Mountain Biking
Матвеева Ю. и Петрачкова
В., 9»А».
Downhill bikes and equipment
•
Modern race downhill bikes weigh between 16 to 19
kg (35 to 42 pounds), and usually feature fullsuspension and frame geometries that lean back
farther (slacker geometry) than other mountain
bikes. As of 2006, 203 mm (8-inch) is the 'norm' for
suspension travel however some commercially
available big mountain freeride bikes can have over
300 mm (12-inch). Large-diameter 203–5 mm (8inch) hydraulic disc brakes moderate speed.
Downhill bikes and freeride bikes are very similar
but there are some slight differences. Downhill race
bikes typically are much lower and have slacker
head angles than freeride bikes, so that the bike is
more stable at speed and in corners. Freeride bikes
have a steeper geometry and a higher bottom
bracket height, so that they are better for balance
and maneuverability, however freeride bikes
sometimes use single crown forks, which are
shorter in travel length and lighter than the dual
crown forks often used by downhill riders, dual
crown forks usually have around 200 mm (8-inch) of
travel, and single crown forks are usually around
180 mm (7 in) maximum.
•
Downhill gear features body armor and full-face
motocross-type helmets. Other protective gear such
as a neck brace can be added to reduce the risk (by
bringing the head to a controlled stop)[6] of neck
and spinal injury.
Governing bodies
•
The Union Cycliste Internationale
is governing body for downhill
mountain bike racing. Racers
qualify to compete in World Cup
races by earning UCI points,
which are gained by being a top
ten finisher in certain races,
usually national.
•
In the U.S., NORBA, as part of
USA Cycling, runs the National
Mountain Bike Series, and the
NCCA is the governing body for
collegiate cycling. In the UK,
British Cycling controls mountain
biking as well as road and BMX. In
Australia, MTBA controls all
disciplines of Mountain biking.
Downhill racing venues
•
•
United States
The Sea Otter Classic, held each April at Laguna
Seca near Monterey, California, is a major riding
event that opens the racing season (course map).
The 2006 U.S. National Championships were held
at the Infineon Raceway in Sonoma, California. In
2007 and 2008 the U.S. National Championships
were held in Mt. Snow, Vermont. In 2009 and 2010
the U.S. National Championships were held at (Sol
Vista Bike Park in Colorado.) Plattekill Mountain in
the Catskills, Mammoth Mountain, the Northstar at
Tahoe, Brian Head Resort, Attitash and Deer Valley
ski resorts, and Moab UT are also well known to
mountain bikers. In the southeastern United States,
Snowshoe Mountain is well known for its extensive
mountain bike park, camps, and even freeriding
areas during the summer.[8] Vail, Colorado was the
site of the 1994 Downhill World Championship. The
trail was renamed "'94 Downhill," and is still ridden
by many downhill bikers today. It was considered
one of Vail Mountain's hardest venues.
•
Aaron Gwin is currently the U.S's top ranked racer
on the World Cup Circuit. In 2010 he finished his
World Cup Campaign with a 4th place world ranking
and a 4th place at the UCI mountain bike world
championships. He races for the Yeti/Fox Racing
Shox World Cup Team along with teammate Jared
Graves.
History
•
The 1st downhill time-trial race took place in Fairfax, California on October
22, 1976 on a fireroad now referred to as Repack Road, due to the need to
repack the single rear hub brake after a descent. The bikes used were
based on beach cruisers that had a single rear brake that worked by
pedalling backwards. A mechanism came into operation causing a conical
metal (bronze?) brake shoe to be wound on a thread into a conical metal
hub. To prevent a metal to metal brake from snatching it was always filled
with grease. Heavy use of the brake during the descent would cause the
brake to over heat, melting the grease till it drained from the hub and
required repacking. Ten riders descended 1300 feet of Repack in about 5
minutes.[3] The first bikes used for descending were known as "klunkers" or
"paperboy bikes": coaster brake cruisers using balloon tires first imported to
America by Ignatz Schwinn.[4] By 1979, two organizers and competitors of
the Repack downhill, Charlie Kelly and Gary Fisher founded the company
which named the sport, MountainBikes.[5] As mountain biking grew
enormously during the 80s, downhill riders continued to use either rigid or
limited suspension travel (under 2 inches) bicycles, and purpose made
downhill bikes were not made until the 90s. Some of these innovations
included dual crown suspension forks and disc brakes, as well as very
elaborate frame suspension designs.