Safety comparison, downhill mountain bike vs. downhill ski My twelve-year-old recently tried downhill mountain biking when we were in Lake Placid. He found it thrilling and would like to continue with this new sport now that we are back home. I am hesitant for him to practice this sport on a regular basis because of safety concerns. We allow


basketball (with mouth guard)
soccer (with shin guards) 
swimming 
tennis 
cross country skiing 
ice skating for fun


We do not allow games with a stick -- ice hockey, lacrosse. And we do not allow American football or downhill skiing.

I'd like to be reasonably consistent with our existing policy!

Where does downhill mountain bike riding (on an established track at a reputable ski center) fit, on the scale of things? He has asked for a full-face helmet and elbow and knee pads, because that's what he was given to use as part of the fee at Lake Placid.

I'd like to avoid fractures, of course, but I'd mainly like to avoid really serious injuries and things that might leave him with longlasting health problems such as a knee or back that is never the same again.

I'm not worried about scratches or bruises.



Responding to a comment:


  This can't be answered without knowing the risk-taking behavior of your kid.


He is a risk taker and has a diagnosed problem with sensory integration (motor planning).

However, I personally think the question I asked can be answered without this additional information.
Having done both, I'd say they are about equally dangerous with the edge going to downhill biking.  

It's easier to gain momentum on a downhill bike and harder to properly lose it.  Additionally equipment failure is a bigger concern and generally more catastrophic.  Downhill biking in the winter pads the ground (like skiing) but, during all seasons, trees are an ever present danger.  Losing control and hitting an unmoving object at 30 mph will generally have a bad outcome.  

As a parent myself, I expect I'll probably downhill bike with my children at some point. As long as they work on learning control at slower speeds first and learn how fast and hard to press their limits they'll probably be fine.  Most of the injuries I have seen downhill biking have been with younger kids trying to ride way above their ability level.  The group of older guys I ride with are rarely (if ever) injured.  We generally ride right at our ability level and maintain control.  That being said, none of us are ever going pro.

In your situation, if you are just trying to maintain consistency AND have already decided downhill skiing is out (based solely on risk) then I'd say you should probably exclude downhill biking as well.