Thanks for all the info and replies on roadie gears for my bike. Now have 11/12/13/14/15/17/19/21 and it's magic to ride with, fitted a new gear cable as well. Took a 12-23 cassette, removed the 23 and put my 11 in from the MTB setup, sweat. Still twidling to get supper smooth changes but it's pretty good, I guess the cable stretches a little to start with. All I need now is aero bars and I'll almost have a proper
tri bike.