Riding back from work last night and ...
I didn't feel at all confident. I start to lean and the damn thing's understeering - I compensate for that and it wiggles like a mad thing at the back.
Sure enough and as expected, an examination at home of the back tyre (with a few hundred miles on it) shows a shiny new nail buried in it. I swear I deal with more nails and screws than my local B&Q. Still, I refuse to stop filtering - even though I'm sure it's the reason I pick up so many of the blinking things
Off to CMW tomorrow to see if it's repairable.
Rant over, thanks for "listening".