Keith Bontrager (/bɒnˈtreɪɡər/; born December 18, 1954) is a motorcycle racer[1] who became a pioneer in the development of the modern mountain bike.
[citation needed] 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developed frames out of (oversized) aluminium, titanium, or carbon-fibre, Bontrager believed steel was not outdated but that its design and production could be improved.
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.
Bontrager's versions of the Switchblade with bonded and riveted dropouts and brake bosses led to a fork with no welding or brazing, thus retaining the strength gained by tempering the tubing.
At this same time, Bontrager stopped using two-piece seat stays on mountain frames in favor of a single tapered tube.
He has also competed in the Three Peaks Cyclo-Cross event in England, as well as stage races such as the Trans-Sylvania Mountain Bike Epic in State College, PA. Bontrager majored in physics at UCSC.