I just spent my stimulus money on two sets of new tires from Coker to replace the 24-year old tires on my '68 and '69 4-4-2 convertibles. The tires are BFG Silvertown red stripe radials, size P215/70R14, mounted on original 14X6 SSI wheels for both cars. The tires look great but I had a heck of a time getting them balanced. I had to take them in twice to get a ride that I'll have to pretty much accept. Four of the ten tires really looked out-of-round when put on the spin balancer and I used them as rear tires. The tires on the front looked better and balanced out better but the ride still isn't as perfect as it was with the old tires. Has anyone had similar experience with new tires like this? I have the sense that I'll just stick with these tires as my outings are usually just around town to shows, or lately, slow-moving make-shift parades (with the corona virus going on now). I'm just curious as to what others have experienced and if this is common or if they sent me a batch of lousy tires!

Randy C.

 

Yes, same thing I experienced. Now that was several years ago. Tires were junk as far as I'm concerned. I never even considered buying any more tires from them. I just buy good tires and run blackwalls.

 

Call them and complain. How much weight did you have to add for balancing?

 

Did you break them back down and rotate them 90* on the wheel? As was asked above, how much weight did it take to balance them?

 

You have to use a lug centric adapter when balancing SS1 wheels. They are a stamped wheel and will not true up using a cone adapter on the spin balancer.. If you can't find a shop with a lug centric adapter,bubble balancing is better than using the cone adapter. I had these exact tires on my 66 442 but were 225/70/14 and rode great.

 

I bought some cooper cobras recently and the shop called me up and said they required to much weight to balance, he tried the rims separate and they were spot on, he tried the 90degree thing too w no joy.

summit took them back and sent me new ones.

 

I had the same issues with the same tires two years ago and it took a while to get a decent performance on my 66 Cutlass convertible. I had them mounted on my SS1 wheels and balanced and no matter what with another balance they were still horrible for balance and noise. I decided to move from my SS1s to 14X7 steal wheels, I had them rebalanced by another shop that did a better job on balancing. I have experimented with different tire pressures and settled on 35 pounds. And finished it off with a very good alignment at a shop that had experiance with classic cars. I finally have a much better ride now. Beyond that I have a friend who is a pretty sharp mechanic at a new car dealer ship and I had him look at my tires and the conversation focused on the tread design. His thoughts focues around the tire tread and considered those tires to have a coarse tread. Hence vibration and noise.

In the end when you apply that tire to an old convertible things happen like noise, shimmy etal. My car rides very nicely now but it was a long experiment. I love the red lines on my car and have no idea what I will do about red line tires.


Wayne

 

With regards to weight, on the worst one it was 2.75oz on the inside and 5.00oz on the outside. Since I didn't want any weights to show on the outside, they used peel-n-stick weights on the back center of the wheel. That's one of the four that went on the back. They didn't break any of the wheel/tire combinations down and move the tire on the wheel but that certainly would have made some difference. And the cone adapter was used in every instance in lieu of a wheel centric adapter.

I lost my bubble balancer mechanic friend about three years ago. He did all of the previous balancing and it worked out fine. I looked around here for someone with a bubble balancer and came up empty-handed. I thought maybe my mechanic friend here would have one but all he had was the spin balancer.

I'll just live with what I have for now. I don't do a lot of freeway driving - most is just around town. But I was surely disappointed at the seemingly poorer tire quality. I've never seen a tire wiggle around so much on a spin balancer as I did with some of these tires.

Thank you all for your insights. That will help me in the future if I revisit this balancing issue.

Randy C.

 

Coker Tire is no longer in the hands of the Coker family and qc has been abysmal since that happened. Not sure where their radials are made now. At one time, Mexico, but I've had 2 sets of Chinese-made radials on the 78 wagon and other than getting only 35k miles out of them, they were great. So I don't see why Coker can't make a good quality tire esp considering what they cost.

This is not a new problem either. Ppl have been bitching about it for several years on the AACA forums.

 

I tend to be a “Princess And the Pea” type when it comes to brake pulsation, shimmy, tire balance, etc. I would bring up a method that has helped get numerous sets of tires/wheels balanced to or close enough to “right on” when conventional technique did not meet my standards. ROAD FORCE BALANCE uses a spin balancer that looks like it loads the tire as if the car’s weight is on it. One nice thing is that it seems easier to pinpoint and confirm bad tires. (the weight needed as mentioned above would have put me in therapy even if it was on my F350!)

Thankfully my tire guy acquired such a machine a year or two back so I didn’t have to navigate having him not balance them and bringing freshly mounted new tires to a nearby Firestone shop to be road force balanced. Most dealerships have these machines as well but are likely to charge exorbitant fees for balancing.

 

Before you do that find a shop with a bubble balancer or lug centric balancer. If you're in Albany, OR that's only an hour or so from Portland, right? I would definitely be pissed off if hi quality tires I bought from Coker didn't balance properly. It's cheaper and easier to get a set of blackwalls at WalMart that will balance properly.