The Stovebolt Site Forums The Shop Area General Truck Talk rolling radius tire compairison

I was told by another "car guy " that if i want to keep the speed and handling of my '57 3/4ton that i would need to upgrade from my 17.5" rims dually rims to a modern 19" dually rim. Such as those found on a UPS truck. Is this correct ??

The tire diameter would be the deciding factor for speed, the wheel diameter more comes in to play for avaialbe tire sizes for a given diameter tire. It will also come in to play in handling by affecting sidewall hight and brake clearance. The guy you talked to is steering you the right direction, as most modern duallie wheels will not clear the rear brakes used on the older trucks.

Thank-you for the reply and the honesty, it will come in handy when making my tire decision, What would be your choice of rim diameter ?? and tire size ?

I would think that 19" tires would be easier to find than 17.5's, since so many motor homes have them. Another point is that with the taller wheel you can have a shorter sidewall and still have the same overall height, that helps the handling.

Thanks for the opinion,

One downside to a shorter sidewall is potholes. A taller sidewall will absorb more punishment without damaging the tire or rim.

so then tiny what tire size rim would you suggest ??

I'm not suggesting any certain wheel/tire combo, I'm just pointing out one downside to the modern big wheel/rubber band tire look that's so popular today. If you're going to spend a lot of money you need to be aware of all pertinent issues when making that decision. If a buyer lives in an area where potholes are common they might want to consider a different approach.

Speed and handling with an early truck are almost like oil and water, they just don't go together. (Unless you're BP) With a straight axle, leaf sprung truck, I would go more for the comfort side of things. I can't think that moving up to 19" rim would help handling much at all, especially if you're using a LT tire anyway. Most modern Dually trucks are still using 16" and 17" tires and they have more towing and load capabilities than any truck did in the past. I'd stick with 16" or 17".

Going with a 16 or 17 would be great, IF they would clear the drum brakes on the rear of the old duallie trucks. The older 1 ton trucks used larger drums that the later disk brake trucks do on the rear, 14" vs 13". On a single wheel aplication, you can get away with putting 16s on the rear (been there, done that), but a duallie wheel sits much further inboard. While I suppose a 17" duallie wheel might fit, a 19.5 will fit for sure. As far as tire size, 225/70/19.5 is only about 2" taller than the 8.00-17.5 that's oem for a '58 3800 duallie. The sidewall hights are less that 1/2" in difference, not engough to be noticable. Yes, the ride quality will suffer, more due to the heavier load range than sidewall hight. Handling may improve some due to the stiffer sidewall.
BTW, 19.5 were a factory option in single and dual on the 3600.

wow thank-you all for the information and advice, i believe i am going to stay with the dually look, may go with 17 or the 19 will depend on exactly what i see along the way., thank-you all again