I have a Sun EZ-1 Super Cruzer recumbent. It is the low end bike. It is beginning to be harder to pedal. Got at least 5,000 miles on it and never bearings have never been repacked or replaced. Wondering if it time. Also where can I get parts? Normally Sun only works through dealers.
Bearings need repacking and ball replacement when the wheel isn't running smoothly, or has crunchiness when rolling.
So it could be time to redo the bearings. Depending on what system the wheels use, it could be as little as a $5 packet of bearings and 5c worth of grease.
Sealed bearings are even easier - if they feel bad/rattly/noisy, they need replacing.
Specific to your bike, there's probably dirt and wear all over, so fixing one thing might not restore it to original performance. Consider giving the entire transmission a clean, check the chain for wear, check the tyre's air pressure and that there is no brake rub.