[VAC] Re: TIRE Question/Vintage Jeepster tow-vehicle

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

Most Airstreams allow little room for "wide" tires, often there's not
room for what the tire dealers consider to be equivalent to the original
tires.

Tube type tires tend to leak air less, (especially important on rims not
made for tubeless tires), but when they flex the tube rubs on the tire
and the assembly can run warmer. There have been tubes for radial tires
but they are specially made to withstand the extra flexing of the radial
tires. 

Caster and camber are different slants to the wheels. Camber is whether
the top of the wheel is inside, above or outside the bottom. Caster
applies only to steered wheels and essentially is the relative position
of the ground contact with respect to the steering pivot, fore and aft
position. Caster is nearly always set so that contact spot is to the
rear of the pivots so the steering system tends to go straight. If the
ground contact gets in front steering tends to be unstable (twitchy!)
and generally tries to deviate from a straight course, getting worse
with wear.

Camber can lead to asymmetrical tire wear, though I suspect its most
often set with the bottoms of the tires in a bit so that when the axle
bends with normal load the tires are nearly straight up and down. Though
in steering often front tires tilt significantly.

The tire selection for the trailer and tow vehicle need to consider the
loads applied. Tires not rated for as much load as the tow vehicle will
not have long lives and will tend to not hold onto the road when
stopping or starting. Drastically oversize tires may not hold onto the
road well either.

I'm sure the original flat head 4 Jeep wagon engine was too small to
pull any trailer. It was too small for my dad's 49 wagon, would only
pull it to 50 in overdrive, 55 in straight high, and lasted only about
35,000 miles between major overhauls. It was a long stroke engine, not
make for the job it was trying to do. I don't know about the strength of
the drive train, whether it would handle a significantly larger engine
safely or not. But when one is changing engine and transmission, I
suppose fitting stronger axles is not significantly tougher.

Gerald J.