Will a doorway pull-up bar damage my door frame?

It depends on the design and your trim. Across the doorway-bar reviewers and r/bodyweightfitness threads we read, the leverage-style bars (which hook over the top of the trim) commonly leave compression marks or scuffs on the trim molding, especially under heavier users. Bars that mount inside the frame and use a wedging or screw-tightened mechanism tend to leave less visible damage, but most reviewers recommend padding the contact points with felt or foam regardless.