I'm 19 stone, haven't cycled for 2 years and have never done anything like this before. I'm certainly no Wiggo. So why did I volunteer to cycle 170 miles in June?

One of my heroes, Terry Pratchett, died recently of a dementia related disease. He was a remarkable man who wrote some of the funniest and most imaginative books the world has ever seen. He handled his illness with dignity and, as far as I can tell, never complained. He also helped raise awareness of what can be done to help sufferers to lead positive and fulfilling lives. Every peddle stroke will be dedicated to him and all those who deal with this cruel condition every day. Please support my meagre efforts, I'm going to need all the help I can get.