Helmets: narrow head, help needed - how wide (in cm) is your bmx/urban helmet?

Hi,
I need your help - I am about to finally buy a helmet as I will restart with BMX racing and they usually don't let you use the track without a helmet - but all I tried do not fit, they are always too wide for my rather narrow 58cm head. Those I tried were always 21cm wide outside, no matter what brand, but would be fine at 20cm or less (the padding/EPS is almost always the same thickness, so it's fine measuring outside). I can't buy a smaller size as it would be too short. After talking to the clerk, I learned that this seems to be a widespread problem.

I wonder if everyone here who reads this and owns a classic-shaped skate/bmx/urban style helmet (please, no aero road bike alien brain stuff) in a M-L (58cm) size could let me know how wide their helmet is (measured outside, at the widest point, usually near the strap mounts).

I start with:

TSG 'BMX/Skate', labelled size: "L/XL (57-59 cm)", outer max width: 21cm
Giro 'Section', labelled size: "M (55-59 cm)", outer max width: 21cm
Bern 'Macon EPS', labelled size: "L (57-59 cm)", outer max width: 20.5cm (that one fits actually best right now)
TSG 'Evolution', labelled size: "L/XL (57-59 cm)", outer max width: 21cm (this one had a really awkward fit)
Bell 'Local', labelled size: "M (55-59 cm)", outer max width: 21cm

please add more!

Specialized and S Works helmets are narrow. My medium Evade is 15.5cm across on the inside. Specialized Echelon is the same fit.

If Met do one worth looking at.

I’ve got a narrow 58cm bonce and their road lids pinch the sides of my forehead as they’re that narrow

pinch the sides of my forehead

that's exactly what's so hard to find, but what I am looking for!

I have now also ordered the TSG Evolution, the Bell Local and the Bern Macon, will measure them as soon as they have arrived.

added the Bern Macon EPS

Bluegrass Superbold has a ratcheting retention strap thing a’la most modern mtb and road helmets so doesn’t rely on foam padding for fit. Might be worth a look.

Added Bell Local and TSG Evolution.

Verdict: apart from the TSG Evolution that had a really horrible fit, the other 4 helmets were fitting well, but the Bern Macon was really the best of them all, and the only one below 21cm outer width = the lowest visual profile. So, this is the one I am keeping and it's really close to perfect. Also, the strap material of the Bern is better than the rest. While it's probably Nylon like the others, the Bern straps are somehow more heavyweight and with a smoother finish, simply feels nicer.