On Thursday, February 2, 2017 at 7:58:01 AM UTC+3, Sierra Whiskey wrote:
I like the explanation of "Club Class" on the FAI site:
"The Club Class arose to provide international level competition in club-type gliders for the large number of talented pilots who could not aspire to owning an expensive modern glider of their own. It has kept demand high for a number of older but still very valid designs."

Of course the term "Expensive" is relative, but the current US Club Class list spans roughly $10,000-$80,000 where the FAI list is much narrower.

My Two Cents:
If the handicapping of gliders were quantifiable through the use of a formula that accounted for the performance of the glider in order to actually level the playing field of the aircraft and allow for a measure of the pilot then the introduction of modern gliders to the class would make more sense. Correct me if I am wrong, but for over a decade the US handicap system has been more of an arbitrary assignment than a calculation.

I look at the Std. Cirrus compared to the LS-8. Their US Handicaps respectively are 1.0 and 0.915. To me this would imply that the LS-8 is 8.5% "better" than a Standard Cirrus. (Better is not the best descriptor, but is meant to be a summary of glide performance and speed).

Lets assume that the two gliders mentioned above are flying at Best L/D.
LS-8: 43:1 at about 50 kts
Std. Cirrus: 36.5:1 at 50 kts
I calculate the difference in performance by looking at a multiple of the GR*V_(L/D). Since in this case the V_(L/D) is the same we can omit them, and just compute (36.5/43) which gives 0.849.

The numbers above are a bit crude because they are pulled from various sources online. Even the LS-8 data is "Calculated" and the tested data is slightly different. Looking at it from other sources:
LS-8: 43:1 at about 50 kts
Std. Cirrus: 38:1 at 50 kts
This still gives the LS-8 an advantage of 0.884.

In a final "base" example I will use some extreme numbers, degrading the performance of the LS-8, and exaggerating the performance of the Standard Cirrus:
LS-8: 42:1 at about 50 kts
Std. Cirrus: 38.5:1 at 50 kts
We finally arrive at an advantage of 0.917! (I take this as a "Factory New Std. Cirrus" flying against a "Buggy LS-8 without Gap Seals"?)

The above examples would be great if we flew contests while flying at Best L/D speed over three hour courses of 150 miles. The fact of the matter is we are frequently pushing MacCreedy "2" speeds on four hour courses that exceed 240 miles. (Let's compare the performance at 60 kts)

Since I don't have either of these factory polar curves to use, again, I am coming up with crude numbers, but I still think they speak volumes. These are a comparison of the L/D at a constant sink rate (2 m/s):
LS-8: 24:1 at about 92 kts (92*24=2,208)
Std. Cirrus: 22:1 at 86 kts (22*86=1,892)
Now we have a performance comparison at a more representative cruise speed in competition with a yield of 0.857 in favor of the LS-8. This means at a target MacCreedy speed I would expect the LS-8 to perform roughly 14% more efficient than the Standard Cirrus assuming the exact same pilot in the exact same point (Position/Altitude). This seems to be quite far from the 8.5% advantage given by the current Handicap List.

Does anyone have any information on how the current US handicaps are derived? I would really like to see what performance numbers were used to calculate the level playing field numbers that we currently use.

Thank you for any help or pointing me in the right direction! Only one of my calculations even come close, and it seems to be an extreme example!

BGA has them at 90 and 100, so 10% or 11.1% different depending on which way you look at it.

The problem with these is one number can't apply across all conditions, especially with gliders so far apart in performance and generation.

On strong days, the LS8 is obviously going to run away into the distance and win a three hour race by far more than twenty minutes.

But on a weak day where you can barely stay aloft and the thermals are weak and narrow? It might be a lot closer, maybe even close to equal.

There probably exist days when a Ka8 can beat an LS8. Not often, mind.