The new Atos V and the VX have most all of these tuning items already incorporated into the glider.
Straight trailing edge
It is not critical that the trailing edge Velcro match exactly, but when pressed together it must be straight with no wrinkles. I don't think Felix realized how critical this is or how differently various pilots pinch their trailing edge together. I first reported on this at Quest this year. It is amazing how little variations in the trailing edge can cause such a drastic change in the feel of the glider. After my report, Felix told me to make sure everyone knows to pinch their trailing edges together so the sail is flat, not bent up or down.
|The top velcro in this picture was pushed down to meet the bottom velcro, causing a wrinkle.||In this picture the trailing edge velcro was pushed together evenly to prevent a wrinkle and make a flat trailing edge.|
Wrap tip wand with foam tape
This works even better for the Stratos, since mine had slight wrinkles at the tip. Wrap the tip wand with 1/4" foam tape, don't overlap. This will increase the diameter of the wand and removed most if not all of the wrinkles at the tip. Both Felix and Alex did this to their VX's in Austria.
Put foam tape on the D-cell at the tip seam.
This will help get rid of the wrinkles in the sail at this point. The later model C's and all the new V's have this from the factory.
|You can just see the white tape under the sail near the seam||This is the other side where I have yet to install the tape. Notice the wrinkles.|
Bend the rib cams
You probably don't need this one if you don't have a lot of bar pressure like I did. You can bend the last three 7,8,9 down 1/4" to reduce bar pressure, bend them up if you don't have enough. This is preferred to putting the trailing edged together so as to cause a curve up or down.
|It does no take much.|
Extend stinger (move the tail back)
This helps a lot. Unfortunately we can not extend it as much as the V which is 35 cm longer than the C. Felix said we could extend it a maximum of 25 cm. This limit is because both the keel and stinger on the V are heavier than the C and extending the lighter models too far will cause tail oscillations at higher speeds. Felix says this helps the glide because it dampens the glider in pitch, which results in less energy lost due to pitch oscillations.
|If you extend your keel, make sure you add a second push pin as shown in the picture above. Without the second pin the tail can oscillate in flight.|
This takes a couple of special tools. The only shop I know that has the set up is Mission Soaring in Milpitas, CA. I'm not sure of the reason, but on my glider, most the left wing ribs were slightly out of adjustment. By making them all to factory spec, I was able to gain a performance. If you sight down the trailing edge from the keel toward the tip, all the ribs should be in a straight line, rising up slightly at the tip. If you see any rib that is out of line, it probably need adjusting. Felix says to look at this every time you set up your glider as you can see a rib that may be broken or has come loose from the spar.
Adjust free play of spoilers
Actually, tighten everything up a little, both the nose/spoiler (on the C model) wires and the amount the control bar moves before the spoilers deploy. Make sure that the spoilers deploy evenly and they both start at the same point in the control bar travel.
Update to new aluminum spoilers.
They really help with better handling and slightly better glide. They are more outboard on the wing and follow the shape of the wing better.
Change the flap rope from 3mm to 2mm.
If you do this, make sure you use something like Spectra that has very little stretch. Also, make sure you spray silicone lubricant into the flap rope channel in the down/base tube regularly.
Warning: Do not change the wing sweep out of factory settings.
The Atos C and V have a limit between 230 and 233 cm. See http://www.flyatos.com/wing_sweep_check.html for information on how to check the wing sweep. Contrary to some rumors, performance is not enhanced by changing the wing sweep beyond factory specifications. On the C and V models, the pulley geometry is dependent on proper wing sweep. One pilot at the 2004 Worlds change his wing sweep so that the pulley geometry did not work and had his control cable break, resulting in him deploying his parachute.