You say you tightened the chain last week.
I'd be looking at that again, as it sounds possible to me that it's too tight and maybe also misaligned.
Put the bike on the centre stand, and spin the rear wheel backwards. It should make a purring noise if the chain tension is good and the wheel is straight.
If the chain is too tight then you'll hear and probably see that it isn't right, and if it's misaligned it will make a consistent clunking sound as it tries to correct itself.
The chain should just about comfortably touch the plastic chain guide that's near the front sprocket when you raise the bottom line of it.
To do all this correctly you need to nudge the wheel forwards and gently bring the wheel back either side using the nut at the back of the swingarm. Don't forget to loosen the caliper tension bar otherwise the right side will not budge.
The notches on the swingarm should be a good guide for either side, but are not always 100% correct plus obviously every bike is different, which is why i find spinning the wheel until it purrs nicely works better in my opinion. You may need to nip up the main wheel bolt before you can attempt to spin it properly though. It's all about doing it gradually, then once you're happy with it you won't need to touch it again for ages once all the locking nuts are tightened too.
On a side note, if i am correct and it is a simple tension/misalignment thing then it's a real quick way of wrecking a chain and sprockets if it's not sorted out promptly.
Bear in mind i'm talking about a chain in decent nick too, if it's dry or has stuck links then that will just make matters feel much worse.
You can check for stuck links by looking at the bottom row of the chain, if any are not totally horizontal then it's not a good sign, although when links are stuck you'll normally feel them bumping through your left footrest.
I'd be looking at that again, as it sounds possible to me that it's too tight and maybe also misaligned.
Put the bike on the centre stand, and spin the rear wheel backwards. It should make a purring noise if the chain tension is good and the wheel is straight.
If the chain is too tight then you'll hear and probably see that it isn't right, and if it's misaligned it will make a consistent clunking sound as it tries to correct itself.
The chain should just about comfortably touch the plastic chain guide that's near the front sprocket when you raise the bottom line of it.
To do all this correctly you need to nudge the wheel forwards and gently bring the wheel back either side using the nut at the back of the swingarm. Don't forget to loosen the caliper tension bar otherwise the right side will not budge.
The notches on the swingarm should be a good guide for either side, but are not always 100% correct plus obviously every bike is different, which is why i find spinning the wheel until it purrs nicely works better in my opinion. You may need to nip up the main wheel bolt before you can attempt to spin it properly though. It's all about doing it gradually, then once you're happy with it you won't need to touch it again for ages once all the locking nuts are tightened too.
On a side note, if i am correct and it is a simple tension/misalignment thing then it's a real quick way of wrecking a chain and sprockets if it's not sorted out promptly.
Bear in mind i'm talking about a chain in decent nick too, if it's dry or has stuck links then that will just make matters feel much worse.
You can check for stuck links by looking at the bottom row of the chain, if any are not totally horizontal then it's not a good sign, although when links are stuck you'll normally feel them bumping through your left footrest.
More people are born because of alcohol than will ever die from it.