On 5/16/21 11:14 AM, 2G wrote:
On Monday, May 10, 2021 at 8:23:04 AM UTC-7, AS wrote:
Snipperoo...

Trailers are designed with tandem axles because one axle can't
carry the load of the trailer, not to provide greater
stability.
I call 'hog-wash' on this one! There are a few trailers by the same
manufacturer with the same glider inside in the exactly the same
configuration but they have a single axle with larger wheels. The
load bearing capability is the the same in both cases. Going to a
tandem axle enhances stability (tracking) and allows the whole
trailer to sit lower since the wheels on the tandem axle are
typically smaller. Lower CoG = more stability. I completely agree
with your point of them being a pain in the butt to man-handle
them.

Uli 'AS'

The tire scrubbing that does occur during turning (no one seems to
dispute that as it is obviously true) cannot "enhance" stability; the
trailer is literally fighting being turned by the tow vehicle. If
this were the case then adding even more axles would make the
trailer even more stable. Trailers, or vehicles, with many axles
(transporters) articulate the wheels for this reason.


Well, hey - since this thread began with discussing a glider-trailer
towing topic, better into the thread-drift weeds than verge weeds, I
suppose...

I am not a professional trailer designer nor have I played one on
TV...but I've delivered manufacturing-componentry-parts to a dozen (or
so) of 'em in my engineering retirement. I'll bet my retirement slush
fund that multiple reasons exist for quantity-of-axles choices for a
given trailer design, trailer/axle carrying capacities *generally* being
near the top of the list.

As for trailer stability, it'd be difficult to get a more stable trailer
than one with infinite rolling-resistance drag. Or any other kind of
drag, for that matter. I am, of course, assuming that keeping the CG of
any towed trailer behind the towing vehicle while said vehicle is moving
forward, is desirable...

I'll further bet some of my retirement slush fund winnings from above,
that the somewhat-implicit assertion of the final sentence of the above
snippet, is "debatable" (as in, the sweeping claim made, is far from "an
absolute, given, fact") - with the desire for increased stability (or
its lack) *not* being at the top of a designer's list of rationales for
incorporating steerable trailer tires.

YMMV.

Bob W.