Extra rattly noise..

Hello everyone....
Hope everyone has had a little ride out on this half decent day... I'm looking for a bit of advice?
My mate and I went out for a bit of a coast road ride out last weekend, did at least 60 miles... everything is cushty, except that for the last half hour there appeared a rattly noise. This noise was akin to the stand springs rattling against the exhaust (which it didn't have for the first 5 and a half hours). The bike hasn't missed a beat all this time since. And today I've done another 40 miles, the noise is still there, hasn't changed its tone or created any extra vibration.
I have never changed or checked the bearings but have put a 150 5 port and sito+ on which is massive upgrade from standard in my book.... does pull well, which also hasn't changed in any way, so any heads up to what this may potentially be would be greatly appreciated. I have checked the stand springs already obviously and everything seems the same as always.
Cheers in advance.
Hope everyone has had a little ride out on this half decent day... I'm looking for a bit of advice?
My mate and I went out for a bit of a coast road ride out last weekend, did at least 60 miles... everything is cushty, except that for the last half hour there appeared a rattly noise. This noise was akin to the stand springs rattling against the exhaust (which it didn't have for the first 5 and a half hours). The bike hasn't missed a beat all this time since. And today I've done another 40 miles, the noise is still there, hasn't changed its tone or created any extra vibration.
I have never changed or checked the bearings but have put a 150 5 port and sito+ on which is massive upgrade from standard in my book.... does pull well, which also hasn't changed in any way, so any heads up to what this may potentially be would be greatly appreciated. I have checked the stand springs already obviously and everything seems the same as always.
Cheers in advance.