Swapped tyres for a thinner profile at the back, and hey presto no problems with the tyre being jammed into the frame at full inflation.. Of course now the bike just looks plain silly with a big fat free ride tyre on the front, so I will have to find a few moments to change that for a different one as well. If I had the spare cash I would buy some new ones, but as I don't I am robbing them off the old bike. A bike which will set on the work bench of the shed for awhile awaiting a new headset and a pair of forks.
The advantage of the tyre change is that suddenly I look less flashy and a little more "stealth" for riding out with all those fit young dirt jumpers. No-one will expect me to be making big air or downhilling in Scotland every summer. Certainly, not until I have invested in a full face helmet. One very bruised face from a "minor" tumble is enough thank you very much.