Chain and transmission
The basic principle of a pedal-driven chain connecting with teeth on the rear wheel has not changed for decades, except for the usual weight-saving use of newer materials.
It might seem amateurish but chains do still snap in the professional world so mechanics clean and lubricate this most important of components on a daily basis.
The gear ratios themselves are very different to the leisure, commuting or mountain bike.
The double chainring at the front means twice as many gears for riders who need every bit of mechanical help they can get.
