Hey guys, I have a canyon ultimate cf sl that is a size small that I bought a couple of years ago. I want to switch over to the endurace due to comfort riding long rides, plus I rented one through rapha and it was amazing. After inputting my height - 5 feet 8 inches - Inseam - 30 (jean size), canyon suggested I am an XS, which sounds a bit small to me. I wondering if anyone here have the same metrics as me and have either a small or xs?

Inseam isn't your pant size. It's snug in the crotch to the floor. I don't care if you wear shoes but don't have stiletto's on. Most will want no shoes.

I use a carpenters steel tape measure. Holding the body of the tape measure snug in my crotch and aimed at the floor, I extend the tape to the floor. Then I add the width of the tape measure housing which is usually 3.25 inches.

There is no standardized size for what mfr's call S, M or L or even centimeter sizes or inch sizing. So unless you can try it on you'll probably should go by the manufacturers guidance until you know for certain. And that will be pretty hard to do over the internet.

Perhaps call their phone number and talk to the rep about your concerns. I'm sure it's probably in their top 10 of questions ask by prospective customers.

And they can tell you how they expect your body to be measured.

Follow the directions on the Canyon website for how to measure yourself. Don’t ask a website full of half-wits what size bicycle you should buy.

You rented one through Rapha which was amazing. Doesn't that tell you which size is best?

Anyway, I could call a frame size XXXS or LLL. Doesn't matter. It is the frame stack and frame reach which you start with / compare to.
Include frame standover, so you don't have any issues straddling the bike. (Standover can vary, even if the stack and reach is similar).