If a rudder cable should break in flight, what can you try, before hitting the silk? First off, fly the sailplane. You should be able to keep the wings level by fighting the uncommanded rudder input with opposite aileron. Let's assume the right rudder cable broke and the left pedal spring has pulled in full left rudder. If you can get hold of the rudder cable, you may be able to pull on the broken cable and cause the rudder to come back to center.. Pull forward on the right rudder cable or aft on the left rudder cable. I don't believe this is a viable solution in most ships because the rudder cables are inside a nylon sleeve and not accessible in flight. What else could you try (while holding right aileron to keep the wings level)? The problem is the left rudder pedal spring is pulling in unwanted rudder, so how can we get it to stop doing that? Try and get your left foot over the left rudder pedal and pull aft on the top of the pedal with the heal of your left foot............not likely, I hear you saying, but what if you pull the rudder pedal adjustment all the way back? That might get the pedal close enough to get the heal of your left foot over the pedal? If successful, pull it all the way back, this will relieve the spring tension that is applying the unwanted rudder input. Home free, right? Well, maybe just pretend your Joe Cessna driver who doesn't use the rudder much, anyway!
What do you think?
JJ

One more little 'tid-bit while we're talking about the rudder cables..........if you don't like the angle of your pedals (most stand too straight up for my liking) you can lean them both forward by simply adjusting the length of both cables. Install a 1" steel carabiner where the cables end forward of the rudder pedals. Sound crazy, but it's true!
Be sure to check that your new pedal position, still giver full rudder throw!