This was a question from my 6 year old. I didn’t know the answer and to tell the truth it had never occured to me.
Why don’t people wear seat belts when riding a motorcycle?
Nothing like ensuring your leg gets trapped under 4-600 lbs of sliding machinery. Not only would it get broken but also ground down.
ETA: It’s a rare accident where you would not want to be clear of the bike.
Minor nitpick. It’s more like 400-1000. Even a 600 pound bike is considered VERY light. I believe my current bike is 650 pounds and it’s a small bike.
I heard that motorcycle cops on the Autobahn have some sort of straps from their jackets to the bike, but that’s more to help them fight the wind hitting their body.
WRT to strapping yourself to the bike, I’d think you’d be better off skidding away from the bike in the even of a fall (you’d have less momentum that way). In the even of an accident where you fly off the bike (a high side fall) or rear ending someone, it might be better off to fly off it rather then flop down on to the ground with the speed that the bike flops over.
Having said that, I’ve seen motorcycle jackets with airbags built in. You strap something from the bike to your jacket that when pulled (as in you fly off the bike) it triggers airbags to go off. I have some ideas, but I wonder what they do to make sure you don’t set that off by accident.
Here’s a really bad youtube video
Here’s another version
If you search for motorcycle jacket airbag on youtube, there’s plenty of examples.
Minor minor-nitpick nitpick.
It depends on the bike. I’ve noticed that here on this board, many people like Cruisers. In my 200+ mile r/t commute (on commuting days, of course) I ballpark about 70% Cruisers, 20% Sports, and 10% Standards. (Casual observation, no actual counting.) Cruisers are indeed heavy. But my 2002 YZF-R1 weighs 430 pounds wet, and a YZF-R6 comes in about a dozen pounds lighter. I wouldn’t consider the R1 a ‘small bike’. It’s just not a Cruiser. 
Agreed. Your 150 to 250 pounds of body will bleed of its energy (Heh. ‘Bleed’.) more quickly than a bike that weighs two or three times as much. Also, riding gear is designed for sliding crashes. You might destroy your $1,500 racing leathers in a crash, but they’re designed to protect the rider at 150 mph – but not with a mass of metal attached.
Re: the high side. In a high-side, the rider comes off/over the top of the motorcycle. If the rider is attached, then he’ll go over the top and the motorcycle will come down on top of him. High-sides are hairy enough as it is. Best not to have a heavy weight falling on you to the mix (which might happen anyway).
It’s the difference between being strapped inside a box and being strapped to a hammer. A car body provides protection around the driver. A bike doesn’t, and it can hold you down or even hit you if you high side.
(On edit: you beat me, Johnny!)
You’re right. When I was shopping for my first bike I was only looking at cruisers, so I really have no feel for what a sport bike weighs.
I have a 2007 Honda Shadow, and looking at the specs, I was waaaay off. It’s about 500 pounds dry, so maybe closer to 550 wet (it has a liquid cooling system). Sitting there by itself, it looks like a nice sized bike, but park it next to a modest sized Harley and it’s pretty small. It would be dwarfed sitting next to a Goldwing or a Road King or Classic Glide which top the scales at nearly 1000 pounds.
Or even more simply put, it’s a good thing to be strapped inside of a steel box tumbling down the street. It’s a bad thing to be strapped to the outside of it.
Inside a car you have protection all around you. The seat belt seeks to keep you in the center of the car so that the shell around you takes the damage. There is no “shell” around you on a motorcycle, so there is no advantage—nothing to stay in the middle of. And many times you can help yourself by jumping away from the bike. Or by being thrown from it.
Some MotoGP riders have airbags built into their leathers. It seems that they are set off by a g sensor or something. There was a race last year, maybe Valencia, where Jorge Lorenzo nearly had a highside but managed to hold it together, his leathers had decided it was all over though and inflated the airbags.
People seem to be talking about higher speed collisions. In cars at slower speeds the advantage of the car isnt really the shell its also that the car ‘stops’ and stays level at lower speeds - it doesnt flip over or the like so a seatbelt can be useful even if theres no roof, and the seatbelt stops you putting your face into the steering wheel etc. On a bike, the problem is still there, the problem is reducing this risk increases the probability of other issues.
http://www.itechdiary.com/motorcycle-bmw-c1-e-with-seat-belts.html
They do actually exist btw.
What has been invented as more viable alternatives are airbags in the tank, which will come out to stop your face going into the front of the bike or the object you’re impacting. This does offer some benefits face protection wise, without having to risk trapping the person on the bike.
Otara
I’d have preferred to have airbags come out to protect my bike when I crashed. I got a bruise on my leg, but the bike suffered a few thousand dollars in damage. Of course, I was fortunate that my high-side wreck was at about 30 mph, if that.
I certainly would not want to be tethered to a bike that has gone down and is sliding across the pavement. Even the tethers on those airbag-jackets give me a creeping feeling - never mind the idea that I’d forget to disconnect/disable them before I got off the bike normally. 
Tell him they dont wear seat belts for the same reason that ultimate fighters dont wear seat belts - if they wanted to be safe, they wouldnt be riding a motorcycle.
Why do you think we call them: “organ donor machines”?
Think of a head-on collision at 40 mph between a guy on a motorcycle and another guy in a van wearing a seat belt with air bags.
Just what do you think is going to happen regardless of whether or not the motorcyclist is wearing a seat belt?
Although the comedy potential would be well worth it.
And your point is? (other then threadshitting)
I suppose you advocate riding a bicycle without a helmet as well. I mean, if you get hit by a car going 40, you don’t stand much or a chance, helmet or not.
Untrue. It’s simply that safety for motorcyclists - as also for ultimate fighters - is not predicated upon use of a seat belt.
:rolleyes:
Or as my aunt the nurse says, “Donor-cycles.”
And yeah, there no seatbelt for the same reason there’s no seatbelt on a saddle. If there’s an accident, you don’t want to be stuck to your “vehicle.”
My point is clearly seen by everyone else.
There is a definite reason why they call motorcycles: “Organ Donor Machines”
…and seat belts on a motorcycle wont change their enormous disproportionate fatality rate. Seat belts on a motorcycle is like lipstick on a pig. They are deathtraps…get used to it.
Actually, seat belts on motorcyles would change the fatality rate. They would make it go up. 
And no, they aren’t deathtraps. But that’s an issue for another forum.
.
Yes they are.
…and that is the answer to why there are no seat belts on a motorcycle - it is because it becomes pointless when you are riding a deathtrap.
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“Motorcyclists were 37 times more likely than passenger car occupants to die in a crash per vehicle mile traveled in 2007 and nine times more likely to be injured, according to NHTSA.”
http://www.iii.org/media/hottopics/insurance/motorcycle/?table_sort_739024=5
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"Single vehicle motorcycle crashes account for about 45 percent of all motorcyclist fatalities. More than 38,000 motorcyclists have died in single vehicle motorcycle crashes between 1975 and 1999. "