Speed is where it's at, and as avid cyclists if we all had an unlimited
bank account or a tooth fairy life would be much easier. This is
especially true when you look at the cost of bottom brackets fabricated
with the newest in ceramic bearings.
Does it make sense to spend four times the money for ceramic bearings
or is it just a cool thing to talk about? This is the typical issue
when debating the choice of which of the many FSA bottom brackets
is right for you.
So, are ceramic bearings worth paying for... maybe ..
- they are 60% lighter than steel so the centrifugal forces
are reduced with less rotating mass and offer the bicycle rider
faster speeds and more responsive acceleration and deceleration
- ceramic balls will not "cold weld" to the bearing
rings, so friction is reduced and wear particles don't build
up in the lubricant, giving you longer life.
- silicon nitride balls have a 50% higher modulus of elasticity.
In other words they are not nearly as likely to get out of shape
than their steel cousins. This offers reduced vibration.
- Ceramic has 35% less thermal expansion, so FSA is able to
build their ceramic bearings, inner and outer rings, the raceway
and seals to tighter tolerances for smoother riding.
- Rust is not a concern. Ceramic is chemically inert, thus less
maintenance and less lubrication necessary.
FSA
suggests that their raw ceramic pellets are made via a secret
process! It was developed by a small Swedish firm that was spun
off from the international bearing manufacture SKF, the original
inventors of ceramic bearing technology.
Although ceramic bearings can be made from silicon nitride or
zirconium oxide, FSA ONLY uses silicon nitride for its reduced
weight/strength characteristics. It is formed under extremely
high pressure, lapped to a precise spherical shape with fine diamond
grit and then sintered into hard balls to create the perfect FSA
bottom bracket bearing.
They use ceramic only for the balls and steel for the raceways,
retainers and rings to create what is known in the industry as
a "hybrid" bearing.
So should you spend the money? Well FSA has been testing these
bearings for 2 years now and their data would suggest 5-10 times
longer life expectancy. Thus if you pay 5 times the price of a
regular steel version then you pretty well come out even and all
the riding benifits of faster speeds, reduced vibration and less
maintenance are all bonuses.
Maybe it is at this point I should tell you that tests by the
Danish magazine Cykel-Motion and SKF suggested up to a 50% reduction
in rolling resitance with the use of ceramic bearings
Of course if you're a casual rider then you'll never reach the
intended mileage of your bearing and bottom bracket so you're
probably wasting your money, but see if on the internet you can
find a real bargain and make the math work for you, happy riding.
Further Information:
FSA Bike Parts
Index of FSA Bicycle Part Articles
