Moving from Bias to Radial
 

I've read many of the posts on this subject but would like clarification.

I just purchased a 67 that has bias ply tires. When I drive the car it is over the road. The previous owner said the car was aligned but who knows.

Since I'm going to drive the car, I'm assuming going to 205/75-15 radials will help quite a bit with the way the car drives. At least I hope so as it's almost dangerous to drive.

My questions:

1) Is my assumption about improving the drive correct?
2) Is the wandering of the car because of the tires or could it be misaligned or both?
3) I've read that I will need to get the car realigned if I do go from bias to radials. Is this a must? In other words, if I put the radials on and it drives much better, do I need to get it done?
4) What's it cost to get it done?

Sorry for all the questions, this is new for me.

Ed

I have had both on my 65, and I prefer the bias ply......certainly not for the handling, but for the looks. That being said, bias tires can be a little exciting on an uneven road, or going over the steel grates on a draw bridge.......it feels like the the car is the driver, and your just along for the ride. I have gotten use to it, and it doesn't bother me any more. I won't even get into bias ply in the rain..... but too answer your question.....yes, If you go with radial tires, they will probably take care of your concerns.....but think of all the excitement you'll be missing out on. :D

Put them on, see how it feels, you will like it.
 

radials will be much, much better, new alignment will be difficult as you will have to have your own specs.

The pimply face kids at your retail suspension store will give you with dumb looks. You need a shop that has guys with gray hair. You will need your own specs going in, you can probably get suggestions here.

I would say add castor to maybe 7 degrees (others chime in)

toe, 1/16 to 1/8 total

camber 0 to 1/4 degree.

That usual wandering feeling is usually from lack of castor, i.e. the self aligning inclination of the upper to lower balljoints. A little more works will with radials

Plus how old are your current tires? remember that they have a 5-7year shelf life.

My questions:

1) Is my assumption about improving the drive correct?
Yes, it will be a totally different car that will be fun to drive

2) Is the wandering of the car because of the tires or could it be misaligned or both?
It's because of the bias ply tires
3) I've read that I will need to get the car realigned if I do go from bias to radials. Is this a must? In other words, if I put the radials on and it drives much better, do I need to get it done?
The only alignment difference is a slight adjustment in the toe-in. Not enough to really make a difference.
4) What's it cost to get it done?
A 4 way alignment is about $75 but save your money.


Put radials on it. I've run both. Bias ply tires suk and are inferior in every way compared to radials.:cheers:

Jim

If the car is correctly aligned to begin with, the only change that's necessary for radials is to re-set front toe-in; radials like zero-to-1/16" TOTAL toe-in (same for the rear - 1/32" per side).

Stock front caster setting is 1*-2* positive; more is better for straight tracking, although it increases steering effort at low speed. On most Corvettes, you probably can't get more than 4* or so before you run out of adjustment capability.

Put the radials on, have the front toe-in re-set, and see how you like it. While they're setting front toe-in, get a printout of what all the settings are for all four corners so you know what you've got as a baseline. :thumbs:

Wow!! That was fast and great advice. I'm going to order the tires today put them on and see how it rides.

Thanks again for all your great comments!!

Ed

If you don't have power steering, start exercising your upper body. Turning the wheel on a manual steering car with radials while parking can be a workout. Other than that, they're great.

Ed, as a final thought, run around 32-34 psi all around. Bill :thumbs:

Fortunately I do have power steering :) It took me almost 3 years of looking to find a 67 with PS, PB, and A/C.

Thanks!!
Ed

The difference is staggering. Driving on bias plys I could hear screeching going through about a 20 degree turn. I felt like I was literally driving a boat. I can't believe 65 Vette Dude prefers them. Guess he lives on the wild side!:willy:

If you don't know how to align (like me), call the tire shop and ask if they have the specs to align it. Mine did. I was having them put the tires on and an oil change, so its on the lift, whats another 60 bucks right? I didn't adjust the front toe in as stated above, but will do so next time.

One bonus to bias plies. SWEEET BURNOUTS!:cool:

Oh yeah, if you plan on restoring/doing NCRS type shows, you may want to bring the bias plies back home with you depending on what they are, since those are the original type tires.

No argument the radials will track a lot straighter on uneven surfaces. Radials require very little toe in the front/rear wheels.

If your car has been aligned for radials with little to no toe, the bias ply tires will run you all over the road. Guaranteed. Even with the correct toe, the bias ply tires will try to follow irregularities in the pavement. On smooth roads, no problem at all as far as tracking.

:iagree:

When I bought my 66 with 50K original miles, it had new radials, but felt sloppy/spooky until I; put new shocks on it, had it aligned, took the play out of the steering box, set it for quick steering, replaced the ball joints and all the control arm bushings. ymmv

needed to replace the springs front and rear too, before it drove like I expected it to.

Yikes! Well, I'll take it one step at a time.

When you say replaced, I assume you did not keep it stock? The reason I ask is because my car was restored to original NCRS standards (as far as I can tell) and I'm wrestling with changing anything to non-stock.

Ed

emdoller, I don't know how old you are, but having driven a '67 in '67 and now owning another '67, I can tell you that's how they handled in '67 too. Radials will help, but the culprit is the antiquated steering system. You will either get used to it, or you won't. If you don't, like I didn't, you might consider going to a new rack and pinion system. It is the best improvement I've made to my car, and I've made a lot. Yes, NCRS will go down the drain, but the driveability and fun factor will improve dramatically. Like you, I wresteled with changing anything to non-stock for years and just got tired of trying to make someone else happy, and then made myself happy. Good luck.

Thanks. I understand completely. I will swap out the tires and see what that does. If it's not enough, I'll consider the next steps. I was 5 years old in 67 but I have owned many cars from the 50's and 60's and nothing has ever driven like this. My 68 camaro that I drove to work today drives far better and it's stock with the exception of the wide radials.

Thanks again!! I'll reply when I swap out the tires and let you know.

Sorry but I disagree. I've owned many C-1's & C-2's both with bias ply tires and radials. There is nothing wrong with the steering systems on C-2's. The same system was used throughout 82 (well after radials were introduced). Even my 60 with antiquated king pins steers very nice with radials. The problem has ALWAYS been the tires.:rolleyes:

Jim

For a car you want to enjoy and drive, go radials. I didnt need to change anything...just bolted on the knockoff (bolt on versions) with the radials mounted....perfect and an outstanding improvement in handling. The "wander" is the bias plys following every crack and crevice in the road. Radials will eliminate almost all of that.

http://img.villagephotos.com/p/2002-...aug09forum.jpg

Wow nice white car !
Don't ever drive fast with ply tyres. Does anyone know why ply tires are so crap ! They have soft side walls. The steel belt in the side walls gives the tyre a stronger side wall so when cornering the forward inertia will allow the tyre to turn the car instead of rolling over and struggling to turn the car. Unfortunately ply tires to me look damn sexy ! I learnt the hard way and have spun the Vette on numerous occasions at low speeds in the wet due to rag tyres ! Get rid of them there not a drivers tyre. Stewy