Thanks for the figures re cable pull, I need to get to my LBS tomorrow and get a new inner wire and some outer, then I'm good to give it a go.
I've got a 100 mile charity ride coming up which goes over part of Exmoor, which is quite hilly. I no longer have the legs for such a ride on my 39/53 coupled with 12-23 8 speed. Getting say an 11-28 8 speed brings too many big jumps between spockets, hence thinking about 10 speed as it'll give me more flexability in the 20-28 part of the cassette. Either that or get a compact chainset. Have put out a Wanted thread as I'd like to equip one of my bikes for a hilly route rather than have 2 road bikes with the close ratio stuff that I have as a hang over from my competion days.
Will post the progress
do not despise the snake for having no horns, for who is to say it will not become a dragon?