I have a fulcrum racing 5 evo which has a loud free hub (like other campy) for about 5 years now. I like the loud noise when coasting because I don't need to put a bell on the bike. On my last ride, I just notice that the wheel has become quite (like a shimano).
Can anyone tell me is that something I should be concerned (and get a bell), or is it just need servicing? I also don't know if it's serviceable because it has cartridge bearings. What is happening and how is it affecting the ride?
It's the pawls riding over the catches that make noise. If you hub was previously "loud" and is now quiet, something is likely keeping them from dropping energetically into the catches. I'd disassemble your hub and inspect/clean/relube.
As others (@Daniel R. Hicks) have noted, the issue is that if the pawls aren't catching, the ratcheting systems of the freehub is no longer working properly. As far as bicycle malfunctions go, this isn't the most dangerous thing that can happen as your brakes will still work, steering is unaffected, just a sudden reduction of power to the road.
Whatever is causing this (dirt or rust most likely) is likely to also have secondary effects, chiefly drag, but also the possibility of undue wear on the freehub. Five years is a decent amount of time for water and road grime to make it's way in. You probably don't need to get to your LBS today, but plan on stopping in this week. They should be able to confirm the cause in a few minutes.
Happy Riding.
I had the same happening to my Fulcrum 5 Evo (I think the set is from 2007) during the second season of use. I contacted the dealer that sold me the wheels and they put on a new wheel and said it was a warranty issue! Your wheel is probably too old for warranty I guess. The replacement wheel has been working fine ever since, now downgraded to autumn/winter commuting rides on the Norwegian west coast (i.e. lots of rain and road grime). - I agree with @Ken Hiatt, water, mud, grime makes its way inside and speeds up the wear rapidly.
