[VACList] New Tires and Wheels

["Helen Countryman" <helncoun@xxxxxxx>]

We are looking for replacement wheels for an Airstream Trailer.  I'll give 
some background on the subject, then some discussion of our plans, then 
some questions.

Background

Our trailer is a 1964 Airsteam Overlander, a 26 foot model, riding on four 
tires and wheels.  Tires are 7.00X15.  The wheels are split rim.  The last 
time we had a flat fixed we found it difficult to locate a mechanic that 
serviced split rim wheels.  The tires are over 25 years old, presumably 
due for replacement.  It appears to be time to get new wheels concurrent 
with the tires.  As the 7.00X15 is a high profile tire which is unavailable 
now, it appears appropriate to go to a 16" or 17" wheel to allow a tire 
size with the same diameter and similar width.

Tires on the trailer (set of four)

Dayton Thorobred Super EMT    nylon cord

8 ply rating (equivalent to Load Range D)

Spare (not originally with the trailer)
Goodyear Travel Trailer Hi-Miler    nylon cord
Load range C
These are bias ply tires.  Wheel for the spare is not split rim; checking it 
with a caliper shows rim width to be 6 inches.  Rough measurements on 
the split rim wheels indicates a rim width of either 6 or 6 ½ inches.
Wheels are six lug, 5 ½ inch bolt circle.  Gauge of material and 
construction give the appearance that they were designed for a load 
capacity of somewhere in the range of 2,000 to 2,500 pounds per wheel.  
Wheels are black, with 'Baby Moon' hubcaps.
I found some old specifications for 7.00X15 radial ply tires.  Presumably 
these approximately match the bias ply for load capacity and physical 
size.  The dimensions seem to match what I measure on my tires.
Overall Diameter                                                   29.4 to 29.7 inches, 
depending on manufacturer and series.
Section width on 6.0 inch wide rim                    7.8 to 8.2 inches
Tread width                                                           5.8 inches typical
Load capacity per tire
load range C                                                          1720 lbs
load range D                                                         2040 lbs
Of current (i. e., used on a significant selection of 2003 light trucks) light 
truck tires the one which appears to come closest for sidewall width and 
overall diameter is the 225/75R16.  Typical characteristics are:
Overall Diameter                                                   29.3 inches
Section width on 6.0 inch wide rim                    9.1 inches
Section width on 7.0 inch wide rim                    9.5 inches
Tread width                                                           6.4 inches
Load capacity per tire
load range C                                                          1966 lbs
load range D                                                         2335 lbs
These seem to have become a de facto standard for 'one ton' light trucks 
with dual rear wheels.  I expect that they would also be common on 
smaller motor homes with dual rear wheels.
The trailer wheel wells appear able to accommodate tires with sidewall 
widths up to approximately 10 inches maximum.
Plans
Pending response to this inquiry, I'm planning to get a set of four 16 inch 
wheels with 7 inch wide rims and a set of four 225/75R16 tires for our 
trailer.  I've selected the 7 inch rim because it has a better offset for 
fitting the trailer's wheel well  -  in fact, the same offset as the current 
wheel.  I. e., track will be unchanged.  Wheel will be ordered black 
(powder finish), with baby moon hubcaps from the same supplier.
If this all works out well, I plan to write a technical article discussing 
this subject and including specific supplier names and part numbers, and 
offer it for publication to 'Vintage Advantage' and 'Blue Beret'.
Questions

1.             Has anyone else done this type conversion?  If so please 
comment on results, wheel supplier, type, P/N, size, hubcap supplier, 
P/N, tire type and size, etc.

2.             Is anyone interested in having the old wheels and hubcaps?  (If 
so, you need to be available in South Everett, Washington to pick them 
up when I get them replaced.)

3.             For the technical historians out there  -  when we got the 
trailer the tires looked only a few years old.  Many years later they look 
much the same.  They've aged very well.  So:  in 1964, did Airstream use 
Dayton Thorobred Super EMT tires as original equipment on some of their 
trailers?  (Our trips have tended to be infrequent and usually moderately 
short.)


Lauren Countryman
23352
helncoun@gte.net