Here is my take on your situation. I started mountain biking at 61. I rode a lot of different trails crashed, got up, kept riding, and continued to push myself. I was also surfing so balance wasn’t an issue.
I can say that the amount of skills needed to do somewhat technical runs is off the charts. Even with decades of riding a road bike it is a completely different animal. The best I could get to was low intermediate. It is still a blast.
Mountain biking can be done at 71, but if you started 40 or 50 years earlier it will be a lot easier since you have established skills.
There are some similarities with surfing in that having decades behind me, I can still get out there at 70, but it might be different if I was just starting out at that age.
And like mountain biking there will be situations where you have to just go for it as being timid will only put you in a bad situation. That is the toughest part, putting the pedal down because hitting the brakes will only lead to injury.
John
Last edited by 70sSanO; 06-21-22 at 01:25 PM.