|
Design
The most popular frame design is known as the diamond or
double- triangle. This design has changed very little since the advent of
the saftey bicycle in the 1880s. Paolo explained, "It's proven to be
a great use of materials, great for bracing angles, great for strength;
it lends itself to being beat up pretty hard and still being ridable."
The strength of the design comes from the triangle shapes that make up the
diamond design. As Paolo explained, "Structurally, it's quite impressive.
If you look at engineers playing with structures, they tend to come back
to triangles and since the bike is basically three triangles, it works out
to be a pretty strong structure."
While the diamond design is the core of most bicycles built
today, some frame builders are experimenting with new variations on this
classic design. For example, some carbon-fiber frames are being made with
oval tubing, making the bicycle more aerodynamic. New full-suspension bikes
have altered the diamond design to allow for a large shock to be mounted
on the seat stem. However, most changes to the design are more subtle and
have to do with maximizing performance for different types of terrain or
uses.
|
|
IMAGE PROVIDED BY CANNONDALE BICYCLES
The Search For Suspension
Almost since the invention of the bicycle, designers have been trying
to come up with ways to soften the ride. In the 1880s, roads were unpaved
and tires were made of wood or metal. Although the pneumatic tire helped,
inventors were lured by the possibility of adding coil springs, lever arms,
swing- mounted rear triangles, bumpers, and other cushioning features to
the bike. In the 1930s, designers began to take ideas from motorcycles,
like the spring-coil front fork, and adding them to deluxe bikes.
Recently, with the soaring interest in mountain bikes, designers have
once again been exploring suspension with a vengeance. The rocky terrain
covered by mountain bikes makes suspension desirable once again. However,
suspension systems often bring added weight and odd steering and pedaling
characteristics. The advent of new ultralight materials, combined with refined
designs, have made suspension forks almost ubiquitous on the modern mountain
bike. Even the holy grail of "dual-suspension" has been attempted,
with the goal of suspending the rear wheel without altering the action of
pedaling. Many good designs have appeared, ranging from the venerable pivoting
rear triangle to a design where the riders sits on a carbon- fiber beam
levered out from the head tube. Though the added weight of these bikes is
still a problem, they have earned a growing following for their comfort
and handling.
|
|
