Andy wrote:
On Nov 2, 2:52 pm, glider wrote:
Why have dual axles when a single axle will do the job.
Is this a need for heavy two placed sailplanes?
I know twin axles are beasts to wrestle when pushing it around unless
you want to go forwards and backwards.
Dual axles seem to be relatively popular in the UK.
Someone out there must have some explanation.
GA
This was discussed June 17-19 this year under the topic "ASK-21 in
Cobra trailer single or double axle?". My reply follows:
1 axle is better IMHO because:
You don't need 2 axles for load bearing
2 axles = 2x the tires to worry about
2 axle rigs tend to push the tow vehicle around a bit more and can
have funky ride dynamics - especially for small vehicles - at least
in
my antiquated experience
2 axle rigs are a bit tougher to push around by hand
You generally have to pay for a second axle
The only consideration I can imagine is for extremely heavy gliders
(check the tire load limits) or potentially to keep from getting stuck
in very soft fields. Neither is a sufficient reason to justify all
the negatives. In the US they were briefly popular in the late 70's/
early 80's but quickly fell out of favor. You see almost none shipped
this way today.
The conventional wisdom in the USA is dual axle trailers are more stable
than equivalent single axle trailer for. They are not popular for the
reasons listed, and the tow vehicles popular in the USA are large enough
the extra stability doesn't have a high value. In the UK and other
places with typically smaller tow vehicles, I'd expect dual axle
trailers to be more popular, as GA observes.
Another reason that might apply in the USA, is most large gliders (open
class or two seaters) are normally left assembled and rarely trailered,
and the owner may have decide to just drive slower the few times he
trailers the glider instead of putting up with other problems.
--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "A Guide to Self-launching Sailplane Operation" at
www.motorglider.org