I think the weight distribution issue is a myth
with treeless saddles. I will not claim they are always perfect; but they
have worked for me without any problems of slipping or weight distribution
problems. Bob Marshall Sport saddles have designed the saddle to
distribute weight by a combination of where the riders seat, and thighs are,
plus the rigging AND stirrups are hung from a Y shaped webbing system that goes
to both pommel and cantle. People that might have problems are ones that
might two-point an entire ride, or ones that might just sit for hours. If
you ride with some posting, and post gently off your thighs (not slamming
down in the seat or stirrups), you will probably be okay.
Other brands of treeless saddles may hang stirrups
from a single strap that goes over the back of the horse; those brands I would
definatly avoid. Try to find brands that spread the weight of the stirrup
over the whole panel or split the rigging. Then again, English saddles
hang the stirrups off bars that come right off the front fork of the
saddle-ouch!
Keep in mind a saddle tree can only distribute
weight evenly if it REALLY fits the horse well. Between all the
mass-produced trees out there, and horses with poor back conformation; it's no
wonder you see so many horse with huge white spots (unfortuntaely even at
endurance rides).
Treeless saddles may not work with horses with
truly bad back conformation or really bad, unbalanced or weak riders that flop
hard on the horses backs....but then, very few saddles will work well
either.
Traditional saddles with trees can have problems by
being too narrow at the pommel and pinching, too flat in the bars and bridging
the back, etc, there are a multitude of problems that can occur. These
saddles won't even begin to distribute weight well. Even saddles
with flexible panels, another new innovation, will not work it the tree is too
narrow!
As far as slipping, I don't find mine slip, even
with a loose cinch and I can mount from the ground either side. I use a neoprene
cinch, not tight. I do not get on by pulling the saddle toward me, I have
one hand in the mane, the other arm across the back of the saddle, and step
up....
I will admit I once tried one of the early versions
of the Torsion. It had air bladders in the pomme and cantle. It
seemed very uncomfortable and bulky, and had no stability at all, really slipped
a lot.
Besides the mounting question (how *do* you mount
without the saddle twisting?) I wonder how good the weight distribution is
with a treeless saddle. I can understand the flexibility issue, but
wouldn't the poor weight distribution cancel out the benefit of extra
flexibility?