Well I made it. :-) The first 25 miles were very easy (a sure sign of danger ahead I have now decided) and I stopped at a delightful Bistro called the "Bridge Cafe"
http://www.bridgecafe.co.uk/ to indulge in high octane coffee and a muesli and coconut flapjack both of which were delightful I must add.
Fully sated I started the ride back. Within 10 minutes I thought I had a flat or there was something seriously wrong with the bike. I felt like I was riding in mud. I had around 10 mile of this and was contemplating phoning for a pick up when I saw two "road cyclists" who had passed me earlier sitting in a layby. They commented on how hard the climb was and only then did I realise just how steep the road was. This made me feel a hell of a lot better and on I ploughed.
At around the 43 mile mark I felt a rush of exhilaration as I realised I was going to do it.
The only downer on the day was almost being run of the road by a speeding BMW whilst on a trail section of the ride within 2 miles of my home. I was so furious I called the police and was still on the phone to them when he passed me again. He was highly apologetic so I decided not to take the incident any further this time.
All in all the ride took around 4.5 hours so not bad for my 1st attempt I feel.