tire pressure and wheel alignment

[Douglas Broome]

I recently changed from bias ply 650-13 tires to modern radial 185/80R13 tires. The specified pressure for the bias tires was 26 lbs. all four. Is there any technical data or hard experience indicating what I should use as pressure for the radials?

The alignment specifications are for original bias tires. Is there any reason why the alignment specifications should be changed? What is the basis for any recommended changes?

Thanks.

In the old days, when people were switching a lot of cars which came with bias tires to radials, it was usually recommended that the toe in be reduced to the minimum end of the manufacturer's recommendations for that model, because the stiff belt would cause excess scrub with the large amounts of toe-in which were often recommended for bias tires.

Since your tire sizes are close in terms of load capacity, the 26 lb. recommendation should be tolerable, but remember that it is a recommended MINIMUM, and all of us who love good handling, even in classic cars, tend to go up at least 4 pounds from what the owners' manuals recommend.