I was looking for clamps that I needed for my Oculus Rift sensors and came across these. They are an add-on item so you’ll need to make an order of $25 minimum to have them shipped and reviews state they are pretty crappy when attached to a moving object. Even their promo video hows them setup as in a static position, but that’s perfectly okay if you need them just to stay where they are at.
Hopefully these help out any other Rift owners.
https://www.amazon.com/gp/product/B00GXTZYD0