After starting the season this year, we stranded 20 meters further with a big bang, and two broken ruthers. (both broke out the top end corner)

After getting two new rudder blades, I've mounted them, and wanted to test them. Closing the system is possible with a little force (then they are in "sailing mode") but when I want to test the capability of opening when running on the ground (putting force on the blades) they do not open, even with extreme force. (and now the force is again on the weak part in the top end corner)

Looking at the rudder system, I have the impression that either the springs are too strong, or the wheels are not the right size. Most probably it is the last option, because we changed some broken wheels last year. We inserted the black one, and have taken out smaller wheels. But according to the dealer the black wheels are standard.

In this picture the situation which does not work ok.



and this is how it was before (you can see the broken wheels which got out:



And this is the result of the system not working:



can anybody help me out, and tell from experience how the system originally looks like on the Nacra Inter 18?