Ducati made the switch from Desmo valve actuation to spring valves on some of their models primarily to meet increasingly stringent emission regulations and to improve reliability and maintenance requirements. Here are the key reasons behind the transition:
Emission regulations: As emission standards became stricter around the world, Ducati needed to find ways to reduce emissions and improve fuel efficiency. The Desmo valve system, while effective in providing precise valve control and high-performance characteristics, can be more complex and demanding in terms of maintenance and fine-tuning. Switching to spring valves allowed Ducati to simplify the valve train and optimize it for better emission performance.
Cost and complexity: Desmo valve actuation, which uses a system of closing the valves mechanically with positive action, requires additional components and meticulous adjustments. This increases manufacturing complexity and can result in higher production costs. By adopting spring valves, Ducati was able to streamline the manufacturing process and potentially reduce costs.
Reliability and maintenance: The Desmo system, while iconic and effective for performance, requires more frequent valve adjustments compared to conventional spring valve systems. Spring valves have simpler maintenance requirements, as they do not require the same level of frequent adjustments, allowing for longer service intervals and potentially reducing maintenance costs for owners.
It's worth noting that Ducati has not completely abandoned the Desmo valve system. They continue to use it in many of their high-performance and flagship models, as it offers precise valve control, improved high-RPM performance, and a unique characteristic that appeals to enthusiasts. The decision to use spring valves on certain models is a strategic choice to balance performance, emissions, reliability, and cost considerations.