Final thoughts before buy
 

I am looking at the Motobecane Fantom CX and I'm trying to decide between 54 and 56cm. I have a 31" inseam and have slightly longer wingspan than height. If I size down wouldn't it be easier to fit than if I size up?

I am with a 32 inch inseam and relatively long arms for a woman and ride a 54 cm bike.

I have a 32" inseam and can go between 56-58. get the 56. (IMO)

Unless you try the bikes for size--Toss a Coin.


(Gambling nevers works though)

In general, yeah, a smaller frame is easier to size up than the other way around, but do note that smaller frames also tend to have shorter headtubes and that will limit the height of the handlebars to an extent. If you are not so flexible, this could be an issue. There's a good variety of stems out there so this may not be a problem. Also, I notice lighter performance orientated stems tend to be from 90-140mm. Your options for a lightweight 50-80mm stem is really limited so I guess this makes smaller frames a bit more attractive to someone who is weight conscious.

The 56cm says it has a 31.29" stand over height. Since you listed 31" I'd say for the 54...