The plates and rods are responsible for transmitting the strength of the cyclist to the chain and this, in turn, to the wheel of the bicycle.
They consist of one or several plates attached to the cranks at the end of which are the pedals. There is one connecting rod for the right leg and one for the left and they are mounted 180 degrees to each other, joined by the bottom bracket.
In triathlon , it is recommended to use smaller cranks every time, between 165 and 172mm. These numbers vary depending on the height of the athlete. For example, someone who measures between 1.7 and 1.78 m is recommended a 170mm rod. It will also have to take into account the type of dish to be used and the teeth it has. Following the same example, a person using 170mm cranks would do well with a 50-tooth plate.
It can be said that the bottom bracket is the heart of the bike, since it is one of the most important elements of the bike but there is not much talk about the bottom bracket since it is normally not in sight. Almost all the bottom brackets are sealed and with the joints sealed, they are assembled under pressure and can not be disassembled, but they can be greased to improve their performance.
These axles do not give many options to have a good maintenance or repair and so if it breaks down as normal is that you have to change the bottom bracket completely.
Popular Triathlon Chainsets & Bottom Brackets brands: