Replacement Blade Holder Bearing Collar HI2521054 for Hirobo Helicopters 9x11x5  [HI2521054]

Replacement collar for Hirobo blade holders

This RC-scale bearing collar is made for Hirobo helicopter blade holder assemblies. The 9x11x5 mm sleeve functions as a locating and retention component around the bearing area, helping to secure the blade hub while allowing the bearing to rotate freely.

Engineers and hobbyists fit this collar where accurate bearing seating affects blade tracking and pitch response. It is routinely chosen as an inexpensive replacement for collars that have worn and introduced excess play or uneven blade runout.

Installation notes: confirm the bearing is correctly seated in the blade holder prior to fitting the collar, clear mating surfaces of debris, and ease the collar into place without applying excessive force to avoid damaging bearing races. After installation, check for axial and radial play and verify blade tracking at low throttle before attempting flight.

Tuning role: a correctly installed collar maintains consistent blade alignment, supporting predictable pitch changes and improved cyclic smoothness which helps reduce ongoing trim adjustments during setup.