To the left: The Bike Twist
Use your handlebars and saddle for a little bit of leverage to a twists. Inhale reach the crown of your head up the sky, lengthening your spine. Exhale deepen the twist from the center of your ribs, eventually including your neck (cervical spine) into the twist by gazing behind your back shoulder. Be sure to twist in the other direction, too!
Twists are great to flush out the spine and massage your internal organs. I also love to twist on bike during long stoplights.
It is basically downward facing dog, but placing your hands on your bicycle instead of the ground. This pose is a great one to do before or after you ride, since it stretches out the back of your legs, as well as helps counteract all that rounding in your upper back that happens when your ride.
Place your hands either on the top tube if you have a diamond frame; or if you have a step-through bike, like mine, you can place one hand on the seat the other on the handle bars. Walk your feet back until your arms are parallel to the ground. Take a peak at your feet to make sure they are hip-distance apart and your toes are facing forward. Breathe and feel the stretch along the back of your legs. Allow your heart the melt towards the ground. Feel your shoulder blades squeeze together. Below is another view.