I have heard that the severity of injuries tend to decrease while riding a road bike at high speed. An instance of high speed would be like those in the Tour de France.
The reasoning behind this idea is "enough" speed allows the cyclist to "roll" upon landing thus decreasing the chance of breaking bones for example.
This seems contrary to my basic knowledge of physics and momentum, so, is it true?
In "Epidemiology of bicycle injuries and risk factors for serious injury" by Frederick P Rivara, Diane C Thompson, and Robert S Thompson, the authors gave a questionnaire to 3,390 bicycle riders who had attended a hospital emergency department in the Seattle area.
They found that cyclists involved in a crash at a speed greater than 15 miles per hour were 1.4 times as likely to have a "severe" injury (defined as an injury severity score greater than 8) as cyclists involved in a crash at a speed of 15 miles per hour or less. The 95% confidence interval was 1.0 to 1.9.
(Caveats: 1. It seems strange to me that the authors only reported odds ratios, when they apparently had the data to compute effect sizes too. 2. The fast cyclists differ systematically from the slower cyclists: the odds ratio fell to 1.2 when other factors in the study were controlled for. 3. It's Rivara, Thompson and Thompson.)
As far as I know, in any vehicle, there is a direct relationship between speed and severity, statistically speaking, with "lots" of studies showing that. This also applies to being hit, or front-to-front crashes. There's even the term "high-energy-trauma", applied by health professionals to injuries involving high energies, for example high kinetic energies.
Of course there are confounding factors: are fast riders (professional riders?) more skilled? Are fast racing events the place for a more "focused" riding? Do they fall less, or are someow more prepared to fall?
Anyway, I cannot see how a SLOWER fall could hurt MORE than a fast one. It's a matter of kinetic energy, speed of response of human motor coordination, even common sense.
Although I have not evidence to bring about, I hope this helps someway.
It is totally dependent on the impact. If you run into a wall you want to be going slower. If you hit a bump and are launched off your bike or jump off a cliff you want to be going faster. I don't know physics well enough to explain it that way but I do ride a lot of street (jumping down stairs, off roofs, etc.) so I will explain it how I know you want to land in that sense. Think about the angle of impact jumping off a loading dock, if you drop going at a slow speed you will impact the ground almost at a 90 degree angle, your body will need to absorb almost all the impact (on a non-suspension bike). If you go faster you will impact the ground at say 45 degrees, you will feel a lot less impact on your body.
Taking that to the tour de france (or crashing in general, even on a jump), if you roll rather than slide, your impact on the ground will be a lot less at higher speeds, your chance of twisting a leg or whatever is less because your limb doesn't have time to get planted. It might help to watch some parkour, they will roll out of a jump because they are trying to transfer the impact at an angle against the ground rather than absorbing an impact perpendicular to the ground.
I think there is likely no clear answer. The points go both ways.
Yes at speed there is the ability to roll. But also the risk of trauma with a stationary object. Be it an object or the ground. Humans are soft and squishy with fragile bones compared to concrete and asphalt, rocks or trees.
Those who can and do ride at higher speeds are generally fitter, often younger, and more able to bounce back from an injury.
These speedy types have learned to be situationally aware, and are more alert to their surroundings and the proximity of obstacles. When I noticed this when riding quite fast on an ebike... I was looking around a lot more and riding much more defensively so if an obstruction were to appear, I already knew where my runout spaces were.
Having had one significant-speed whoopsie myself that was caught on camera, I can say that perception of time really does slow down when its all going badly. Perhaps thinking "this is gonna hurt" is the key.
ive read every answer here. and none of them reflect actual experience riding a bicycle and getting into multiple accidents on them. i have. i have also SEEN multiple accidents happen.
RIDING ON CITY STREET IN MANHATTAN AND BROOKLYN ; the reality is that the biggest determining factor of how bad your injuries are is HOW YOU FALL OFF YOUR BIKE AND WHAT YOU FALL INTO. it is that simple.
and for this reason, my experience reflects the fact that that higher speeds ensure you fall off your bike in a manner that is FAR LESS CONTROLLED AND MORE SLOPPY. thus, higher speeds ensure your 'fall' is worse, which is entirely the opposite of the thesis that your fall is better if you are faster because you can 'roll'. thats utter nonsense.
if you are going at a slower speed you have a few more microseconds or milliseconds to adjust your body and torso and DIRECTION of your fall. in particular, you put your hands out in front to shield your head, and reflexively try and protect your head. apart from those reflexes, you control the 'wobble' of your bike in a fall that doesn't occur smoothly--many falls occur due to a GRAZING of the bicyle hitting something from the side lightly, including pedestrians, a light knock from a car, hitting a hard pothole, sliding over leaves or a grating that destabilizes your balance . in that type of accident you have like 1/3 of a full second as you try and stabilize your handlebars to no effect. however, if you are going slower the result is the wobble lasts longer and you can sometimes control the direction of the fall, or even turn a 'fall' into a 'slide out' which i have done many times. this means you fall down on your side but in a relatively controlled manner which results in scrapes and scratches and maybe a bruise but nothing broken and no major hard impact as if you are thrown onto the ground.
also in relatively common 'dooring' situations where are a vehicle door opens directly in front of your path, you have just a bit more time to swerve away from the window of the door infront of you, and fall away from the door as opposed to falling through it with your entire body. more importantly at slower speeds, you have a better chance of being able to stop short by slamming your brakes without an accident.
furthermore, there is the obvious reality that hittting an object , any object, at higher speed results in more force upon impact.
finally, the most overlooked reality is that going at a slower speed allows you to avoid FAR MORE accidents and allows others to avoid getting into accidents with you, particularly pedestrians who may otherwise not see you because they are not paying attention at all, or because you aren't paying attention to them.
if there is ONE and only ONE rule for cycling other than 'pay attention at all times' it is , RIDE SLOWLY. it is NOT 'wear a helmet'. no. ride slowly.
the best sped for a bicycle is under 14 miles an hour. at 12 miles an hour, you are basically just strolling around speed on a bike. In my experience most bicycle accidents occur between cyclists and pedestrians running into the street , or between cyclists and vehicle Doors, or between cyclists and potholes/uneven streets or hidden obstacles, slippery things on the street. for all of these most common causes of falls, speed greatly affects the outcome of both the likelihood of the accident occurring, and the results of the accident.
