As an Ohlins Service Center we have serviced almost every brand under the sun: Penske, Jri, Elka, RaceTech, Showa, KYB, Hyperpro, Wilburs, along with OEM brands like Showa, KYB, Sachs and even Paioli. They all have common parts and issues. A standard Ducati fork could be similar internally to a Honda or Suzuki fork. Oil, shims and seals are what you will find on the inside. They all need to be serviced. I once had a BMW rider tell me that he wouldn't buy a aftermarket shock because they have to be serviced every 20k miles. I just shook my head! He had no idea what he was missing. He was probably burning up the cost difference in tire wear. Page down to see for yourself!
Over the years we have serviced thousands of forks and shocks. Experience shows us over and over that to keep your suspension working like new the suspension should be serviced at the proper interval.
Racing: For racing we recommend a full suspension service performed every season. Followed by oil changes every 3 to 4 races.
Track Day/Club racers: Keep it simple by starting out with a fresh suspension service once a year. If you're racing for points then do at least one oil change mid season. Remember that if you wad up the bike the suspension needs to be serviced and checked for straightness.
Street riders: While street bikes never create the heat and stress that comes from racing, suspension service is very important for proper motorcycle handling. Your suspension should be serviced every 2 years or 24,000 miles. Most stock suspensions needs a first service after 7k to 10k miles. Stock oil is low quality and breaks down quickly.
Classics: If your bike sits around the garage and only is ridden on sunny days then you should bring it in every 3 or 4 years. Moisture and dirt contaminate the oil. Nitrogen leaks out of bladders. Fork legs corrode. Don't have a get off because the bike is only ridden now and then. Your bike will thank you.
Crashing Sucks!!! Face it! Nobody wants to fall down. The single biggest problem that I see is crashing. It doesn't matter if it is a low side or a high side. It doesn't matter if it looks fine. It's the stress on the suspension. Especially the forks! If the handlebar touches the ground any torque value inside the shock or fork is void. The forces that a motorcycle experiences in a crash are extreme. Even a simple low side. Parts come loose, parts bend internally, seals and bushings fail. It can create a dangerous situation in the future. We all know the cost is high. Don't put yourself in danger.
Service your forks and shock after every crash.