rigger3006
Well-Known Member
ive got a chance to pick up 4 centerlines, the skinnies up front have ''bias ply only'' stamped on them. this is new to me, is there a reason for this and could you run radials on them?
need some info on centerlines
- Thread starter rigger3006
- Start date
-
I wouldn't. Radials and bias ply tires load the rims in completely different ways. If it says bias ply only, that means they weren't designed for radials. Here's an article from SEMA that explains why...
https://www.sema.org/files/attachments/WTC-2011-05-Bias-vs-Radial-Tire-Wheel-Fitment.pdf
And here's the short version, quoted from the article linked above:
Summary :
• The tire industry makes radial and bias tires that can be mounted on the same rims.
• Not all wheels and rims were designed for radial tires
• Construction features of radial and bias tires make them bulge differently when deflected
• The radial’s localized bulge puts more stress on the rim flange than a bias tire does
• Rim fatigue and cracking can happen to any wheel from normal flexing, cyclic loading, and cornering
• Radial stressing of the rim can accelerate metal fatigue and rim failure that is uncommon with bias tires.
• Failures will usually occur where wheel materials change direction (e.g., flange to bead seat, bead seat to well, well or base to wheel center, etc.).
• Evidence of cracking may be visually obvious or it may be indicated by air leaking
https://www.sema.org/files/attachments/WTC-2011-05-Bias-vs-Radial-Tire-Wheel-Fitment.pdf
And here's the short version, quoted from the article linked above:
Summary :
• The tire industry makes radial and bias tires that can be mounted on the same rims.
• Not all wheels and rims were designed for radial tires
• Construction features of radial and bias tires make them bulge differently when deflected
• The radial’s localized bulge puts more stress on the rim flange than a bias tire does
• Rim fatigue and cracking can happen to any wheel from normal flexing, cyclic loading, and cornering
• Radial stressing of the rim can accelerate metal fatigue and rim failure that is uncommon with bias tires.
• Failures will usually occur where wheel materials change direction (e.g., flange to bead seat, bead seat to well, well or base to wheel center, etc.).
• Evidence of cracking may be visually obvious or it may be indicated by air leaking
Yup. Those are the old style front runners. Not thick or strong enough for radials. The reason is, radials tend to squirm and sway more. That leads to more side loading than a traditional non radial tire.
If you look around the hub hole, you should find a production date stamped there also. Once you find that date, I'd call Centerline & ask if they will accept radial tires. The reason I say this is I bought a pair of 15x4 stamped for bias ply only. I called Centerline, they asked for the stamp date & said they would work with radials. They said that "some" wheels during an early production run were stamped incorrectly. I hope this helps you, good luck with your wheels.
I personally sold multi-hundreds of Centerlines with radial tires in the mid 80's. Even had product seminars with Centerline, they never warned us about mounting radial tires on the wheels.
This .. Been 10's in the quarter,& over 160 top end in a 3800 pound Olds Cutlass ,on these. Radials ,the whole time.Auto Drags,hold up just fine,for street strip use.... The date code post,has merit. Might be more related, to tire sizes .. (VW 165 sr15's,are a cheap tire choice ,here.. The early VW bias ply's,might cause issues,the newer radial versions,work well..j.m.h.o...)..
Yeah, some will hold up, some won't. And the one's that won't hold up might work just fine for years before the metal fatigue builds to the point that they crack or fail. 160 at the top end isn't a good time to find out your rims failed from metal fatigue because of additional side loading from radial tires. If the rim is specifically stamped "bias ply only" then it won't be strong enough for repeated uses with radial tires. Unless maybe it was mis-stamped as previously posted. But if it's truly a bias ply only rim, you shouldn't run radials on it because they stress the rims in completely different ways. Which is explained really well in the article I posted, if anyone bothered to read it.
pishta
I know I'm right....
I saw this on mine and researched it. Seems there was a post somewhere that said the bias ply rims were cast and the radial rim halves were forged. Dont know how true that was but it all boiled down to the different strength of the original rims. I have them out back and ran a conservative 15X8 70 series radial. Not a real barn burner. Dont know about extreme tires on them....
rigger3006
Well-Known Member
the front ones are bias ply only, the rears dont have that stamping, maybe i'll throw some pro tracs on the rear to match the fronts
rigger3006
Well-Known Member
just got off phone with centerline, they said no problem running radials, he gave me that answer even before i gave him mfg. date which is 1981.glad i dont have to put out more cash for new bias's.now to sell the m/t et streets off the rears!
Marcohotrod
Well-Known Member
all centerlines are forged
-
