The pros of a carbon frame: the lightest material for bicycle frames, no signs of metal fatigue, effective shock absorption and a more comfortable ride, usually with an extended manufacturer's warranty.
Disadvantages of a carbon frame: frame surface more susceptible to scratches and structural damage, usually less adaptable to racks, support rack, etc. for accessories
Aluminium frame pros: more robust and more forgiving to direct scratches and impacts, usually more versatile in terms of accessories.
Disadvantages of aluminium frame: heavier than carbon frame, possible signs of metal fatigue
TREK believes in carbon, which is why many of its bicycle components are made from carbon and why all carbon bicycle frames come with an unconditional lifetime warranty against industrial defects. As part of its loyalty programme, TREK will replace carbon rims damaged on stones or asphalt potholes and will support you with a substantial discount on a new frame if it is damaged in an accident.