Triathalon

[DocPop 1]

I believe it depends on the exact canopy you are flying but the theory is that, particularly with a tailwind, using some brakes decreases your sink rate and therefore gives you a longer canopy ride during which to cover the ground.

Rears may be better than brakes on some canopies. The advice I was given was to try both and use the accuracy trick to determine which is helping more.

Personally I use brakes because rears are so effing tiring!

"The ground does not care who you are. It will always be tougher than the human behind the controls."

~ CanuckInUSA

[Hellis 0]

ok.
GPSdata from a canopyride. numbers are in Km/h and meters.
As you can see i first fly at full speed, then apply rears, and let go again.
There is some difference in horizontal speed but looking at the vertical speed, its totaly worth it
Please note that the GPS skips data at some points. At row 12 you see a vertical speed of 60, thats because the GPS skipped 4 seconds.

[yeyo 1]

Just 2 days ago I was coming downwind from a long spot after a jump with my brother. He flies a Stilleto 120 @ 1.5 and a fly a Triathlon 150 @ 1.33.
He was about 200' ahead of me at the same level, he has using rear risers and I was using 1/4 brakes and we were keeping the same distance and level. So use whatever works for you!

And to stay on topic...I love my Tri

HISPA #93
DS #419.5

[Ronaldo 0]

Quote

But I always thought that deflecting the tail also decreases forward speed, thus the glide ratio suffers, whereas using rears only flattens out the glide and doesn't slow the forwards speed.

This isn't my area of expertise, can anyone present some scientific info ?

I believe it is due to the changes in airfoil shape. Without any brake or riser input the airfoil has basically a flat/ convex profile or camber (much like a Clark-Y airfoil). When you apply light brakes or rears you change the profile into a convex/ concave airfoil which produces higher lifts (and higher drags). If tail deflection is light and the airfoil is not brutally distorted, the gain in lift coefficient (CL) surpasses drag coefficient (CD) increase. Take these airfoil examples at 0º of angle of attack and Reynolds=100000
Clark Z (no tail deflection): at 0º CL=0.5 and CD=0.03
http://worldofkrauss.com/foils/781

FX 73-CL2-152 (1/4 brakes or rears): at 0º CL=1.3 and CD=0.03
http://worldofkrauss.com/foils/753

Comparing both airfoils we can see that the convex/ concave shape produces much more lift for the same amount of drag which would lead to a better glide. Obviously a parachute would not have the same smooth curved shape and the gain wouldn’t be as good but possibly high enough to make a difference.
When you apply deep brakes the airfoil is severely distorted and drag wins the battle decreasing glide

Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

[likestojump 3]

God Damn Ronaldo ! That's as perfect of an answer I could have expected.

thank you.

[Ronaldo 0]

Thanks Paul, just one correction in the above example: CD for the Clark-Z would be about 0,015 instead of 0,03. Sorry, it was very late and my eyes were not as sharp
Still it is a much higher CL/CD ratio for the FX 73-CL2-152

Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted