How do I prevent hand numbness on long rides with flat bars?

Install ergonomic grips with palm support (Ergon GP1 or similar), add bar ends for an alternate hand position, wear padded cycling gloves, and ensure your saddle is properly adjusted — a nose-down saddle shifts weight onto your hands. Taking regular hand-stretch breaks every 30 minutes also helps. If numbness persists on rides over 90 minutes, a drop-bar bike may be a better fit.