You mean when the plates are disengaged? I always get confused on that one. A stock 4 speed cluch has big plates that wobble when the clutch lever is pulled and they rattle against each other and against the 10 studs coming off the inner clutch hub. This is normal and is really noticible when the derby cover is off. But if it is something that has been getting worse and worse. Then it's probably grooves in the studs coming out of the hub which prevent the plates from moving freely. Usually it'll also cause hard shifting that comes and goes. You can buy a kit to just replace the studs but they are a bitch. Your better off buying the whole hub for not much more. Having said that, Are you sure it's not the rear belt that's chirping? Does it only do it when your moving or at a stopped idle too? Reason I ask is that one of my bikes is an 83 FXSB with a rear belt. And that fricking belt chirps all the time no matter how I adjust it. I have the original rear belt with over 100,000 miles on it. I've had that bike for over 20 years. And that rear belt drives me crazy. Fricking rear axle on the right side slides forward about 1/6" and belt chirps. I can set tension, alighment, etc. And it still does it. Rather than replace the two pullys and the rear belt, I'm gonna go with chain and save big$$.
I'm not positive that it is the clutch that's chirping, all that I know is that it's coming from that area. I suppose it could be the belt. It only happens when I'm at a stop and I quickly release the clutch so that I can beat traffic. It's very infrequent. If it is the belt, is it in a bind or would it be slipping?
If your at a stop, it's not your belt. But if your rolling under alot of power from a dead stop, then it could be. Do you have an enclosed primary or is it open? Usually you can't hear the clutch when it's enclosed.