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.

  • 4
    Welcome to Bicycles @aparente. I see that you are a member of Parenting and that you've already posted this to Sports. I would have thought each of those sites would be more appropriate than here. But we do have people here who do downhill. I'm sure they'll answer It's pretty safe, if you ... but if you spear yourself on a stick, fall off a cliff, hit a tree head first, etc then you could die. After all, the reason he gets a thrill is that he perceives danger.
    – andy256
    Commented Jul 30, 2015 at 1:52
  • 16
    The reason I think Parenting would be an appropriate place is that (as a parent) I totally disagree with this kind of wrap them in cotton wool parenting approach.
    – andy256
    Commented Jul 30, 2015 at 1:52
  • 4
    @aparente001: not necessarily, this could be considered an XY problem. Commented Jul 30, 2015 at 3:07
  • 5
    Strictly comparing the possibility of serious injury, I would regard downhill biking as more dangerous than downhill skiing, maybe by a factor of 2-4. That's just my thumb suck, though. Commented Jul 30, 2015 at 3:25
  • 5
    Wow. Culture shock. I think I was 5 years old (certainly in Kindergarten) when I first did downhill sking and I can't imagine my parents or any other parents here around (Switzerland) debating whether that was safe. We actually went on school excursions sking, and I can vividly imagine the mickey-taking which would have taken place should a child have been forbidden from coming along for safety reasons.
    – Nobody
    Commented Feb 9, 2018 at 23:27

8 Answers 8


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.

  • 3
    I agree with this. Ski/Ride within your limits. I skied from the time I was 8 to when I was 18, basically every weekend in the winter. Only once did I hear of a catastrophic injury (still survived) on my local hill. And it was because the person in question was doing something stupid. I don't think me or any of my friends even ended up with a broken bone. "Extreme" sports can be done in a safe way. There's no reason to stay away from them completely.
    – Kibbee
    Commented Jul 30, 2015 at 19:31
  • +heaps from me (long positive parenting rant deleted).
    – andy256
    Commented Aug 1, 2015 at 6:53
  • I agree with the comparison for the most part. My concern is that it seems to be easier to injure others when downhill skiing, specifically when an irresponsible person does it around others. That just seems to be harder to do on a bike, but skifields are covered in people who are not expecting a 100kph skier to lose control and run into them. For 90% of kids that's not even a consideration, but for the other 10%... barrell parenting is probably a better idea.
    – Móż
    Commented Aug 20, 2015 at 7:34
  • Depends where you are skiing. Some resorts have powder every day, nice soft landing, easy to top. Other have sheets of hard, blue ice more often than their advertising admits,
    – mattnz
    Commented Jan 30, 2022 at 6:56

You don't allow downhill skiing.

Downhill on same terrain bike versus ski.

You ski on snow. It is white and smooth. If it is not ice it is even soft. You bicycle on dirt and rock. Go down at 20 mph not even close.

Bike has less rolling resistance so you gain speed faster.

Bike has brakes and have to turn to stop on skis but I still say ski safer. You can lay down a two long edges on a ski. A bike on gravel does not have good braking.

Bike has handle bar to take out teeth and pedals that seem to find legs on the way down. Spinning tires.

As for knee you are way more likely to blow out a knee skiing. By nature of you have these long levers attached to to feet.

Back is not a common injury in a 12 year old and ski or bike you are not falling from a height.

I guess if you rule out scratches and bruises and make it knee and back only it may be close. Where do you put broken bones and stitches?

Me I allow both. There is risk versus life experience. A reasonable athlete that controls their speed is pretty safe with either. How your child approaches sport safety is a much bigger factor. In both you don't have another team that is trying to hit you like football. I would suggest that working with your child on decision making and risk will do more to keep him healthy than restricting him from these two sports.

  • I'd like to avoid fractures if possible, but sometimes fractures occur even at school -- there's never a money-back guarantee. Stitches I can live with. There may be a scar on the skin later -- that's not a big deal. ... Question about the teeth. Does the full face helmet do a good job of protecting against losing teeth? ... About skiing -- I've been told that when it's crowded, a snowboarder might suddenly appear out of left field and this type of dense traffic makes it more dangerous. The person who told me this explained why she had switched from downhill to x country skiing. Commented Jul 30, 2015 at 7:38
  • 1
    A full face helmet may protect your teeth (when worn properly), but it won't stop you from injuring or breaking your neck when your head hits something, stops and your body and bike continue moving forward. Commented Jul 30, 2015 at 16:13

Downhill mountain bike has the potential for very serious injury, that must be said right out of the gate. You can do terrible things to yourself.

I've ridden downhill for 15 years on and off, just recreationally, and I've had a few scrapes along the way:

  • separated AC joint in shoulder
  • hyper extended elbow
  • deep flesh wounds requiring stitches in legs (pedals mostly)
  • serious gravel rash (like all the skin off my tricep)
  • countless minor scrapes, bumps, bruises, etc

No breaks yet, and no other 'major' injuries, but I have seen many unfortunate outcomes. The potential for injury is very real and I'd go so far as to say you won't ride downhill without getting injured, it's just a question of how badly.

It really, really depends on the rider and the track. Some downhill tracks are easy to ride at the novice level, mostly smooth, well built corners, a few small features (jumps, drops, logs, rocks). The difficulty advances all the way to 40 foot jumps, steep chutes, very rough single track with braking ruts and holes and water bars, messy rock gardens with all manner of pointy bits, trees in close proximity, flat or off-camber corners that all but push you off the track, and very high speeds (50kmh or more). Stopping is a luxury not always afforded depending on the terrain.

Having said all that, riding within one's limits, you can ride for a long time without suffering any major injuries. I think downhill (like skateboarding) is an excellent sport for kids; you learn about risk vs reward, you get hurt and suck it up a bit and you develop advanced motor skills and coordination controlling a machine on a loose surface.

It's all about being in control, knowing the limits and pushing them slowly. Fortunately the more advanced downhill trails are scary enough that most people are more timid than brash, which is healthy!

Armor is important. A quality full face helmet is a must. Goggles keep the dust out of your eyes. Body armor is recommended (chest, back, arms) but you can probably get away with elbow pads. Wrap around knee pads (with side knee protection) or a knee+shin guard. Good tacky shoes for pedal grip, and gloves, mostly for grip - sweaty hands slip on the bars.


Not sure if this is still active, but i am 15 and can say from experience that skiing is much safer. I wouldnt suggest ski racing as that is dangerous, but i have been skiing since i was 6, and have never had a trip to the hospital or any injuries whatsoever. I live for the jumps and going fast through trees by the way. Meanwhile, on a bike, i was on dirt jumps (which are common in downhill) lost control, went off the the side and got scraped up pretty bad as well as very nearly getting a concussion (i couldnt see for a bit and my ears were ringing) Skiing is just that much safer as your feet are touching the ground and snow is soft, on a bike your feet are on pedals above ground and you are riding at high speeds on a hunk of metal/carbon on hard, rocky ground. I love both sports (i just do XC on a bike), but skiing is A) MUCH cheaper and B) safer for me. Just watch out for snowboarders.

EDIT I though about this more, and i have more points to add. For one, my brother who is basically crazy (He'll jump off a 60 foot cliff without thinking twice about it) rips down the mountain no matter how difficult the run is. He was on a steep double black when he hit a mogul wrong and then fell down the entire run (probably 10 seconds of rolling) he gets up, shakes himself off and keeps skiing. No injuries. I do not believe me or my brother have been injured skiing at all, and we ski drops, trees, jumps and all that fun stuff. When it comes to biking, my brother was attempting a bunny hop on a bike when his foot slipped and his shins hit the pedals. The bleeding wouldn't stop and he needed stitches. My brother never even really got into mountain biking (we only did stuff like skids and small jumps) yet still got injured. I think this really highlights my point of how much more dangerous biking is. The main benefit of biking must be just how much longer the season lasts and ease of access. In either sport, starting young and learning the essentials quick is really helpful.

  • You raise a good point. The trees. I have the impression one generally avoids downhill skiing near trees. Commented Oct 16, 2017 at 5:00
  • 1
    Fair points - do note that snow hides rocks quite well and they're unforgiving. Also, cycling is more useful than skiing in many parts of the world - I'd have to drive 2 hours to get to ski-able snow in the winter, but I can always ride. +1 for your input, and welcome to StackExchange.
    – Criggie
    Commented Oct 16, 2017 at 8:22

When considering only serious life changing or threatening injuries it is not possible to compare any of these sports. The risks are overall so low and depend so much on skill and situational risk that you cannot find meaningful sample sizes. Since risk is a purely probabilistic quantity it becomes meaningless.

You might consider the risk of an accident on the way to sports and of slipping in the bathroom. Both are significant when you consider risk in such a fine grained manner.

Speaking of health risks or benefits would be more worthwhile, eg repetitive brain injury from American football, knee injury from football.


DH Biking is considerably more dangerous than DH skiing, they are in totally separate categories of risk.

Surely, you can hurt yourself doing either; but DH biking you are moving much faster, have considerably less control, you are generally doing it in trees (i.e. rounded berms), you accelerate very quickly, you have a very large and hard contraption to jam into your body, you land in rocks and dirt, and the kinds of activities typically done (i.e. jumping berms) are more dangerous.

Most skiing is enjoyed on fluffy snow, in a wide area, wherein falling is a last resort means to stop and it's not bad.

Every single 'fall' in DH biking is painful: bruises, cuts, sores etc. whereas one can 'wipe out' several times a day in skiing and it's not a big deal.

DH biking done in trees (often) is exceedingly dangerous, one small rock, one small mistake - and you go head first into trees. It's a matter of time before you drive your head into one.

Consider that most DH bikers wear some kind of neck bace - I don't know of any other sport except car racing wherein that kind of equipment is used.

In terms of parenting, it's a very difficult choice. DH biking is simply not 'just some other sport' - it's a another level of risk. Personally, I simply wouldn't allow it. It's simply not worth the risk. I put it up there with fast go-cart racing, mid-size cars - it's just that dangerous.

Maybe there are some other activities that you son can develop such excitement for, perhaps competitive skiing might do? Everything below full DH is safe.


Downhill skiing is safer than downhill MTB because skiing has wider spaces, and that something touching ones MTB handlebars is both more common and worse than something touching a skiier.

For people reading this for the first time, as a former ski enthusiast and current bike enthusiast, relative risk is simple:

  • Ski runs wide, trees further away
  • Bike paths are narrow, trees close.

Almost every bike tumble I've had involved trees, usually hitting my handle bars.

If you're going to leave the ground I suspect they are both pretty dangerous.

I'd love to know how this all played out. I would expect a bubble wrapped, thrill seeker who has got a taste for downhill mountain biking will do it anyway but in secret and on their own terms. I know I would have.

  • Additionally, when skiing you want to stay away from trees because there may be voids under the snow, only held up by branches not more snow below.
    – Criggie
    Commented Jan 30, 2022 at 22:59
  • That's pretty much it. Obviously it depends on the skiers sense of self preservation since one can easily choose to ski near trees, but at least it is optional, especially when one is a beginner. Mountain biking doesn't usually offer routes without trees in close proximity to the path (at least not where I live).
    – David W
    Commented Jan 31, 2022 at 16:22
  • How it payed out -- we managed to keep him busy with other things and avoid ice hockey, downhill skiing, and downhill mtn biking. Fortunately the building of a special track where we were living either moved forward rather slowly, or didn't get publicity. We did eventually give in on lacrosse. (We were concerned about boys running around whacking each other with sticks but as it turned out my kid ended up running quickly down the field with his stick and the ball, so he wasn't on the giving or receiving end of any whacking. Commented Feb 5, 2022 at 19:50

I do both regularly, with my 11 and 13 year old. Without a doubt DH mountain biking is 100x (unscientific) more dangerous. You typically ski on a 50-100 foot wide trail, as opposed to an 2-3 foot wide trail. Neck injury is a big risk with OTB crashes, get a neck brace.

  • It was my question and I'm really not happy about the drive-by down vote. If someone doesn't think this makes a positive contribution to this page, let them use their words. Commented Oct 4, 2018 at 0:52
  • 1
    Aren't knee injuries quite common in skiing? I know people who can't run longer distances anymore because they had severe knee injuries from skiing. Apparently cyclists tend to break their collarbones, teeth or jaw.
    – Michael
    Commented Oct 4, 2018 at 19:41
  • @Michael - "cyclists" could mean anything -- anywhere from someone who rides their bike to go pick up a quart of milk, to mountain biking on mountain trails. Skiing has two drastically different types -- downhill and cross country. Commented May 2, 2019 at 13:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.