Im sure its not the gearbox i can change gears without any issues and it feels fine. Just getting worried with the clanking rattle getting louder and more common. Seems to be worse when i pull the clutch in at under 10mph and let the bike coast. It sounds like the rear sprocket might be distorted or at and angle but if it was that it would be making the sound all the time.

Brains melted for one day fingers crossed it will get me to work tomorrow :)

Main reason i got this bike was for something that would be reliable and simple to work on. Guess thats gone right out the window now haha

knocking noise
 

check your main stand has not lost one of its locking nuts, it does knock on the pillion foot rest on a bumpy road. Steering head bearings collapsed very loose?
loose rear sprocket, knackered rear shock (very unlikely). generally check all major bolts on the frame. You will find it eventually.

Cheers for the advice I really appreciate it. I just replaced my steering head bearings about 1k miles ago. Ive not re checked them since so i will have a look and check to see if there two lose or if there goners.

I will re check my sprocket the spacer that goes in that side is very lose i think that might be the main cause tbh.

The previous owner had a chain snap on him and it destroyed the chain guard and also badly scored up the sprocket carrier. Found a piece of the chain guard hiding behind the rear shock the other day when trying to find the cause of this it was badly chewed up.

It does feel like something is possibly lose. A few weeks ago my side stand almost fell off the two bolts almost totally feel out. The joys of motorcycles :)

i went through the obvious nuts and bolts when i got my bike. Shouldnt have been surprised that things were loose..tis a big single after all.

Yeah shouldve known better. I went from a silky smooth triumph scrambler to the 660 and apart from this i have not regretted it.

Happy to report this
I changed the cush rubbers and gone is the noise, thank goodness for that
So, I'm sorted, also changed rear break pads

Thats great mate glad your all sorted.

Think my gearbox is wrecked had to limp the bike home. Checked my oil and was way under what it should be. Had to put 800ml to get it back up to the full line. Only checked my oil about 500 miles ago and was bang on the full line. Checked today and it was way under so looks like ill be paying for my gearbox to get striped and checked. Ive probly done some serious damage so a lesson learned check your oil level.

Are you saying the drop in oil level has caused a gearbox fault, or are you saying a gearbox fault has caused a drop in oil level?

Do you know where the oil went? Any obvious leaks? Is the engine burning it? It must have gone somewhere? You really should ascertain this before you go any further down the line of condemning components and potentially spending what could be a decent wedge of cash.

I am obsessed with looking after my bikes last checked my oil 500 miles ago and it was on the full line. I changed the oil and filter about 2k miles ago there was no metal shavings and the oil i drained look great. I ride everyday and cant afford for them to get damaged by not servicing or looking after.

I have zero leaks and the bike runs great not burning oil or making any noise (apart from when its rolling with weight on it somewhere near the front sprocket i think).

I have never had any experience with a gearbox going on a bike.

Totally out of ideas im a DIY mechanic not a prof. I can do all the basics but when i comes to something like this I feel its best to get a professional to take a look.

The oil drop really worries me i didnt think for a moment to check it lesson learned.

Cant find any info on this anywhere on the net. I dont know why the oil has dropped or if this has happened to anyone else.

I ride 100% on road with road tires the bikes only got 18k miles on it and its been serviced on time. Im not red lining it or hitting the rev limiter so completely in the dark here.

Now i need to find a way to get the bike to the garage to get it checked over.

Still, if it ain't burning it or leaking it, it must have gone somewhere? Is there a lot of oil in the airbox drain tube? Have you taken the airbox side cover off (LH) and had a look inside? Most of the time "missing" oil ends up in there.