I got a recent question about what would be the best pull-up rig for someone who was going to be using it on a cement floor where they couldn’t anchor the rig. This person wanted a rig that would not move when doing butterfly pull-ups and would have a high enough anchor point for rings. He and his wife would both be using the rig.
My answer was an S3 with a Dirty South Bar cross member and side storage or base storage.
The height of the S3 would allow him to hang rings, while also having a lower pull-up bar that both he and his wife could use. loading his plates on the base storage, would keep the rig stable when kipping or doing butterfly pull-ups without having to anchor the rig to the ground. The video above shows how stable the S3 can be, even when not anchored to the ground.