I am so pleased you are feeling better, Gus!
I think the little and often is the best way to go..trying to keep the level steady.
Perhaps you can try the dispersible Madopar again to rescue you if you need a boost, just take when you feel the need up to three times a day in addition to the Sinemet regime.
My husband also rides his bike to keep up muscle tone...
It really is a case of experimenting until you find out what works best for you.
Hopefully the new Rytary tabs will mean the 2 hourly dosing can be lengthened..
Our neuro is looking into when it will be available here.