The Abbey Bike Tools preHAG will let you quickly check your derailleur hanger alignment pre-race. Press it down on the largest cog in your cassette, with no need to remove the derailleur, let it hang, and see if it's parallel to the cassette.
A simple tool that is meant to gauge derailleur hanger alignment without having to remove the rear wheel
Presses onto the largest cog on the bike to quickly provide a reference to judge if further attention is needed
