Thanks Aardvark,
I love trek bikes - I have a Trek 7.3 and love it to bits, really comfortable and feels very safe. The bike I am thinking of having converted is my step through Trek Navigator 3 which is like a comfortable armchair but quite heavy and up here in Biddulph, I do notice the hills. Since I posted, I have bought the ex demo KTM machine. I've been out on it and love it so far! Thanks for the offer of letting me try - it's more important that you are happy with the conversion; however, I too am of dwarf size (5'4" which used to be considered average for a woman until everyone put muck into their shoes).