Update: my brother was at the tire shop to install new wheels and tires. Now the first problem, I gotta say, is not rubbing, but robbing! I know work force is expensive in US, but 108 usd for mounting the tires on wheels, balancing and putting on the car?!?! Seriously?! Here it woud cost 20-25$ max. Now the good: the fronts with 15x7 4" bs and 255/60s went without a problem at least so far. And the BAD! the back tire (285/70 on a 15x10 5.5" bs) is rubbing seriously against fender's inner lip even on the side where the chrome trim is temporary off. The result: brother ended up paying another 60$ to mount old tires on stock ralleys and back on the car. now i have new wheels and tires in front and olds in the back. What's next? no idea any suggestions? Oh and not to forget: thanks Larry for such a full reply and answers to all my questions i wonder how much heavier or lighter is my 350 4bbl with ac.
I understand your desire to get a tall tire in the rear. Not my cup of tea but..... My suggestion is to get a more normal height tire like 275/60 (at the max) or get more backspace on the wheels if you want to keep those tall itres. Or get airbags and raise the rear up
Getting new tires and/or wheels is not an option, there's no time for that, my brother has to send the car, he's leaving on 10th himself and besides I like this combo that's why i bought it after all))) So i guess I'll have to deal with it already here in Georgia, which is easy, problem is I'll have a set of 15x7 stock ralleys here, that I won't need and wanted to sell in U.S. and I'll have to custom clear the new combo that could be mounted on the car and therefore free of any tax and charges. So it's a double loss for me) But it is what it is
If you are willing then you could trims the lip and Chrome. You can also buy coil spacers to raise the rear a bit. I like the look of 275/70R15 on 15x10 with the same backspacing
what are the pros and cons of airbags vs coil spacers? which one is better? Sean I thought you had 285/70r15 at least that's what I found in all of your older posts and those posts and pics impressed and inspired me to go with that size to be honest and I cant find 275/70r15 tires neither online nor in your posts but than again I wonder why did 285/70s work so well on your car and are rubbing on mine?
Yeah you are right they were 285 it’s been a few years I forgot. They fit fine on mine, but all cars are a bit different. I would trim the inner lip, and add the coil spacers
Yeah that's what I'll do too, but maybe with airbags, since airlift 1000 came with the car. It's strange though people put 295/50s on 15x10 5.5 bs and even wider tires without trimming and rubbing, so width is not that big of a problem as the height in this case I guess?
Every car is different. The body may not be exactly square on the frame. It isn’t uncommon to have more room on one side than the other. A 10” rim is pretty much the widest you can go, and some cars may need 5 5/8” BS.
Hi all! long time no see) I returned with major updates! 1. The car arrived!!! 2. Installed the wheels (15x7 4"bs with 255/60 front and 15x10 5.5" bs with 285/70 rear) 3. Used coil spacers to accommodate 285/70s in the back 4. Had two rubbing points both in rear both on drivers side: inner wall of tire against exhaust pipe and outer wall against inner lip of the fender moved the pipe a little and cut the lip both are clear now. Now the current issues: on bumps and holes, especially when loaded, rear tires rub against the inner arches (wells) the airlift 1000 that came with the car was outdated probably. the bags were cracked in multiple places. Installed the rubber coil boosters. they were dirt cheap, 2.5 bucks for a set of 6 so three on each side but the guy had only one set but he's getting more on Thursday. It helped a little and thinking on adding some more at least as a temporary solution. So what should i do long term is anyone using boosters should i leave them or go with air lift or something else?
I'm happy with the height i just want to stiffen the rear so it doesn't bounce like a boat on a wave and hit the arches. P.s. what do you mean by "riding like a tank"?
If you stiffen the rear the travel in your springs and shocks will reduced, hence riding like a tank or lumber wagon or " bounce like a boat on a wave."
I think you have several issues here. First, here are the specs for your 285/70 tire compared to the most often used 275/60 tires on our cars: 285/70 recommended rim width - 7.5 - 9.5 in. Diameter - 30.75 in. Section width - 11.5 in. Tread width - 8.6 in. 275/60 Recommended rim Width - 7.5 - 9.5 Diameter - 28 Section width - 11 Tread Width - 8.9 So, here are the issues as I see them: 1) You have the tires mounted on 10 inch rims which exceed the spec and causes the section width (bulge) to be even more than 11.5 inches. And, your offset is a bit off. 2) To get that "overstuffed" look you like, you have given up almost a half inch of tread width. (traction?) 3) To get those 285/70 tires to stop rubbing all the time you will probably have to play with spacers, bags, etc. to the point that your car will ride very rough and probably have more tire wear. 4) A point that has not been mentioned is that you are killing your rear axle ratio with an almost 31 in. tall tire vs. a 28 inch. I don't know what your engine, tranny & rear axle combo is but, here is an example. Say you are running a 3.42 axle with the factory 26.5 inch G60 tires the way Buick built them. Going to a 275/60 tire reduces your effective axle ratio to 3.25. Going to your 285/70 tire reduces your axle ratio further to 2.96. If you are running lower numerical rear gears like 3.08 the difference is even more significant, like 2.66 effective ratio from the G60 to your 285/70. Just a few things to chew on if ride quality and performance are of interest to you. You could probably resolve all of the above situations by biting the bullet and investing another $300-$400 in a pair of the 275/60 tires. They fill up the wheel wells pretty well. Enjoy your Buick whatever avenue you choose to take.
In first place I wanna thank you for your time and attention. Before buying this combo i also looked up the specs but to make sure decided to ask here too: Here's my question: "Oh and one more more question: is it okay to run 285/70s on 10inch wheels? coker recommends 9.5 inch wide wheels max for those tires." SkylarkGeorgia, Feb 8, 2018 And here's the answer I've got: sean Buick 76 Buick Nut Staff Member "Yeah they look really good I think I can try to dig up pics... I have some 295/50R15 on 12 inch rims too... it spreads out the thread for more footprint. There are tons of racers doing this... the race class for 275 tires are normally on 10 or even 11 inch rims" sean Buick 76, Feb 8, 2018 So I decided it was okay...maybe I was wrong? Regarding spacers and bags i think even if i had no rubbing issues I'd still stiffen the rear it's to bouncy and loosy to my taste. As for gear ratios you might be right I have to do some homework though. its 350 4bb/350th don't know the axle exactly. Unfortunately new tires will cost me way more than 300-400 I'd have to buy them in US ship them and pay the taxes)
Understand. Economics always plays a part in most car hobby decisions. Just for your information, if your Skylark (not a GS, I presume) is a '70-'72, your axle ratio (if it hasn't been changed out previously) is likely either a 2.73 (standard) or a 3.08. (optional). Either way, your performance is affected with a super tall tire.
