Keith Bontrager
Encyclopedia
Keith Bontrager is a motorcycle
racer who became a pioneer in development of modern mountain bike
. Between 1980 and 1995 he was president of Bontrager Cycles. Bontrager continues to develop components for Trek
, which bought his company.
In 1969 he began racing motocross
, funding his racing through motorcycle
repair work. Between 1975 and 1981 he designed, built and tuned motocross and road racing
and drag racing motorcycles. Motorcycles he tuned won national road racing titles in production and 250 GP
classes.
and in 1979 built his first road bike
. With his motocross background he was attracted to mountain bike
cycling. In 1980 he built his first mountain bike frame
and founded Bontrager Cycles in Sunnyvale
, California
.
In 1984 he cut 700C (ISO 622) 40-hole Mavic
MA-2 tandem rims
to the circumference of a 26" rim, re-rolling them to create a 32-hole 26" rim.
Bontrager rims were the first lightweight yet strong mountain bike rims, albeit using a profile intended for road racing bicycles. Mavic provided MA-40 MTB rims for some time. Bontrager went on designing lightweight rims, manufactured by Weinmann USA. Several were introduced but never went into high production as the Weinmann plant suffered a fire.
The design of Bontrager frames was based on his studies at the University of California, Santa Cruz
and experience as a motocross mechanic. While other manufacturers developed frame
s out of (oversized) aluminium
, titanium
, or carbon-fibre, Bontrager believed steel
was not outdated but that its design and production could be improved. Joints could be strengthened by gusset
s to distribute loads and reduce the weakening of brazing
and welding
. He found areas in which joints could be made by bonding and rivet
ing, i.e. the frame
s made between 1989 and 1994 had cable stops milled out of Aluminum that were bonded and rivet
ed to the top tube
. Frames made at Bontrager's Santa Cruz
workshop had two-piece seat stays
made of larger diameter
tubing in the upper area which added torsional stiffness
around the brake-bosses, while the smaller tubes in the lower area reduced weight and vertical stiffness of the rear triangle
leading to better damping of hits.
Bontrager published articles on bicycle design and construction, ranging from the effects of TIG welding
on the tubes to the flaws in the accepted sizing methods of the day.
In 1987 he designed and patented the composite fork
crown. This used an aluminum fork crown that clamped the fork blades and the steerer instead of using welds or brazing. This design was used on the Rock Shox RS1 suspension fork, and Bontrager's own rigid fork, the Switchblade. Bontrager's belief in avoiding heat affection of the tubes led to versions of the Switchblade with bonded and rivet
ed dropouts
and brake bosses leading to a fork with no welding
or brazing
. This retained the strength gained by tempering
the tubing.
In 1992 Bontrager Cycles expanded from a one-man shop to a limited production facility. In 1993 they started to produce handlebar
stems. In 1995 Bontrager's business partner, Hans Heim, left to join Santa Cruz Cycles, and put his share of Bontrager Cycles up for sale. Trek acquired Bontrager Cycles and hired Bontrager as president.
Bontrager production split in two. The frameshop in Santa Cruz
continued to manufacture the high-end mountain bike frames (the Race and Race Lite models), the Road Lite (road race
), the cyclo-cross
frames, and later a BMX
frame. At this same time, Bontrager stopped using two-piece seat stays on mountain frames in favor of a single tapered tube. The Ti Lite, a titanium version of the mountain bike frame, was made by tubing manufacturer Sandvik
. At the same time, the Privateer, an entry-level frame, was designed using the same True Temper tubing as the Santa Cruz-made-frames but made at Trek's plant in Waterloo, Wisconsin
with small design changes.
Bontrager took on product development at Trek, designing handlebars
, handlebar stems
, bar end
s, seatpost
s, tires
, crankset
s and rims
and wheels
.
By the end of the 90s production techniques for aluminium frames allowed cheap mass-production. Hardtail steel frames went out of fashion. Production of Bontrager frames ceased in Santa Cruz and Wisconsin.
Bontrager continues to work with Trek to develop wheels and components for mountain, road and triathlon bikes. The components were used by the US Postal, Discovery Channel, Leopard Trek, Trek Livestrong, Science in Sport and Trek VW road cycling teams. Triathletes and Ironman champions have used the components and these include Chris Lieto, Normann Stadler and Julie Dibens - to name but a few.
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
racer who became a pioneer in development of modern mountain bike
Mountain bike
A mountain bike or mountain bicycle is a bicycle created for off-road cycling. This activity includes traversing of rocks and washouts, and steep declines,...
. Between 1980 and 1995 he was president of Bontrager Cycles. Bontrager continues to develop components for Trek
Trek Bicycle Corporation
Trek Bicycle Corporation is a major bicycle and cycling product manufacturer and distributor under brand names Trek, Gary Fisher, Bontrager, Klein and until recently, LeMond Racing Cycles...
, which bought his company.
Motorcycles
Bontrager started in 1965 by building lawnmower engine powered mini-bikes.In 1969 he began racing motocross
Motocross
Motocross is a form of motorcycle sport or all-terrain vehicle racing held on enclosed off road circuits. It evolved from trials, and was called scrambles, and later motocross, combining the French moto with cross-country...
, funding his racing through motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
repair work. Between 1975 and 1981 he designed, built and tuned motocross and road racing
Road racing
Road racing is a general term for most forms of motor racing held on paved, purpose-built race tracks , as opposed to oval tracks and off-road racing...
and drag racing motorcycles. Motorcycles he tuned won national road racing titles in production and 250 GP
Grand Prix motorcycle racing
Road Racing World Championship Grand Prix is the premier championship of motorcycle road racing currently divided into three distinct classes: 125cc, Moto2 and MotoGP. The 125cc class uses a two-stroke engine while Moto2 and MotoGP use four-stroke engines. In 2010 the 250cc two-stroke was replaced...
classes.
Bicycles
In 1978 Bontrager became attracted to cyclingCycling
Cycling, also called bicycling or biking, is the use of bicycles for transport, recreation, or for sport. Persons engaged in cycling are cyclists or bicyclists...
and in 1979 built his first road bike
Racing bicycle
A racing bicycle, also known as a road bike, is a bicycle designed for competitive road cycling, a sport governed by according to the rules of the Union Cycliste Internationale...
. With his motocross background he was attracted to mountain bike
Mountain bike
A mountain bike or mountain bicycle is a bicycle created for off-road cycling. This activity includes traversing of rocks and washouts, and steep declines,...
cycling. In 1980 he built his first mountain bike frame
Bicycle frame
A bicycle frame is the main component of a bicycle, on to which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles, a main triangle and a paired rear triangle...
and founded Bontrager Cycles in Sunnyvale
Sunnyvale, California
Sunnyvale is a city in Santa Clara County, California, United States. It is one of the major cities that make up the Silicon Valley located in the San Francisco Bay Area...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
.
In 1984 he cut 700C (ISO 622) 40-hole Mavic
Mavic
Mavic is a French bicycle parts manufacturer, its name an acronym for Manufacture d'Articles Vélocipédiques Idoux et Chanel, founded by Charles Idoux and Lucien Chanel. The company is noted as a manufacturer of bicycle wheels. Mavic is based in Annecy, France...
MA-2 tandem rims
Bicycle wheel
A bicycle wheel is a wheel, most commonly a wire wheel, designed for bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels....
to the circumference of a 26" rim, re-rolling them to create a 32-hole 26" rim.
Bontrager rims were the first lightweight yet strong mountain bike rims, albeit using a profile intended for road racing bicycles. Mavic provided MA-40 MTB rims for some time. Bontrager went on designing lightweight rims, manufactured by Weinmann USA. Several were introduced but never went into high production as the Weinmann plant suffered a fire.
The design of Bontrager frames was based on his studies at the University of California, Santa Cruz
University of California, Santa Cruz
The University of California, Santa Cruz, also known as UC Santa Cruz or UCSC, is a public, collegiate university; one of ten campuses in the University of California...
and experience as a motocross mechanic. While other manufacturers developed frame
Bicycle frame
A bicycle frame is the main component of a bicycle, on to which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles, a main triangle and a paired rear triangle...
s out of (oversized) aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
, titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
, or carbon-fibre, Bontrager believed steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
was not outdated but that its design and production could be improved. Joints could be strengthened by gusset
Gusset
In sewing, a gusset is a triangular or rhomboid piece of fabric inserted into a seam to add breadth or reduce stress from tight-fitting clothing...
s to distribute loads and reduce the weakening of brazing
Brazing
Brazing is a metal-joining process whereby a filler metal is heated above and distributed between two or more close-fitting parts by capillary action. The filler metal is brought slightly above its melting temperature while protected by a suitable atmosphere, usually a flux...
and welding
Welding
Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...
. He found areas in which joints could be made by bonding and rivet
Rivet
A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked A rivet...
ing, i.e. the frame
Bicycle frame
A bicycle frame is the main component of a bicycle, on to which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles, a main triangle and a paired rear triangle...
s made between 1989 and 1994 had cable stops milled out of Aluminum that were bonded and rivet
Rivet
A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked A rivet...
ed to the top tube
Bicycle frame
A bicycle frame is the main component of a bicycle, on to which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles, a main triangle and a paired rear triangle...
. Frames made at Bontrager's Santa Cruz
Santa Cruz, California
Santa Cruz is the county seat and largest city of Santa Cruz County, California in the US. As of the 2010 U.S. Census, Santa Cruz had a total population of 59,946...
workshop had two-piece seat stays
Bicycle frame
A bicycle frame is the main component of a bicycle, on to which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles, a main triangle and a paired rear triangle...
made of larger diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
tubing in the upper area which added torsional stiffness
Stiffness
Stiffness is the resistance of an elastic body to deformation by an applied force along a given degree of freedom when a set of loading points and boundary conditions are prescribed on the elastic body.-Calculations:...
around the brake-bosses, while the smaller tubes in the lower area reduced weight and vertical stiffness of the rear triangle
Triangle
A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted ....
leading to better damping of hits.
Bontrager published articles on bicycle design and construction, ranging from the effects of TIG welding
Gas tungsten arc welding
Gas tungsten arc welding , also known as tungsten inert gas welding, is an arc welding process that uses a nonconsumable tungsten electrode to produce the weld...
on the tubes to the flaws in the accepted sizing methods of the day.
In 1987 he designed and patented the composite fork
Bicycle fork
A bicycle fork is the portion of a bicycle that holds the front wheel and allows the rider to steer and balance the bicycle. A fork consists of two fork ends which hold the front wheel axle, two blades which join at a fork crown, and a steerer or steering tube to which the handlebars attach ...
crown. This used an aluminum fork crown that clamped the fork blades and the steerer instead of using welds or brazing. This design was used on the Rock Shox RS1 suspension fork, and Bontrager's own rigid fork, the Switchblade. Bontrager's belief in avoiding heat affection of the tubes led to versions of the Switchblade with bonded and rivet
Rivet
A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked A rivet...
ed dropouts
Dropout (bicycle part)
A bicycle dropout is a type of fork end that allows the rear wheel to be removed without first derailing the chain. The more inclusive term fork end refers to a slot in a frame or fork where the axle of the wheel is attached....
and brake bosses leading to a fork with no welding
Welding
Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...
or brazing
Brazing
Brazing is a metal-joining process whereby a filler metal is heated above and distributed between two or more close-fitting parts by capillary action. The filler metal is brought slightly above its melting temperature while protected by a suitable atmosphere, usually a flux...
. This retained the strength gained by tempering
Tempering
Tempering is a heat treatment technique for metals, alloys and glass. In steels, tempering is done to "toughen" the metal by transforming brittle martensite or bainite into a combination of ferrite and cementite or sometimes Tempered martensite...
the tubing.
In 1992 Bontrager Cycles expanded from a one-man shop to a limited production facility. In 1993 they started to produce handlebar
Bicycle handlebar
Bicycle handlebar or often bicycle handlebars refers to the steering mechanism for bicycles; the equivalent of a steering wheel. Besides steering, handlebars also often support a portion of the rider's weight, depending on their riding position, and provide a convenient mounting place for brake...
stems. In 1995 Bontrager's business partner, Hans Heim, left to join Santa Cruz Cycles, and put his share of Bontrager Cycles up for sale. Trek acquired Bontrager Cycles and hired Bontrager as president.
Bontrager production split in two. The frameshop in Santa Cruz
Santa Cruz, California
Santa Cruz is the county seat and largest city of Santa Cruz County, California in the US. As of the 2010 U.S. Census, Santa Cruz had a total population of 59,946...
continued to manufacture the high-end mountain bike frames (the Race and Race Lite models), the Road Lite (road race
Road bicycle racing
Road bicycle racing is a bicycle racing sport held on roads, using racing bicycles. The term "road racing" is usually applied to events where competing riders start simultaneously with the winner being the first to the line at the end of the course .Historically, the most...
), the cyclo-cross
Cyclo-cross
Cyclo-cross is a form of bicycle racing. Races typically take place in the autumn and winter , and consists of many laps of a short course featuring pavement, wooded trails, grass, steep hills and...
frames, and later a BMX
BMX
Bicycle motocross or BMX refers to the sport in which the main goal is extreme racing on bicycles in motocross style on tracks with inline start and expressive obstacles, and it is also the term that refers to the bicycle itself that is designed for dirt and motocross cycling.- History :BMX started...
frame. At this same time, Bontrager stopped using two-piece seat stays on mountain frames in favor of a single tapered tube. The Ti Lite, a titanium version of the mountain bike frame, was made by tubing manufacturer Sandvik
Sandvik
Sandvik is a Swedish company founded in 1862 by Göran Fredrik Göransson in Sandviken. It is a high-technology engineering group and a world-leader in tooling, stainless steel alloys and materials technology, mining and construction...
. At the same time, the Privateer, an entry-level frame, was designed using the same True Temper tubing as the Santa Cruz-made-frames but made at Trek's plant in Waterloo, Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
with small design changes.
Bontrager took on product development at Trek, designing handlebars
Bicycle handlebar
Bicycle handlebar or often bicycle handlebars refers to the steering mechanism for bicycles; the equivalent of a steering wheel. Besides steering, handlebars also often support a portion of the rider's weight, depending on their riding position, and provide a convenient mounting place for brake...
, handlebar stems
Stem (bicycle part)
The stem is the component on a bicycle that connects the handlebars to the steerer tube of the bicycle fork. Sometimes called a goose neck, a stem's design belongs to either a quill or threadless system, and each system is compatible with respective headset and fork designs:-Quill vs...
, bar end
Bar End
Bar End is an area of Winchester, Hampshire, England. It lies on the east bank of the River Itchen to the north of St. Catherine's Hill and is the location of a park and ride car park serving the city centre....
s, seatpost
Seatpost
A bicycle seatpost, seatpin, saddlepole, saddle pillar, or saddle pin is a tube that extends upwards from the bicycle frame to the saddle. The amount that it extends out of the frame can usually be adjusted, and there is usually a mark that indicates the minimum insertion...
s, tires
Bicycle tire
A bicycle tire is a tire that fits on the wheel of a bicycle, unicycle, tricycle, quadracycle, bicycle trailer, or trailer bike. They may also be used on wheelchairs and handcycles, especially for racing...
, crankset
Crankset
The crankset or chainset , is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain, which in turn drives the rear wheel...
s and rims
Rim (wheel)
The rim of a wheel is the outer circular design of the metal on which the inside edge of the tire is mounted on vehicles such as automobiles. For example, on a bicycle wheel the rim is a large hoop attached to the outer ends of the spokes of the wheel that holds the tire and tube.In the 1st...
and wheels
Bicycle wheel
A bicycle wheel is a wheel, most commonly a wire wheel, designed for bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels....
.
By the end of the 90s production techniques for aluminium frames allowed cheap mass-production. Hardtail steel frames went out of fashion. Production of Bontrager frames ceased in Santa Cruz and Wisconsin.
Bontrager continues to work with Trek to develop wheels and components for mountain, road and triathlon bikes. The components were used by the US Postal, Discovery Channel, Leopard Trek, Trek Livestrong, Science in Sport and Trek VW road cycling teams. Triathletes and Ironman champions have used the components and these include Chris Lieto, Normann Stadler and Julie Dibens - to name but a few.