Every helmet I have tried on has the same issue: if I push straight up on the chinbar the whole helmet slides back to show my chin. Even with a fully tightened chinstrap some slide back to the point of almost showing my nose. Have I just not found the right fit yet, or is this really how all full face helmets behave?
I'm looking for a lightweight breathable fullface, that's beefy but can still be pedaled in. My head is 55-55.5cm depending on where it's measured so I'm right in between a lot of brand's small and medium sizes.
So far I've tried
Fox proframe rs: I heard it's good for oval heads, but both the small and medium slide way up.
Bluegrass vanguard core: the chart says I should wear small, but the straps and boa are kind of a pain to maintain when putting on. Slides up the least so far.
Tld stage: small barely fits and slides way up. Chinstrip would not stay tight.
Leatt gravity 4.0: small slides up
Leatt Enduro 4.0: the removable chin bar sounds ok, but looks far too thin. Small slides up
Lazer cage kineticore: small slides up
Lazer cage: medium slides up
I'm feeling lost at this point