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Topic Review (Newest First)
05-24-2010 09:09 PM
ericnova72 215/70 is not narrow and short, it is the same 8.5" wide(sidewall) but taller than a 215/60. 70 or 75 series tires will be even taller due to the aspect ratio. A 60, 70, or 75 series tire in 215 width is still 215mm wide, only the height is different.

When going to 15" in place of 14" you are already gaining an inch in diameter just from the wheel, so the aspect ratio has to be smaller to maintain the same overall diameter as the 14" tire was so it will fit in the wheel opening designed around the 14" tire. This is why short tires like 195/65R15(25.98" tall, not really short enough though), 205/60R15(24.68"), and 215/55R15(24.31") have been suggested.

The 215/60R14 is nominally 24.15" tall, real close to the 215/55R15(24.31") is.
05-24-2010 07:30 PM
fast68 he wont remove the valence he spent loads of cash to repair and paint it and he is one picky mofu

what about 215 70

why cant that narrow and short of a sidewall tire not work on this?

right now its got 14" 215 60 on it and its close to the frame rail in rear of the wheel opening when the wheel is turned full lock

im afraid to go any wider or even same 60 series

especially since its 15x8 rim

so im thinking 215 70 or 215 75

right?

hmmmmm

i hope because hes taking it to the shop tomorrow to do this
05-24-2010 05:56 PM
a1supersport That valance is the problem. The G-body cars I've had, either had:
78-82 15X8 Vette alloys 225/60-15 (front), or
15X7 reversed Cragar SS 195/65-15 (front)

The tires cleared lock-to-lock. The tire (w/the cragars) would rub only if I hit a good bounce (at the upper/inner fender, not while turning). The vette rims cleared.

P.S. Leave the valance off. It looks better without it. And it solves your tire dilemna.
05-24-2010 03:33 PM
ericnova72 Using 215/60R15 as an example,..... the "215" is tire width in millimeters(25.4mm = 1") measured at the widest bulge of the sidewall(known as "section width") when mounted on its recommended rim width(7" in this case). 215mm is 8.46". The "60" part of the number is sidewall height in percentage(known as "aspect ratio"), a 60 series tire is 60% as tall as it is wide, in this case 5.08"(60% of the 8.46") from bead seat to top of tread. Overall tire height is the 15" rim plus TWO sidewall heights(one top, one bottom)5.08" x 2 =10.16", for a total height of 25.16".

This is how the math is, but tires true sizes vary a good bit from brand to brand. Don't ask me why, it is a pet peeve of mine, the tire companies have a standard for measurement but tires seem to vary (up to an 1" in both height and/or width) for the same size between two different companies.

The 215/60R15 in this example will be slightly wider at the sidewall when on a 8" rim, maybe 8.75" instead of 8.46". If you look tires up in a catalog they all give a recommended(or measuring rim) width for each size tire.

In your case it is not the width that is the total problem, it is the height, which is why I suggested a low profile percentage like 50 or 55 to get it to clear. A 215/50R15 will still be 8.46" wide across the sidewalls on a 7" rim but will only be 23.46" tall because of the 50 series profile.
05-24-2010 11:18 AM
fast68 wow crazy hmm.. that sucks..


yeah ive seen alot of the 15x7 s10 elky steel rallies, see them on the s-10 trucks alot. had a 93 pickup the other day with these 15x7 rallies on it,.

its crazy how 1" wider causes this much of an issue

damn.

which way is a narrower tread width with the tires? a larger second number right? aspect ratio number?

wouldnt a higher number be narrower and have less chance of touching the lower fender wheel opening tip down there?


thanks
05-22-2010 08:19 PM
ericnova72 The difference between the 7" stock wheel and the 8" wheel you are trying to use is that they both have the same(or nearly) backspace, so with the 8" wheel the total difference is on all the outside half of the wheel, 1" wider. Since the rotor, caliper and wheel pivot around the line drawn through both upper and lower ball joints, that means the outside lip of the wheel swings in a larger arc when steered from lock to lock. The 8" wheel would fit just fine with a 4.25" to about 5" backspace, which would put the added width mostly, or all, on the inside half of the wheel.

The '83 Monte SS my mom had was 15 x 7" factory Sport wheel that looked almost identical to the 14" wheel you currently have on the Elky, just the colors are reversed, wheel is silver with black accents around the shaped holes. They were 3.5" backspace IIRC which is perfect with a 7" wheel. It had 215-60/15 Goodyear Eagle GT's on it from the factory, and Eagles tend to run shorter on sidewall height compared to other brands the same size we put on later in the cars life.

You might get the 8" wheels with too little backspace to fit but it will take a low profile tire to do it - 215-60 or 205-55, 215-55.

You size problem with 8" wheels without enough offset is common to most GM cars, my '72 Nova will not take an 8.5" wheel unless the backspace is 5", which leaves 3.5" on the outside half of the wheel. ....Recognize that familiar 3.5"-ish dimension again?
05-22-2010 07:40 PM
eloc431962 No luck on my end, But it looks like you found what the problem might be with the wheel size instesd of the tires Hummmm never thought about the wheel size you are trying to use.


Cole
05-22-2010 07:08 PM
fast68 well damn that sucks

cant believe 8 wide cant work ok

thats crazy

never have this problem on any other vehicle. so thats why i assumed it would be fine on this one

it figures that it had to be this particular vehicle that this problem occurs on...

hmmmm

well shoot

but i still dont see how it would make a diffference only 1" narrower wheels(only 1/2" narrower both sides of the wheel)if you dont change tire width height that only sucks in the width at the tire beads

and not the tread width, where it may rub the spoiler fascia whatever thing

so what the heck?

im just not seeing how rim width is gonna make tire tread move or clear the lip any better or differnetly.....

i dont like elkies any more now..... what a pita car......truck... thing... whatever it is..

i alreayd hated it when we went to start trying to find new parts for it and omg its a nightmare no one makes new parts that you need for these, wow..... you have no idea how much of a nightmare it is to find so many parts for these things wow..... it took about three years to finally find the last piece, except for a new oem style radio antenna in which we still have not found one of....


grrrrrr....

im glad i dont own it or id have shot the damn thing with a 410 or a 12 guage by now(i dont own a gun though) or put it into a tree or off a gravel pit ledge or something....


i looked up today on the carpart.com junkyard parts search site for stock wheels for these and they dont evne give an option for any 15" wheels at all.

only 14x7 plain steel, and the 14x7 s-10 style steel rallies these have,. like ours has, and both my s-10 trucks out here have...
why is that?
and on the door sticker of this elky its 14x7JJ


thanks again!
05-22-2010 05:43 PM
ericnova72 Problem you are fighting is not the tire size but the fact that you are trying to fit 8" wide wheels with only 3-3/8" backspace. You need a 7" wide wheel at that backspace, or 4-1/4 to 4-1/2" backspace with the 8" wheel. The increased width with small backspace makes the wheel sit out farther from the spindle centerline between the ball joints, making the outside edge of the tire swing a bigger arc when turned. This is why it is fouling the SS skirting.

A 60 series tire may get the job done, but I can't say for sure from a distance.

The 8" rim with 3-3/8" backspace also won't fit real well on the rear without jacking the car up to keep the fender lip off the tire sidewall.

All G-body's from 78-82 have 14" wheels, after 1982 it was 15" on performance models like Monte SS and Buick Grand National and Hurst Olds/442. Most standard low performance models after 1982 still had 14" wheels. It's just the way GM did it, don't know why.
05-22-2010 11:19 AM
fast68 awesome cole thanks so much! i just went by where i know of another one identical to ours is that has 15 on it but its not home at the moment

so hmmmmm

im waiting for a couple blue ones i know of also 15" on them to get home near here so i can maybe look at them

but of course none of them have the ss spoiler front piece on them like ours has

hmm


i cant believe its been this big of an issue to simply put 15" tires on this thing wow..

any other vehicle no issue at all

crazy,,,,

thanks!
05-22-2010 10:58 AM
eloc431962 I will be driving past one here in a bit.
I'll stop if it's home and look see what it has on it and post back later if you haven't already found out.


Cole
05-22-2010 10:54 AM
fast68 i have to find out for sure what will fit on this elky

because weve had this thing at the shop in bloomington twice now trying like hell to get tires to fit on the frontof this thing

and damn.......


60 mile trips each time and you know....


so if you know a size that will clear the ss spoiler on this thing for sure then lemme know!

im gonna try and locate one of these 80s elkies around town with 15" on it and see whats on it

none are ss though
so hmmmmmmm



thanks!!
05-22-2010 10:48 AM
eloc431962 Try a 65 series tire, I had to drop down to a 205/65/15 on the front of my camaro to keep the stance i wanted. Every thing else would rub, I think 205/65/15 should fit.JMO


Cole
05-22-2010 10:23 AM
fast68
15" front tire fitment issue 85 elky

have a stock 85 elky

have 15x8" wheels 3 and 3/8"" backspacing

having a hard time figuring out what size tires to run on the front that will clear the front SS spoiler valence.


went from 237 75 15

to

225 70 15

to 215 65 15

the last ones will fit but there is a chance the tire may hit the spoiler when the wheels are turned to full lock

what size tires will clear these stock 80s SS elkies?

what are you running on yours?

why were there no 15" options on the 78-up el caminos? all wheels were 14" these years this model

why?

i see ppl running 15" wheels on these all the time here especially the old steel camaro rallies

no problem

what size front tires though??

before we stripped the car down and totally restored it. tarp is because my brothers s-10 pickup bed was next to it and fell over on it and busted out the glass haha, yeah it was fun putting a new one in, oh boy....:




day after putting in the rebuilt original 305 bored 030 over engine i personally built from scratch with my brother. and before beginnint to strip it to nothing for restoration. new seat, new dash, new door panels, new carpet, all new rubber everything on entire car, reset the quarter glasses, you name it..




we drove it around town in a lawn chair because the seat was at the shop getting rstored at the time:







thanks

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