Most sensible cyclists know that mountain biking safety is something that has to be taken seriously; you need to be alert, even when you're out for a day's relaxation.
But life has a way of dishing up the occasional unexpected danger - particularly when animals are involved.
While there have been some nasty incidents involving wildlife, most end well for all those involved.
Here are a few lighter moments to enjoy.
50 kph Ostrich Chases Riders in Pre-race Warmup
The Cape Cycle Tour is one of South Africa's premier cycling event and one of the biggest such races in the world. This particular year it attracted 35000 entrants willing to tackle the 109 km course.
Some visitors got a little more excitement than they bargained for when they decided to do a small (only 130 km) warmup ride to the Cape of Good Hope nature reserve a few days before the main event.
Among other species, the Reserve is home to antelope, zebra - and ostriches!
The one in this video is a male in full breeding plumage. Males usually weigh more than 100 kg (220 lbs), can go up to 150+kg (about 340 lbs) and stand anything up to 2.8 meters (9 feet) tall!
"I thought I gonna fall of my bike from laughter," said one cyclist.
"The ostrich didn't have any problem to keep up at 50km/h and apparently they do 70km/h with no sweat."
Mountain Biker Taken Out By Antelope
The next one was also in South Africa, this time on an inland bush track near Albert Falls, in the KwaZulu-Natal Province, on South Africa's east coast.
The rider was one of the country's top young mountain bikers, Evan van der Spuy, of Team Jeep South Africa.
He was hit by a Red Hartebees, an antelope that can weigh up to 150 kg (330 lbs) and stand 1.3 meters (a little over 4 ft) at the shoulder.
The footage came from his team mate, Travis Walker, who was following behind witha GoPro camera.
Evan ended up in a neck brace, but has recovered and is back on his bike, still competing - and keeping and keeping a wary eye out for antelope.....
...and Finally, a Bit of a Tall Story!
This one comes from the Groenkloof Nature Reserve near Pretoria, one of South Africa's major cities.
The cyclists thought the giraffe looked " very tame" and started taking photographs - forgetting about the word "wild" in the phrase "wild animal".
When you consider that an adult male giraffe will be from 4.3 to 5.7 meters tall (14-19 ft) and weigh nearly 1200 kg (about 2650 lb) this might have been a bit careless.
The guy behind the camera started by offering some sarcastic comments along the lines of "Are you scared of a giraffe?" and "Now you're on your third lap".
But the (very expensive) bike ended up trampled underfoot; both cyclists had to take some rapid evasive action!
...and the Serious Side: Mountain Bike Protective Gear
While these film clips are good for a giggle, on a more serious note, is your protective gear up to scratch?
All bikers know that it's not whether you're going to crash - it's when.
Bikes are getting better, trails (particularly those that are specially constructed to test riders) are getting tougher, and everyone from beginner to expert seems to be pushing themselves harder as standards get higher and higher.
When soft moving objects hit hard immovable objects such as rocks, roots, trees and ditches it's the bikers' body that comes off second best unless it is properly protected.
These days there is gear designed to protect every part of your body, so it makes good sense to ensure you can get up from a fall with nothing hurt but your pride.
Mountain Bike Helmets
The most important piece of protective gear is your helmet.
There are two basic types - half shell or full face. The one you choose should be determined by the type of riding you do. If you're the over-achiever type following multiple disciplines, you will probably need more than one helmet.
Make sure it fits you properly; if it's too small it might leave part of your head unprotected when you hit the ground, while if it is too big you will find yourself with an irritating case of helmet wobble.
You can see a full range of helmets on Amazon here, or take a look at more specific categories below.
Cross-country helmets will normally be half-shell, light and with lots of ventilation to keep your head as cool as possible.
While light, it will probably be a little heavier than an equivalent road racing helmet.
The trail helmet will look similar to its cross-country cousin, but there will be more coverage of the head, particularly at the back and the sides (to protect your temples).
Still quite lightweight, still with good ventilation and airflow.
The headgear for those involved in dirt jumps is much more robust. The exterior is a hard shell, and there is normally less attention paid to ventilation. The liner inside is also harder, and is designed to offer more protection for the harder falls jumpers are likely to suffer.
This is for riders who embrace gravity and work with it - downhill racers, enduro riders and free trail riders.
The better helmets will have an EPP interior lining (see below).
Ventilation is much less important - protection comes first (but it does mean you won't want to wear this helmet for too long!)
Check Lining After a Crash!
Remember to check the inside lining of the helmet. Many will be made of polystyrene, which could deform if you have a big crash.
If that happens and you really ding your helmet - follow the manufacturer's recommendations and replace the helmet.
Higher-priced helmets, however, probably have an interior liner made of Expanded Polypropylene (EPP), which is elastic. If it is compressed in a hard fall it will return to its original shape, which means you can keep using it through a number of falls - depending on the severity, of course.
The bits of the body that stick out are normally the ones that get hurt, so having protected your head, you need also to think of arms and legs.
There is a wide variety of mountain bike protective gear - think elbow guards or elbow/forearm combos, knee and shin guards, and shoes.
Depending on what kind of event you tackle, you might need to look at padded shorts, armored jackets and even chest, back and spine protection.
If you need to update or expand your armor options, this link will take you to the mountain bike body armor page at Amazon.
Generally speaking these products are tough, yet flexible and soft and won't interfere with your freedom of movement.
And when the inevitable happens, they will go a long way towards keeping you free to continue moving!