At 06:15 14 December 2016, Tim Taylor wrote:
Most modern 18m were optimized for 18m, but but can fly well as 15m. The
on=
ly weakness of the 18m in 15m is they are heavy. Most are 100 to 150
pounds=
heavier than a pure 15m glider. The 29 does well in locations with
strong=
er conditions, but suffers on very weak days. The motor versions are at
a
=
significant disadvantage in lighter lift. On the other side they do
bette=
r in very strong conditions with significant cloud streets. =20

It will be interesting to see the next generation of 18m and 15m gliders.

=
=20

I still prefer a true 15m glider with empty weights at 520 to 560 pounds
ov=
er the much heavier wings of the 18/15m gliders.

Interesting observations Tim. I too fly a 27 against 29s at 15M
competitions and would say that turbo-less 29 versions are at least the
same if not better than the 27 in weak conditions because of the lower wing
loading. Tim Scott's 29 is only a few kilos heavier than my 27 in 15M
configuration.

However the 29 can achieve a greater weight and wing loading than the 27
for good conditions but has a greater wetted area which probably makes then
equal at high speed.