Originally Posted by
Winfried
Yes, a skinny spanner, and a regular adjustable/crecent wrench.
No Brompton user in the audience who could confirm that small play should not be there on a well adjusted bike?
I know what a loose headset feels like (annoys me to no end), and I can confirm that it is not "felt" on my 2019 Brompton while holding the front brake and pushing.
Also, make sure to check that your front hub and wheel are secure, and that you are not feeling the play in the latching mechanism for the rear triangle.
Is it not possible for you to take it back to the shop that replaced the headset?