All Mountain Bike Parts Descriptions
Sets - The Cassette. The thing with all the
gears on it.
These clusters of gears, are chosen for
their intended use. Small cogs, like an 11 tooth,
are for higher speeds, and big cogs, like a 34 tooth
will be slower but would have more torque for climbing.
Cog sets are available in singles, 5 speed, 6-7-8-9
and now ten speed "clusters". There are
two different types, Shimano or Campy. Both use a
splined center that slides over a Free Hub Body, and
both use a large ring nut to hold them onto the hub.
The difference is the spline will only fit it's own
Some of the teeth on the cogs have "pick up ramps" cut into the sides of them to help lift the chain
into a lower gear. Others have release cuts to make
it easier to drop the chain back down into a higher
Bike Parts Diagram