Thank you for getting back to me.
Sorry, what I meant was which file and line of code specifically do I need to edit to adjust the mobile menu settings.
The site is currently here: wicketts2.co.uk/thephoenix2/
When I shrink my browser window the menu goes on to two lines and then eventually switches to the mobile menu. What I would like is that if the main menu fits on one line then the normal menu is displayed but as soon as the menu goes to two lines, the mobile menu is activated.
Is this possible?
Many thanks for your help so far.