Pitch and moveforward at the same time

I'm working on a project where a bike will be connected to a game.
You can cycle and you should move forward and up, and if you stop cycling you should slowly go down.

Is there a way I can easily add a pitch up, to a forward move
and a pitch down to no move?

ps. I forgot to mention, it would be great if it could be done by scripting only. tnx