Nope no race yet PB!
I looked at that ball chair for awhile too.
I ended up just getting a regular Giaim balance ball to sit on but it
hurts my back too.
My new chair is hurting me too, so the owner of the company that manufactures the chair is driving out with 3 others for me to try or to custom fit to me.
AMAZING that he would offer to do that!!!
So til then, I'm back in my cheap but comfy Office Depot ergo chair.