Coker Bias Firestones vs. Coker Radials... has anyone done a back to back comparison?

Hi guys!

I just got the Model A on the road... and, well, you know... it's been about 6-7 years since I've done any kind of mileage in a car with bias plys...

So my first drive resulted in my teeth about being rattled out of my head.

It's my fault, as I hadn't balanced them.

My neighbor got some balancing beads for me at his work... and they work great!

Here's a tip... your wife's vibrating tooth brush (or anything else she has that fibrates)... just use a clear tube with a funnel... attached to the valve stem on your inner tubes... and bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz... those little beads JUMP right in!

I'd attach a pic but... uh, well... uh... I didn't take one.

Anyway... the beads worked real good. But I still have a vibration that comes in at 60-65mph or so.

When I jack the back of the car up, and run it... the tires aren't too round.

The suckers are out maybe 1/4" or so... which is way too much to have shaved.

So I was thinking about switching over to their radials. 16"ers... I don't like the look as much, but if they work, they work.

Anyone had any success with them?

Has anyone actually done a back to back comparison?

Thanks guys!

Sam

 

Yeah I have ran both sets from Coker. Right now I have the Excelsiors on the car and run all over the place - no problem. They fixed a bouncing issue I had with the bias plys on the front. For some reason the radials are more forgiving of poor suspension issues (my thinking). I had another car that ran bias plys for 1000s of miles and never an issue - none - but this car likes the radials better than the bias.

 

There is no doubt radials are going to be smoother. HRP

 

My first thought is to return them but I guess it's to late. Why would a company sell new tires that are 1/4 out of round ?

 

Think about it,,the car sit for 6 or 7 years,,they flat spotted. HRP

 

Also just a note here - if you are using Dynabeads or other balancing beads as you state, if they sit for a while they can clump together and you may experience a violent shaking due to the imbalance. After a few miles they will loosen right up again and work fine.

Have you checked your wheels for lateral and horizontal run out? While it sounds like a tire issue it may be a good idea to check out if the wheels are true....

 

Just throwing some ideas out there...

Have you tried a dismount and remount to make sure the tire is seated concentrically to the rim? Also, what kind of runout do you have (if any) on your wheels? 1/8" is not uncommon on Kelseys. If the tire has another 1/8", sometimes you can mount them so they cancel each other out...

Neal

 

There is a difference in running smooth and bouncing like a basket ball! ha ha ha -

 

The wifey would have my head if I borrowed her "fibrater" No"soup" for me! One year...


Hopefully the vibration after sitting for years isn't the tread separating from the carcass. I'd have a close look...

 

If I read correctly, he didn't say those tires sat for 6-7 years, he said it was that long since he drove "a" car with bias.

 

I will never run bias again. the last set is my last. never designed to run that fast I bet.. mine did the same thing, vibrations started above 60.

 

Sam - I started out with Firestone bias plies on my roadster. They rode horrible and the fronts also started a 'bounce' over 70 mph. Never tried the balancing beads.

After 1,000 miles I switched to the Excelsior radials. Much better.
Here's a little review/comparison I wrote up:
http://www.jalopyjournal.com/forum/showthread.php?t=729926&showall=1

You'll see I did have problems with one of the radials, but Coker replaced it, no charge.


Malcolm

 

I drive the HELL out of mine with these.... No problems EVER. They are round and balanced. This is probably my 10th set of Coker Firestones, all have been perfect. Never understood the continuing bitch about these tires.

 

A good friend of mine is running 4.50/7.50-16 Firestone bias plies on his Model A Coupe and they ride and drive great.. even at higher speeds. It's crazy -- I think he just got lucky and ended up with a good set. He didn't even balance them!

It has the traditional transverse leaf front and rear suspensions. (P&J ladder bars out back, spring-over-axle up front)

 

I also run bias 600x16 in front and dirt trackers in back.No problems all the way to California and back from the mid west.

 

I had bias stones and no problem except wanting to follow lines or cracks in the road. Just switched to Excelsior radials recently,BUT between me doin stuff on the car and the really lousy weather we've had here,I haven't driven on them yet*&&%&---Pretty soon!!!!

 

Tires not round thread #51. 3/18/2013

 

Spend 1100 on a set of Bias and Tubes - Then Spend 1600 on Excelsior Radials and Tubes - Adds up!

Why improve the bias when they lead to such great sales on the replacement radials!

 

I must just be lucky, I guess. I hear all these stories about bias doing one thing or another, but mine couldn't ride or handle better. Just the other night as I was driving along in my 27 I was commenting to myself how well the car tracks and steers. None of that road wander or vibrations you hear others attribute to bias plies. I can one hand it on all but the worst road surfaces.

The car has been that way for over 25 years and with probably 3 sets of tires over that time. Very confusing.

Don

 

Never a problem with bias plies.. And they're traditional too....

 

Man... you're not going to believe this!

I jacked up the car, put it on jack stands... ran it in gear while a buddy watched the ture turn.

He instantly noticed that the drum was wallowin' around.

Not like a little... like A LOT!!

<iframe width="420" height="315" src="http://www.youtube.com/embed/0n8i064zDdI" frameborder="0" allowfullscreen></iframe>

So, at low speeds, the Coker Tire ran true.

But at about 45mph and above (maybe to 60mph) on the jack stands... the tire began to shake violently!

Crazy! But the drum apparently had "core shift" in a BAD WAY!

Threw the tire off it was so bad!

How bad?

The drum is approximately 1/4" thicker from one side to the next!

It is machined true to the drum pilot and lug nuts...

But the casting is waaaaaaaaaaaaaaaaaay off!!

I don't think I mentioned it before... but I was experiencing a vibration when I stopped.

But when I spun each wheel with the brake lightly dragging... they worked fine.

Like Chopper Bob said "I think we killed two birds with one stone!"

Apologies to Coker for thinking their tires were that bad off. But I never imagined that a bad drum could cause a tire to go out of round!

But that's a lot of weight!

Sam

 

I had a drum like this i just took off.

 

I think it was mentioned that the radials can hide imperfections in the drive train, you may be lucky you didn't spend the money on the radials, they may have rode better enough, that you never noticed the drum issue...

I had drum issues on my Nash, when the heavy handed kid at the tire store tried to beat out the studs, they thought they should switch out those "wrong way threads" when I was putting new tires & wheels on, as they didn't have chrome left hand thread lug nuts... didn't ask me 1st either... those old drums are much thinner on the face than the newer drums... had to have my machinist buddy chuck it up in a lathe & re-true it, as good Wagner Nash drums are rare as hens teeth

as far as ride, been a long time ago, but my previously owned 65 Galaxy 500 with bias tires rode near as good as my Caddy with radial tires...

 

how crazy??? are those new drums?

 

I got mine from speedway.

 

Correct.

And I would assume it was made in China.

I bought a rear end out of a '40 tudor and it went into Matt's Roadster... these two "new" drums were on it.

BTW, the new USA drum is AWESOME... no vibration, the pulsing when I brake almost went away, my colesterol went down and I got lucky last night.

So, BUY USA!!!

Sam

 

Cool Model A Sam.......you miss the '55 yet? Too bad it was never for sale back when I had money.

 

Not yet!

I have a '57 that I want to build or trade for a '55... and am doing "The Drag Rod" now... which will make the '55 seem like a Honda Accord...

Sam

 

I can't tell you how many drums I have tried, and all of them are out-of-balance. Very difficult these days to find new ones that run true. If anybody has a source, please please post it up.

I called Kanter about this problem, and they too are experiencing the same frustration and will no longer guarantee the trueness of the drums they sell.

It's a problem.