I want to move from 4.5mm threads on my Ross Signature shifter bosses to 5mm so i have more choice of shifters. To do this do I need to get a specific size of 5mm tap or just ask for one for M4 5mm?? Just wanted to be sure because once they are tapped I can't go back....
...if there are screws currently installed on this frame in the shifter bosses, you would do well to take them to some industrial fasteners place and get them measured. I,too, am unfamiliar with M4.5. I suspect there's something wrong here, but I can't exactly understand what it is.
Anyway, I'd hate for you to come to grief over this. If all else fails, just buy and M4 and an M5 machine screw at the Home Depot and use them as gauges for what you have now.