Not sure where this "no bike rack or spare tires on bumpers" got
started, but maybe I should start an "Airstream urban myth" section on
the website. It may have sprung from the waste tank induced frame
separation problem of the longer trailers in the mid 1970's, but it is
safe to say that if you attach a spare tire (as Airstream did) or a bike
holder to the frame portion of the rear bumper, and the trailer is in
good unaltered condition (no extra tanks, heavy cabinets, etc), under
normal driving and loading conditions, you will do just fine. The only
trailers I'd be leery of are the 1969-1978 28'+ trailers without the
Service Bulletin mod and any of the 25'+ 1950's/1960's single axle
trailers. 1940 Centerpole trailers are excluded of course. Much of the
"frame separation" encountered on trailers is actually the result of the
C channel detaching from the floor plywood due to water leaks/rot. The
whole backend can then flex up and down if you stand on the bumper.
I'll find some way to sum this up in the FAQ's one day.
Best of luck,
RJ
VintageAirstream.com