Hi all,The main reason why really sidemount is not easy with a backmount twinset is that the harnass around your hips is completely different from a sidemount harnass. My backmount harnass goes way too high to be able to attach any sidemount tank proparly als sidemount, but it is easy to attach them proparly 'dir'.
I can attach them sidemount on my bm ccr as there I made d-rings on the ccr frame. The bungees are not that problem with a normal dir-harnass, but it is really the harnass webbing around the hips. The backplate end with me way above my hips, so getting it over my hips is impossible.
If a bottle is swinging around with a traditional stage rigging, then probably you have the boltsnap at the bottom of the tank too long, and the one near the valve too low. There is no need that a cylinder is swinging around.
When decos are rigged in a DIR way, I also find that they float around a bit and anyway they float enough to get a 90 degree angle when empty. I also think it is far from ideal and the goal of DIR philosophy is perfection.
Why not at least sidemounting them together (cross-fixing) on the left side ? I have no problem sidemounting my decos in a twinset configuration with a simple loop bungee and 1 Xdeep rubber Dring.