Shimano Nexus and Tiagra
On Metal you will find 2 groupsets: Shimano Nexus and Shimano Tiagra. Shimano Nexus are hub gears, ideal for commuting year-round, and requires low maintenance. Shimano Tiagra are however derailleur gears, which are more sports-specific. This means you have 10 gears, which are both precise and lightweight.