Question: What do clipless pedals enable a cyclist to do?
About the article "Cycling", section "Equipment".

Candidate passages:
Clipless pedals (also clip-in or step-in) require a special cycling shoe with a cleat fitted to the sole, which locks into a mechanism in the pedal and thus holds the shoe firmly to the pedal.
Most clipless pedals lock onto the cleat when stepped on firmly and unlock when the heel is twisted outward, although in some cases the locking mechanism is built into the cleat instead of the pedal.
Clipless refers to the toe clip (cage) having been replaced by a locking mechanism and not to platform pedals which would normally not have toe clips.
The clipless pedal was invented by Charles Hanson in 1895.
It allowed the rider to twist the shoe to lock and unlock and had rotational float (the freedom to rotate the shoe slightly to prevent joint strain).
The M71 was a clipless pedal designed by Cino Cinelli and produced by his company in 1971.
It used a plastic shoe cleat which slid into grooves in the pedal and locked in place with a small lever located on the back side of the pedal body.
To release the shoe a rider had to reach down and operate the lever, similar to the way a racing cyclist had to reach down and loosen the toestrap.
The lever was placed on the outside edge of the pedal so that in the event of a fall the lever hitting the ground would release the foot.
The pedal was designed for racing, in particular track racing, and because of the need to reach them to unclip they have been referred to as "death cleats".
In 1984, the French company LOOK applied downhill snow skiing binding or cleat technology to pedals producing the first widely used clipless pedals.
Initially used by triathletes in order to facilitate faster "transitions", Bernard Hinault's victory in Tour de France in 1985 then helped secure the acceptance of quick-release clipless pedal systems by cyclists.
Those pedals, and compatible models by other manufacturers, remain in widespread use today.
The cleat is engaged by simply pushing down and forward on the pedal, or, with some designs, by twisting the cleat in sideways.
Then, instead of loosening a toestrap or pulling a lever, the cyclist releases a foot from the pedal by twisting the heel outward.
The next major development in clipless pedals was Shimano's SPD (Shimano Pedaling Dynamics) pedal system.
Whereas Look cleats are large and protrude from the sole of the shoe, SPD cleats are small and could be fitted in a recess in the sole, making it possible to walk (although comfort will vary, as the soles of different cycling shoes vary in their rigidity depending on design).
Cycling shoes have rigid soles to maximize power transfer and efficiency.
They may be specific to road or mountain biking, or usable for both.
Shoes designed for mountain biking typically have recessed cleats that do not protrude beyond the sole of the shoe, and have treads for walking on trails, as walking or carrying the bike is often required.
Road cycling shoes are typically lighter than their mountain bike counterparts, and feature a protruding cleat and less weather proofing.
The protruding cleat makes these shoes impractical for walking, as doing so can damage the cleat.
Mountain bike cleats can generally be mounted without difficulty to road shoes although sometimes an adapter is required.
Such attachment is not usually possible for road pedals, as the cleats are normally too large to be mounted on mountain shoes.
The smaller mountain bike cleats are attached to the sole of the shoe by two bolts; larger road-specific cleats are attached by three.
Various manufacturers have produced their own designs of clipless pedal systems over the years, most notably BeBop, Campagnolo, Coombe, Crank Brothers, LOOK, Shimano, Speedplay, and Time. 
Mike King, along with fellow racer Brian Lopes, is credited with starting the Mountain Bike racing SPD clipless pedals trend in BMX racing starting in the mid-1990s, moving away from the then standard platform and cage pedals for racing.
They both raced with them at the ABA Fall Nationals in Burbank, California on October 22, 1994.
There is controversy in BMX over the use of clipless pedals, including that rider can not maneuver their feet off and on the pedals in turns when the racer wants to set up for a pass, or stabilize his or her bicycle in a low-speed, tight turn.
This reduces the opportunity to pass riders in the turns, as was commonplace in the 1980s when cage and platform pedals were the norm.
Some say that clipless pedals reduce the excitement of BMX races, with the racers "following the leader" and only having the ability to pass on straights.
Despite the respect given by the BMX world to Mike King and Brian Lopes, clipless pedals were not used by the majority of pro or amateur racers until the end of the year 2000.
It was the late Mario Soto, a young and highly talented rookie pro who broke into the Senior pro ranks and started immediately doing very well despite his comparatively small size and being totally new to the senior pro ranks, that prompted the move.
He attributed part of his success to his use of clipless pedals.
Today clipless pedals are the norm in BMX racing.
Wade Bootes a highly respected Senior Pro was an early adopter of clipless pedals and helped with the move to them.
Another criticism of clipless pedals is that they lead to more injuries since the feet can not be readily be freed from the pedals despite their quick release feature.
The racer is prevented from either stabilizing his bike by placing one foot on the ground to prevent a crash or brace himself quickly if a crash is inevitable, leading to more frequent and serious crashes involving leg and foot injury.
On August 20, 2007 professional BMX racer Bubba Harris completely dislocated ankle at the talus bone in Beijing, China on the official Olympic BMX racing track during the first run of his Time Trial in the "rhythm section", a series of closely but evenly spaced jumps that you use gravity and "body English" to navigate and maintain speed.
He was launched sideways by his momentum into the air, coming down on the back side of a jump with his foot still clipped into an SPD pedal.
Doctors almost amputated his foot.
With platform pedals his feet would had not been tied to the bicycle which acted like an anchor.
As of this time he is still recovering.
He expects to race the NBL Christmas Classic BMX race at the end of December 2007.
He was able to fulfill that expectation, but he did not make the mains.
Mishaps like this, though usually much less catastrophic, have ignited debate in the BMX racing community.
This is particularly true among "Old School" veterans of the 1970s and 1980s who raced with caged and platform pedals.
Generally the only danger with pedals of these types was that if the rider slipped a pedal, the teeth of the pedal could gouge his shin, thigh or ankle, unless the rider has protective padding.
In a January 7, 2009 interview with Gary Haselhorst on the BMX discussion site "BMX Action Online" Mike King said he went to clipless pedals because, "My motivation to use SPD pedals/shoes had to do with the ABA introducing a pro time trial in 1995.
Then it helped me when I was racing mountain bikes.
However, I think the clip debate is overrated.
I don’t think kids under 10 years old should be racing in them and I believe this has affected how tracks are designed today.
They are too many cookie cutter type tracks in this country and this has slowed the progression of the sport. 
Shimano Pedaling Dynamics, also known as SPD system is a design of clipless bicycle pedals.
The SPD pedal was released by Shimano in 1990.
While not the first, its innovation was its small cleat which fitted in a recess in the sole of a shoe designed for SPD use.
The shoe could be also used for walking whereas previous systems (other than the Cyclebinding system) had a large protruding cleat.
Clipless pedals use a system of cleat retention which is quite similar to that of a downhill ski binding.
Generally, clipless pedals are seen to be safer than the older style of pedal/shoe integration using toeclips, toestraps and shoeplates due to ease of disengagement.
There is a small allen key adjustment for the strength of heel twist to release, so beginners can have it 'soft' and easy to get out, and then tighten it up as they progress. 
Reflectors and reflective tape provide additional visibility (especially when applied to moving parts of the bicycle) and are mandatory in many jurisdictions.
Pedal reflectors in particular are very visible to following traffic as they move up and down; unfortunately they are not compatible with most clipless pedal systems, although adaptors are available for some, mainly older SPD models, and a few single-sided designs are available with built-in reflectors.
In the UK, where front and rear pedal reflectors are compulsory after dark, most cyclists with clipless pedals are therefore riding illegally.
The law is rarely if ever enforced, but could potentially be used in court to reduce financial compensation if the cyclist were to be hit by another vehicle.
The CTC have suggested that the requirement should be waived if the cyclist fits an additional rear reflector or lighting, but this was not changed in the last revision of the UK vehicle lighting laws (which permitted flashing LEDs).
Riders of recumbent bicycles have pointed out that the pedal reflector requirement is nonsensical for them, since the reflectors point straight up and down in use, and are invisible from other vehicles.
As of 2008, California law allows white or yellow shoe reflectors (front and back), or reflective ankle bands, in lieu of pedal reflectors. 
TIME Sport International is a French manufacturer of bicycles and cycling equipment, including bicycle frames, cycling shoes, clipless bicycle pedals, cranksets, and gloves.