http://www.willswing.com/pdf/pdf_man.asp?theModel=T2

You will find that the pitch trim of the T2, as well as the
basetube position at trim, changes with VG setting. At VG loose, the T2 will
normally be trimmed very close to stall, and may even be trimmed below the
minimum sink or minimum “sustainable” speed (trimmed partly in a mush). The bar
position at trim at VG loose will be relatively far out. As you set the VG
tighter, the trim speed will normally increase and the trim bar position will
move back. On a competition tuned T2 with a Mylar sail, the trim speed at VG
full tight may be as high as 30 mph or more.

At tighter VG settings, the amount of pitch pressure felt as you move away from
trim also decreases. At VG loose, the pitch well is very defined, and the pitch
force increases quickly as you pull in from trim speed. At tighter VG settings,
the “pitch well” becomes more “shallow,” and the pitch force increases much less
as you pull in from trim speed. At VG full tight, the pitch pressures when
pulled all the way forward may be as light as 2 lbs per hand.

Overall pitch trim is affected by several factors. Among the most significant is
the location along the keel of your hang point (commonly, if mistakenly,
referred to as your “CG location”). The farther forward your hang point is, the
faster the glider will trim, the less effort will be required to fly fast, and
the more effort will be required to fly slow. If the glider’s trim is too slow,
it will make the glider more difficult to control in roll, especially in
turbulent air and when the nose pitches up on entering a strong thermal. For
this reason, you may well find that it is easier to thermal with the VG set
between ¼ and ½, as this will speed up the trim and make the glider less
subject to pitching up in thermal gusts.

On the T2, hang loop fore and aft position is adjusted by repositioning the
elevated hang bracket on the keel. The bracket is secured by a bolt a through
the keel. On early model T2’s, there are three holes in the keel and two holes
in the bracket to allow six positions in increments of ½” over a range of 2½” of adjustment. On later models, there is one hole in the bracket and three
holes in the keel at intervals of ¾” to allow for three positions in increments
of ¾” over a range of 1½” of adjustment.

Note that the bracket on early models, and the base saddle on later models, are
front to rear asymmetric – providing more support to the rear. Do not mount
either the old style bracket or the new style saddle in the reversed position.

We recommend that you not stow your glider bag, or any other cargo on the
glider. The practice of putting your glider bag inside the sail, for example,
can drastically alter the pitch trim and static balance of your glider, and
adversely affect its flying and landing characteristics. The best place to carry
your glider bag or other cargo is in your harness.

Another factor that can affect pitch trim is the adjustment of the keel pocket
rear support strap. If this strap is too tight, it can significantly slow the
trim speed, to the point where the glider is difficult to fly. With the glider
fully set up on the ground, and the VG set full loose, there should be some
slack in this strap.

Finally, the adjustment of the sprogs will affect pitch trim at tighter VG
settings, although not at VG Settings looser than about ⅔. If there is
excessive “transient trim” (increase in trim speed at tighter VG settings), it
is an indication that the sprogs are set too low. If there is a marked reduction
in trim speed between VG ⅔ and VG tight, it indicates that the sprogs are set
too high. When the sprogs are set properly, the trim speed will normally
increase at least up to VG ¾, and will not be significantly higher or lower at
VGT than at VG ¾.

In the absence of the use of tufts, it has become common for pilots to talk
about bar position, or about indicated airspeed, when trying to communicate how
to trim a glider properly or how to fly a glider at the proper speed for a given
situation. The problem is that these methods are unreliable and inconsistent
from one pilot to another even on the same glider. The angle at which your
harness suspends your body in your glider has a great deal to do with your
perception of the bar “position” relative to your body. Airspeed indicators vary
in their indicated airspeed depending on the make of the instrument, its
calibration, any installation error, etc. The use of tufts gives you an absolute
first hand indication of the actual aerodynamic event associated with two
critically important airspeeds on your glider. It is a potentially useful tool
that may improve your flying.