Most early cars used a rear axle that was one unit, solidly linking both rear wheels, the differential and brake assemblies. Sports car competition showed that if the wheel assemblies can be made lighter, including brakes, hubs and axle parts, the car will ride and handle better. As a result, manufacturers have unlinked the wheel assemblies using jointed axles so the wheels can respond to bumps separately, thus giving a better ride and also more grip to the road.