Hirobo HI2500114 3 x 9 x 4 mm Bearing Pair (2 pcs)  [HI2500114]

Shielded bearings for tight RC assemblies

This set provides replacement ball bearings intended for small rotating shafts and compact drivetrain spots in Hirobo helicopter assemblies and similar RC components. The kit contains 2 pieces sized 3 x 9 x 4 mm, suitable where limited space still requires reliable axial and radial support.

Common applications include support for motor pinions, small gear stages, and secondary shafts where controlling endplay and smooth rotation reduces noise and improves control feel. The item reference 93ZZ indicates a shielded style documented in the original listing, useful where some protection against contaminants is desired.

Fitting advice: check shafts and bore surfaces for wear, verify the 3 x 9 x 4 mm dimensions before installation, drive the bearing in squarely by applying force to the outer race only to protect the rolling elements, and apply a small amount of lubricant if recommended for the specific RC application.

Care recommendations: replace bearings as matched pairs to maintain symmetry, monitor for excess play after fitting, and include bearing condition in routine checks when troubleshooting vibration or unusual sounds in rotors or compact gear trains.