Want to build additional wagons? These wheelsets will get you up and running.
Four fully assembled wheelsets for your train mocs. Enough to outfit one or two wagons. These wheel sets come fully assembled, with ball bearings in LEGO® technic bricks, custom BrickTrack axles, washers to prevent wheels from rubbing the bricks, and BrickTracks train wheels.
Why use bearings? Because ball bearings provide excellent free rolling operation. Better than stock LEGO wheelsets. Less resistance means the wagons are easier to pull. And the easier a wagon is to pull the less strain on locomotives, and the more wagons you can pull.