How to adjust a bike chain for optimal performance and longevity?

To adjust a bike chain for optimal performance and longevity, first, ensure the chain is clean and lubricated. Then, check the tension by lifting the chain at the midpoint of the bike. Adjust the tension by loosening the rear wheel and moving it back slightly if needed. Make sure the chain is properly aligned with the gears and sprockets. Finally, test the bike to ensure smooth shifting and pedaling. Regular maintenance and cleaning will help extend the life of the chain.