Build advice (2)

I have a Chinese frame 54cm coming in the mail.
I will be adding Di2 ultegra components.
Not all that confident with some of these numbers (from online articles):
11-28 cassette
170mm crank
53/39 chainring
fit is bb86 bottom bracket (two suggestions: bb71, press fit)
Swiss Side Hadron wheels

The terrain I ride is rolling hills. Mont Tremblant in August.
My height is 5,10 (178cm) leg inseam 2,9 (84cm)

Any suggestions would be greatly appreciated!

Hard to know exactly what the right fit would be, but a 54cm frame seems to be in the right ballpark. I’d advise getting your fit coordinates (either from an existing bike, or getting fit at a shop on an adjustable “fit bike”) and make sure your build gets you in the proper position.

Ui2: Great stuff, it’s just tricky to get the electronic stuff integrated into some bikes.

11-28: This is the way to go for most people.

170mm 53/39: Crank length is highly personal, so 170mm is fine unless you have a specific preference. If you can get a compact crank, consider 52/36 chainrings (more versatile for rolling courses).

how compact would you suggest for the crank?

Get a 110 bolt circle (aka compact). You can always put 53/39 rings on it later if you want, but you can’t go smaller than 39 with a 130mm bolt circle.

I personally like 52/36 for racing on varied terrain. It came stock on my Shiv and I’ve been very happy with it. I have a 50/34 on my road bike, but that’s used for more serious climbing and non-race level efforts.