Author Topic: Flat spots on Bias-ply tires  (Read 6364 times)

Pex68

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Flat spots on Bias-ply tires
« on: January 08, 2008, 02:46:19 AM »
Anybody know a good way to get flat spots out of bias ply tires?  These are Coker redlines about 2 years old and about 5 miles on them.  Sat for maybe 4 months at 32 PSI and all have flat spots now.  Remember hearing something about over inflating them?  If so to what PSI and how long?  If not any other suggestions???
Thanks, Chris.
Chris P
1968 Sequoia Green SS 396/325 M20

sd1968z28

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Re: Flat spots on Bias-ply tires
« Reply #1 on: January 08, 2008, 02:32:47 PM »
do a couple of burnout switch frt to rear and repeat all will be fine.

JohnZ

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Re: Flat spots on Bias-ply tires
« Reply #2 on: January 08, 2008, 05:19:14 PM »
Usually, about 10-20 miles of driving will smooth them out. The joys of bias-ply tires.....  >:(
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Pex68

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Re: Flat spots on Bias-ply tires
« Reply #3 on: January 08, 2008, 10:49:35 PM »
do a couple of burnout switch frt to rear and repeat all will be fine.
Yeah, thatís what we used to call "Accu-Balancing" when we were kids.

I'll try driving on them but my fillings may come out before the flat spots!

Thanks guys!

rich69rs

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Re: Flat spots on Bias-ply tires
« Reply #4 on: January 09, 2008, 04:58:30 AM »
I threw away my bias ply repros this past summer and installed a new set of B. F. Goodrich Radial T/A's.  Only way I know to really do it.

I had purchased them new in 2000 and they never did work well.  65 mph shook the car regardless of how many times balance and wheel bearing adjustments were checked.  New set of Radial T/A's and viola!  No issues.
Richard Thomas
1969 RS

sd1968z28

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Re: Flat spots on Bias-ply tires
« Reply #5 on: January 09, 2008, 02:25:01 PM »
do the burnout, it will work plus be tons of fun!

jeff68

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Re: Flat spots on Bias-ply tires
« Reply #6 on: January 10, 2008, 06:45:09 PM »
Not that it helps get rid of the flat spots, but most tire manufacturers recommend over inflating the tires (10-15% IIRC) if the vehicle is going to be stored for any extended period of time.  Check with Coker to get their input for their tires. 
I have used the over-inflation method with great success on both radial tires and bias-ply tires (although the bias-ply tires always had a little flat-spotting in the spring).  I also try to roll my stored cars about 1-2 feet every week to avoid flat spots.   
68 L30 / M20 Convertible
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dd442

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Re: Flat spots on Bias-ply tires
« Reply #7 on: January 15, 2008, 03:20:07 PM »
He is right overinflating does work well but you still need to roll it around from time to time or put it on jack stands.
70 SS 396\350, 69jane, 69 442, 70 Mach 1

JohnZ

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Re: Flat spots on Bias-ply tires
« Reply #8 on: January 15, 2008, 04:22:48 PM »
If you put it up on jackstands under the frame with the suspension hanging at full rebound, the front upper and lower control arm bushings will deteriorate prematurely; better to leave it on the ground or use jackstands under the lower control arms so the suspension is still at normal ride height.

dd442

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Re: Flat spots on Bias-ply tires
« Reply #9 on: January 15, 2008, 05:51:47 PM »
yep i should hve been more specific. sorry

Pex68

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Re: Flat spots on Bias-ply tires
« Reply #10 on: March 31, 2008, 07:52:44 PM »
Forgot to say thanks guys!  Finally got to drive her around a few weeks a go and all was well after about 5 miles @ 40 mph & 36psi in the tires.

black79gmc

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Re: Flat spots on Bias-ply tires
« Reply #11 on: April 02, 2008, 01:20:19 AM »
My coker firestone redline F70 14s thump pretty good after car sits a few weeks,however it does clear up if you start using the car usually 200 miles will clear it up. my other car with goodyear polyglass F70 14 never thump no matter how long car sits,better tire. if storing car remove tires or raise car up on pump jacks.