Carbon fiber is a
relatively new material and unique because it's not
a metal. It's a fabric that's impregnated with a
glue called resin that allows shaping and joining
of the material. Carbon frames are extremely light,
stiff and durable. Its greatest advantage is that
carbon can be manipulated essentially in endless
ways, which means it can be fine-tuned to provide
just about any ride quality desired. It's also impervious
to corrosion and can be built into beautiful shapes
producing Ferrari-like looks.
Like titanium, because
construction is somewhat complicated and because
carbon fabric and resins are costly, carbon frames
are on the high end of the cost spectrum. Carbon
is a popular material for forks due to its natural
ability to absorb shock while offering fine handling.
Regardless of what
bike you choose it won't be much fun riding it if
the gearing isn't appropriate for your fitness level
and where and how you pedal. Fortunately, all component
groups offer a variety of different gearing options.
And we can also modify things if needed to suit your
needs. Here's what's involved:
There
are sprockets on the front and back of the bike.
The front sprockets are called "chainrings" and
they're located on the crankset which is the part
that attaches the pedals. A double crankset has
two chainrings and the triple crankset has three
chainrings. The triple crankset includes a small
inner chainring which is the granny gear for easier
hill-climbing.
The sprockets on
the rear of the bike are called "cogs," or,
if you're referring to the entire cluster of gears,
it's called a "cassette" or "freewheel." The
cassette is attached to the rear wheel to drive it
as you pedal. Depending on the components on the
bike, there will be from 8 to 10 cogs on the rear
cassette.
To figure out how
many total gears are on a bike, simply multiply the
number of chainrings by the number of cassette cogs.
For example on a model with a triple crankset and
a 10-cog cassette, you have 30 gears -- quite an
upgrade from the 10-speeds so popular years ago.
How many gears you’ll
want depends on how and where you ride. If you're
reasonably fit and bike in flat to rolling terrain,
you'll probably be fine with a double chainring and
8 to 10 rear cogs. If it's hilly and you're getting
into shape, consider a compact crankset or triple
chainring with its easier gears.
To figure out how
easy it is to pedal the gears, you have to know a
little more about the chainrings and cogs. They are
referred to by the number of teeth on them. So, you
might read in bike specifications about 39/53 chainrings
and 12-23 cassettes. This means that the small chainring
has 39 teeth and the large has 53 teeth and that
the cassette has a small cog with 12 teeth on it
and a large one with 23. To know the size of every
cog, you usually have to count each one (usually
cogs and chainrings are marked, but, the marks can
be hard to see).
Don't let the numbers
confuse you. The key thing to know is that for chainrings,
larger numbers mean it's harder to pedal and vice
versa. For cogs, it's the opposite: the larger the
number, the easier it is to pedal and vice versa.
By keeping these rules in mind, you can quickly see
that a 30/42/52 triple crankset and a 12-27 cassette
will offer much easier gearing than a 39/53 double
with a 12-23 cassette.
