Question about activity after knee replacements

I was told no extreme sports like skydiving or para-sailing for sure....I would love to get on a regular bike again instead of a tricycle. Kneeling puts too much of a load on the kneecap and could cause a MCL tear or kneecap to crack, as weight is borne differently after TKR (structural change to the bone)...Glad you are on the mend!