Cyclocross for a start.
Sram force 1 appears to have took a huge chunk of th CX market, ultegra di2 1x or 2x should take some of that back.
@Acliff started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Cyclocross for a start.