A cyclist has been rushed to hospital with critical injuries after a collision with a kangaroo in Adelaide's foothills.

Emergency services were called to the scene on Norton Summit Road at Teringie about 8:45am, and the 52-year-old man was taken to the Royal Adelaide Hospital.

The circumstances of the crash are being investigated, and SA Health said the man's condition is considered critical.

The force of the impact was enough to snap part of the bike's frame.

Norton Summit Road is a popular route for weekend cyclists.

It was closed between Colonial Drive and Glen Stuart Road as Major Crash investigators attended the scene.