Fizik tundra m5 mag mtb saddlethe tundra is 1 of fiziks 3 spine concept mtb saddle shapes of these 3 the tundra shape is flat narrow and long tundra m5 is for the snake flexible spineif you are very spinally flexible far less than 90 degrees between your straight legs and your back when bending over as far as you can keeping your legs straight a shoulders width apart you are a snake you achieve the performance position using your spinal flexibility alone not rotating your pelvis a