 25 years ago....
DON'T just pound the weights on as the machine says.... STEP BACK and watch the wheels and tires spin, and regardless of weight called for, put the best, truest spinning ones on the front and if any have any "wobble" put on the back, or if bad enough, replace. most shops DO NOT do this. any that call for a ridiculous amount, go get another from the stockroom and try again. usually (somehow?) that tire that called for ridiculous weight, wants a "normal" amount on the next guy's car. Not always though, but when it does, it's really weird that way.

this place came to me VERY highly recommended, always hear great things, even my son buys all his tires there and takes anything I can't handle (I don't have an alignment machine for instance) and anything he needs "NOW" that I don't have time to give that kind of attention to, he takes there and always seems happy with their work (He invited the owner and his wife to his wedding even) They have done a couple of alignments for me and I haven't had an issue there. And having been an alignment guy myself for 20+ years I think that says something....... before I found them Ive had to pay 2x for an alignment on more than 1 vehicle since I left the alignment shop and lost my access to do my own.......

 

[volaredon]

and I'm down to 1 wheel, to see what Jeg's will do something about/ not 3 like the tire shop tried to lead me to believe. and that is the peeled wheel, also the one with the flat spot on the back bead, like it had been dropped (yet that was the truest spinning wheel, of the 3) If it weren't for the peeled chrome on the back side (of which the blister popped and I got a huge chunk of chrome, when I peeled all the stick on weights off of it)
Now I had called jeg's /and I think I was calm and cool about it, before vacation/ and told them of my issue, and that I would not be able to address it for a couple weeks, from that point...... the guy said he was authorized to drop the price by up to 1/2 or send me shipping return labels for them and either credit my account or put that$$ towards something else..... Being as how they "only" had 3, strangely, and I had to find #4 elsewhere, I'm stuck with wheel #4 if I send these back..... so being as how this is a "summer only" driver that gets parked in a garage over winter, and the peel is so far limited to the back side, I'm inclined to see if he'll give me the whole "1/2 off" and keep them.... as long as they didn't do something stupid like "mis-box" wheels with wrong bolt pattern or something like that.....
I'll be finding that part out this weekend......

hopefully these last 2 posts didnt put someone to snoozeville.......