Help: Best Trek Lexa size

[Lira]

Hello everyone!

I'm new here. I've found this forum when looking for information about the best frame size for me.

First let me introduce myself I'm Maria and I'm from Portugal and here bike shops don't really have women road bikes in stock or even unisex bikes in small sizes.

I was lucky to find a Trek 1.2 size 47 on a shop near home as the owner of the shop bought it to his son. I tried this size and it feels comfortable.
I didn't really have the chance to try it for real on a big ride or anything thought.

After checking different bikes and brands I decided my best option would be getting the Trek Lexa SL so went to the same shop today but was confused on what size to get. The owner of the shop told me a Lexa size 50 is equivalent to the 1.2 size 47. I noticed the horizontal top tube is different though, Lexa size 50 has 51.8 cm and 1.2 size 47 has 51.3 cm. The one thing that remains pretty much the same is the reach with only 1 mm difference.

I'm 5´4 tall (162 cm) and have 30.7 inches inseam. Does anyone here with similar size to me has a Lexa or another wsd Trek bike? Which size do you think would suit me better? 47 or 50?

I know I should test ride them, but this is not possible here
The shop will order the bike for me and they cannot return it if it's the wrong size meaning they would be stuck with a bike no one will ever buy (bare in mind there aren't many girls riding bikes here).
Anyway I hope some of you can give me a better idea on what size to get. The shop owner doesn't really seem to be worried about getting the right fit but I sure am!

I have been reading everything I can online but still its difficult because it all comes down to trying different sizes, which, again, is impossible for me to do here.

Any help or hints would be greatly appreciated

Sorry for using centimeters instead of inches, it's really messy for me lol hope I got my height in feet right.

[pinsonp2]

I am 5'5" and have a 31" bike inseam and I ride a 52cm Trek 2.1 WSD and a Madone (H3) 5.2, also in 52 cm. Based on my experience with my Treks, I would think the 50 cm would be the best for you. When I purchased the Madone, my original fitting for size was on a Lexa (had in stock) since the Madone shared the same geometry.

P2

[Crankin]

I am 5' 1" and have a 28.5 inseam. I have a 47 cm Silque (the newer version of the WSD Madone). It fits perfectly. It seems like you would need a different size than me, as you are 3 inches taller, with an inseam that is about 2.5 inches longer.
Did you have a real bike fit?

[Trek-chick]

I am 5" 7" and ride a 54cm Lexa. I have long legs and short torso.