I've managed it with a Tiagra mech on XT chainset (ended up using a Jtek offset shim), so I reckon GRX should stretch.
@Bearlegged 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.
I've managed it with a Tiagra mech on XT chainset (ended up using a Jtek offset shim), so I reckon GRX should stretch.