@Jimmuller
First of all can I say, what a fantastic reply that was! - You're really understood where I'm going with the project.
By way of comparison, our longest to date was the London to Brighton, at 65 miles, so, very similar. We are 19 and 20 respectively, and add up to around 310lb (140kg) combined weight.
That information on gears is fantastic, thanks!!!
I am planning on keeping the cranks conventional, but, is there any specific reasoning behind your reccomendation?
We're planning on putting the rim brakes on independent levers, and putting the Atom on the friction gear shifters, which will have been vacated once I move the gears to bar ends: do you think this would work?
Regarding BB replacement, it really remains to be seen what's there once I open them up... I'm expecting the worst though : (
Is there a particular reason you've kept the Simplex deraileurs? Just for the originality? Our rear derailer definitely needs replacing...
I'm a very experience cyclist, and modern solo mechanic, so I think I should be OK, I just wanted the expereince of those who've done similar things to back up or confront my percieved opinions; thank you.
Who needs 'modern', eh?
Will