Halo 15 to 12mm conversion
Some 12mm thru axle forks are only compatible with hubs which have end cones with a maximum outer diameter of 19mm. Several thru axle hubs have end cone outer diameters larger than 19mm (typically 21mm) and will not fit into the recessed area under the hub location lip.
To check the compatibility of your 12mm axle fork with any thru axle hub, measure distance ‘A’ in the diagram.
If ‘A’ is less than 4.5mm you can only use a hub that has a maximum outer diameter end cone size of 19mm. If ‘A’ is 4.5mm the fork should accept a hub using 21mm end cones.
If in doubt please consult your local dealer.