Park Tool DAG-3 Derailleur Hanger Alignment Gauge

Park Tool DAG-3 Derailleur Hanger Alignment Gauge Many gear shifting issues can be solved by ensuring that the derailleur hanger is perfectly true; this is where the Park Tool DAG-3 Derailleur Hanger Alignment Gauge comes in. It is used to check the hanger for alignment and then can be used to straighten it so that that derailleur sits in exactly the right place. It can be used with wheels from 16-29” and can even be used on bikes that have a rack or mudguard fitted. As it has been engineered to Park Tool’s exacting standards; it is both long-lasting and highly accurate.