the one that fits, frame size isn't always a good indicator especially as women tend to have differently proportions limbs/torso to men

i've got Doris on a 14" inbred.

she's 5'5"...

inbreds are large for a given frame size....

true, i'm 6'2" and riding an 18" - which still feels very long.

14inch probably, that's what the Missus' HT and Orange 5 are. She's 5'5".

Fit is sooo important - my wife (5') rode a 15" Orange for years and thought it was OK. We then bought an XS Cannondale (about 13" and much shorter top tube - and the difference is fantastic. You can see she is not stretching anymore, much more comfy etc.
Do get a test ride - brands and top tube lengths can very so much.

Varies so much between brands, my medium specialized (17 inch) is smaller than a small cannondale. I'm 5 foot 4

Agreed top tube (virtual horizontal) measurement is the most important thing. Frame size is so arbitary depending on where the measurement is made on the seat tube.

Depends on the bike. I am 5' 4". My 16" GT was too big my 14.5" Anthem is a tad small so I had to move the seat backwards and use a longish stem. But I could ride a 18" Boardman fine especially with a short stem and by bringing the seat forward. It all depends on the bike.

Aye - she needs to try them. I'm 5'5'' and a little bit and have a Commencal Super 4 medium (16''/17''?) and a 16.5'' Genesis Alpitude...

You are much better off getting the right size frame in the first place rather than compromising the handling (stem too long) or the pedaling (seat too far forward). Also just to mention at 5'5" the bike must have 170mm cranks. I can't believe how many womens bikes of this size come with 175mm.

Mrs carlos is 5'6" and rides an xs Cannondale and loves it.

Does 5mm per crank really matter that much?

it does if you have legs 4" shorter than the average man

ok makes sense they should be shorter, but 5mm?

so an extra inch or two really DOES matter 😯

odanny boy. It certainly does. You ride 175mm I take it - try going out and riding 180mm. You won't believe how do it feels. It not the extra 10mm in diamater anyway it's distance around the circumference of the circle that your pedal travel in. 175mm to 170mm is 31mm less circumference.

5' 4" here, with a 14" inbred frame and a medium Juliana. I also have the saddle as far forward as possible.

Mrs Barnsley is 5'5", she has a small (not sure what that equates to in inches) cannondale hardtail (f5) which fits very well.

I'm 5'2" & ride a Marin Mount Vision (QUAD I version) with an inline seatpost and 70mm stem.

MrsD is 5'4" and rides a WSD Specialized Myka in medium.

Both bikes have a near-identical standover height but the 'reach' & 'fit' are extremely different.
I find the Myka to be way too short and cramped with a very sit-up-and-beg position whereas she finds the MV to be almost flat-backed in comparison.

Women have comparitively long legs, and short torsos, btw.

I always use the effective-top-tube measurement to guage size.
I'm 5'4" and ride a 16" Kona and a 15.5" Dialled... Kona has a 22" ETT measurement, and Dialled 23ish" ?? So I run a 40mm stem on the Dialled - I could probably get away with a little longer.
On an 456, for example, I could probably ride a 16" with a short stem (23" ETT), but would probably go for the 14" (21.5" ETT) where available

...and in road bikes I ride a 20" traditional geo, with a 21" TT.

In short, ignore the seat-tube measurement, and get something 22ish inches across the top. 😀

PS. I thought I should add: I've never owned a women's specific bike - always altered bikes to fit (shorter stems, etc)

I'm 5'5" and have ridden both womens and mens - have found them all to be a bit of a mixture, mainly too short in the top tube.

I would say my current 14" Inbred is about right but my medium Litespeed Ocoee is perfect - geometry spot on and fits like a glove.

Would strongly recommend that a plea is put out to the STW girlies requesting a sit on their bikes.

In answer to your question though, 15" is too short in the top tube and 16" can be too long 🙄