Bike trials is a form of off-road cycling derived from motorcycle trials where one slowly negotiates man-made and natural obstacles. It originated in Spain and is said to have been invented by Ot Pi's father (A world champion motorcross trials rider) who wanted his son to learn and practice motorcycle trials on an ordinary push bike instead of a motorbike as it is hard for small children to control motorcross trials bikes.
At the most basic level, trials riding can be summed up as bicycle handling skills. It evolved from motorcycle trial riding (riding up, over obstacles, man-made or natural) into an off-season bicycle pastime. It now has a strong, though small following and can be seen worldwide. Skills taken from trials riding can be used practically on any bicycle for balance, standing still while still on the pedals, braking, and many other uses. Trial bike characteristics include, but are not limited to: powerful brakes, wide handlebars, light parts, low gearing and a heavy emphasis on frame geometry.
It is totally different from individual time trial races, which are an element of road bicycle racing.
Rulings
The general principle in a bike trials competition is to ride a number of pre-marked sections (usually 2 laps of 10 sections or 3 laps of 7 sections), the winner being the rider with the least points at the end of the competition.
The maximum number of points that can be obtained in each section is 5, the lowest (and best) score is 0 points. The most common way to gain a point is by putting your foot down within a section, for this reason points are sometimes known as "dabs". Certain rules enforce the number of points gained within a section, for example, putting both feet down will result in 5 points. Exceeding the time limit for the course will either result in 5 points (BIU rules) or an additional point for every 15 seconds over the limit (UCI rules).
Types of bike trials
Currently there are two regulated types of competition ruling, enforced by the UCI and BikeTrial International Union.
UCI
Within UCI ruling, if any part of the bike except the tires rest on an object in the course, a dab will be given. The UCI rules were changed to this format after too many competitions ended in a draw and riders were forced to ride an extra section. Under UCI rules also allows riders to compete in both stock and mod categories.
Other UCI Rules Riders in the 26" class must also have 6 working gears. When riding a section both tires must never cross the tape even if they are in the air. Each hand must remain on the handlebars at all times at any cost.
BIU
The rules are unlike UCI scoring and parts of the bike can rest on a section object without resulting in a 'dab'. The sections at BIU events are typically harder and more technical to make up for the use of the bash plate and pedals. The BIU is also more based around the modified category as the sections are set the hardest for the Elite 20" Modified class. In order to compete in the Elite class you have to qualify as one of the top 20 riders in the world. The level of riding for the elite 20" class is regarded as the F1 of bicycle trials since the section difficulty is set at the highest technical level.
Types of bikes
Trials bikes are no longer standard mountain bikes, but over the years have become very specialized. The two types of biketrials have created two different types of bikes. The bikes can be put into two classes, classified by the wheel sizes of 20" and 26", mod and stock respectively.
20", "Modified"
The 20" variety of trials bike (known as "Modified" or "Mod" bikes) are more specifically designed for bike trials, consisting of only 1 gear, a bashplate for resting on, and a large rear tire similar to a trials motorcycle rear tire. The term "Mod" comes from the fact that the frames were originally modified BMX frames, now used for trials. Ot Pi's father created the first trials bike, he took a normal BMX frame and modified the parts on the bike to make it more suitable for trials.
26", "Stock"
The 26" variety of trials bike (known as "Stock" bikes) were originally derived from normal mountain bikes although now the only similarities are the wheel size. These bikes consist of a minimum of 6 gears and typically have a longer wheelbase for the competition specific frames. This type of bike has become more and more popular as riders can use traditional mountain bikes found at your local cycling shop.
"New School" 26" bikes have higher bottom bracket to increase bashring clearance. In addition the length from the rear wheel to the front wheel is lengthened by a slacker head angle to make "taps" easier for the rider. This geometry eases balancing and jumping ("Gapping") from and on the back wheel. Modern 26" style bikes also have short chainstays to make riding more stable on the rear wheel. They are often referred to as bikes with "new school" geometry since they resemble a modified or 20" trials bike and not a mountain bike where the stock category was once based around.
"Old school" 26" bikes tend to have a shorter wheelbase, steeper head angles, and longer chainstays. They are typically used for street style trials or smaller riders and the bikes are not as specialized. These bikes tend to appear more along the lines of a mountain bike than the "new school" 26" bikes.
Due to the recent surge of street riding, particularly in the UK, there are now 24" trials bikes being released. These are generally shorter for increased flickability and are used almost exclusively for street riding in a more BMX like, flowing style. These bikes are illegal to enter in most competitions due to the wheel size but are also not very suited for natural riding in comparison to a "mod" bike or a modern "stock" bike.
Via: WIkipedia
All text is available under the terms of the GNU Free Documentation License.
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