I have a possible problem with my CBR. I am hearing this grinding sort of noise when I pull in the clutch lever while riding which gets a bit pronounced when I let go of it and right before the clutch engages. The noise is pretty faint but audible with the clutch pulled fully in, especially when riding as I haven't been able to hear it with the bike on the centre stand-think the helmet helps in filtering ambient and exhaust noise. But the noise is pretty much audible when I slowly release the clutch lever and it is at the cusp of clutch engagement. It's like some bearing is shot or something with a 'krrrrr' like sound coming from somehwere in the bottom of engine, not really sure if it's from the clutch side or left of the engine. I don't feel any pronounced vibrations on footpegs at any point though I do get these rare rattles from the gear selector while slotting into 1st from neutral, especially when the oil is not very warm and I haven't been firm with the shift.
Don't think it's the chain as I have heard this after applying a good coating of Wurth chain wax on my 2000 mile old chain, besides my scottoiler is always at a generous setting and chain slack is within acceptable range.

 

If it was me I'd first check adjustment. It could be dialled out, you never know till you try. That would be nice wouldn't it, a simple fix lol but I would already be getting ready to pull the clutch cover off for investigation.
It could be a number of things but I'd be worried that I could either damage something further or my issue could cause a lock up. So it would be kind of a priority !
The clutch could be worn out, could be the clutch pressure plate hanging off who knows but get in there, strip it and check everything carefully.
If she's not engaging 1st without you feeling "taps" on your foot all the time then something's wrong.
Best of luck mate.