What's the bouncing ball for?
I figured out that I could reverse to enter the chasm, eventually, but was pretty confused for my first run. I refreshed probably 10 times and never started inside.
Once I was inside the chasm, the colliders were a bit janky. I'd recommend using a round shape like a ball or capsule for the bike collider and look into TrimeshFlags::FIX_INTERNAL_EDGES to prevent sticking on edges of the chasm.
It's pretty cool that the rapier debug collider aesthetic sort of works, actually.