Vac Head Question

I have a fairly new in-ground vinyl pool with a deep end. The sides go straight down about 4 feet, and then slide down to the deep end at an angle to 8 feet.

The problem I am having is the vac head does a "wheelie" when I try to clean the slopes on the sides. The front comes up and the back scrapes against the liner. I tried two different vac heads (the triangle and the half moon) and they both do the same thing. Both weigh about 5 pounds too.

I seem to remember seeing a vac head a while back with a tension spring on the pole connector, that forces the head to stay down flat on the bottom of the pool. Does anyone know of one like this, or have any recommendations? The only one with a spring I was able to find is a gunite one with the wheels.

Thanks