I have a small @ 174cm (5 8 ish?? 5 9 being generous!) – it was sold to me as a medium, then claimed to be a small-medium (no such thing AFAIK).
It’s on the small side for me (and I prefer MTBs to be on the small side) and I have to run a long stem. Will be getting rid as I have finally accepted it’s too small… unfortunately Plan A of the Tripster is now up in the air as there’s no stock @ Freeborn 🙁
However – on the plus side – it’s a riot. I had to build it, and then even knowing and feeling it was too small I have it 2 years later. Great fun bike, as good a hardtail as I’ve ridden, if you like sproing (which I think you do else you wouldn’t look twice at it).
I think small, with a short stem would work for you
EDIT: Forgot to add, if you’re interested, complete or frame only or any combination of bits drop me a mail. Running rigid with carbon Bonty Switchblades at the mo, but also have some slightly shonky Rebas it worked well with.