Knowing this was a couple months ago but for possibly future reference:
This is an ulnar gutter circular cast. Next was, apparently, an ulnar gutter backslab (synthetic type) but that’s not a strict protocol. It could have been a backslab from the start, whatever material, as the purpose is to immobilize in the correct position in a fool-proof way and the material used is irrelevant.
After this, almost certainly, would be a removable splint - patient is allowed to remove it to shower, possibly sleep.
No way you were advised you could safely race. Were it a finger, sure, probably with a dorsal finger splint but on your own risk as any fall had the potential of catastrophe. This? Even handlebar vibration could F you up.
And pain isn’t a reliable indicator of anything relevant here. Surely your consultant surgeon would advise/advised you regarding this.