We have moved to silicone leg grippers (and indeed for all the grippers we use, for example on custom arm warmers). Silicone is great to use as it sticks better than rubberised elastic and also gives great stretchability so that it does not constrict.
For those who are not familiar with silicone, it is a band that runs along the gripper that will not slip on the skin, so preventing shorts from riding up. There are a lot of options available for silicone and one of the key factors is finding one that is durable when washed in washing machines (the cheaper ones will peel and crack). We went through an extensive test period with ours and we are confident it is the best available on the market in terms of comfort, funcationality and durability. We always welcome feedback, so if you have been wearing them, let us know what you think!