Cheers.
It was not on a bike.
I had spent a couple of weeks lifting heavy coping stones for a wall I was rebuilding, putting a cut up car onto a trailer to scrap, and loading big logs for fire wood to deliver to a friend.
Then, one evening, the tendon went POP while walking up the stairs.
Following advice from the good folks at YACF (NHS Direct was busy) I went to A&E and got plastered up for the night. The next morning I was properly inspected and plastered up again. I then fell over, when the crutches slipped in the rain, when I got home and broke my toe on the same leg.
I am now in a Beckham boot until mid August and then physio. It could be the end of the year before I am back to near full strength. It will never be 100% though due to the location of the rupture. Not sure when I will be able to walk unaided, never mind ride, again but hopefully before we get into the depths of winter.