Why compact crankset?
|By Per Bausager
It is FSA that invented the compact crank set. It is a invention that is just as simple as it is ingenious. The idea is in reality an answer to the same need the triple crank set covered, specifically to achieve a gearing so fitness cyclists can tackle the most difficult climbs without "breaking their legs".
The concept behind the compact crank set is that one reduces the number of teeth on a chain ring, for example one would instead of the traditional 39/53 combination have a 34/50. Henceforth with the use of a 11/25 cassette be able to achieve a gearing only possible with a triple. And the biggest gear 50x11 will bring the bicycle longer forward per pedal revolution than the alternative 53x12, it would be the equivalent of a 53x11.7. The smallest gear of this combination 34x25 would be the equivalent of a 39x29.
There are additional advantages with this solution:
1. Much lower weight than a triple solution which would require a longer crank axle, longer gear arm and 3 bigger chain rings.
2. The solution can be realized on the present bicycle without having to change anything but the crank set.
3. A shorter axle (smaller Q-factor, which means better power transfer, better aerodynamics and lower weight.
Campagnolo now offers a compact crank set, as well as a special front deraileur in both the record and