Help a newb starting (H2 pick the right geometry parts?)

[Changebiker]

Hi folks,

I have a frame with which I'd like to build my bike.

Previously I've just built by swapping parts from an existing build but by bit, hence I had a real life experience with the existing geometry and what I might want to change there.

Now without this try and change I'm a bit lost how to pick the geometry relevant parts - especially fork, but also the rest.

I have the frame and another bike I rode and liked and would like to emulate as good as possible geometry wise on the bike stats webpage.

But that's where I'm stuck - what now? How to learn what fork angles etc.?

Could you give me a little spin into the right direction?
That'd be amazing!

Thank you so much!

[00Garza]

What frame do you have? Can you find a geometry chart for it?
Start with that. Most frame manufacturers will tell you what size fork to use with it.

[Changebiker]

It's a bit of a special case as I wanted a foldable gravel bike. 
So the frame is one of the few folding ones available: 
https://www.changebike.com/change-mountain-folding-frame-df-933b

The bikes normally built with this are those, one with suspension, one without, fork length axle-crown is 460mm: 
https://www.changebike.com/change-mountain-folding-bike-df-912b](https://www.changebike.com/change-mountain-folding-bike-df-912b

What I learned about the frame/fork: 
tapered-headtube (1-1/2 to 1-1/8) and geometry (it expects a fork with a 460mm axle-to-crown height) 
head tube angle is 71 degrees

Someone else who built something with it was apparently using a fork with a-c of 398mm, but as a pretty tiny person.
A company that was building those into gravel bikes installed either road (380mm) or MTB (465mm) forks on their bikes, so also the short ones seem to get not too twitchy in steering (i hope).

The bike I'd love to emulate is this one in 53cm frame size 
https://gravelbikedatabase.com/bikes/2024-rose-backroad-al-grx-rx400/

Though what would that mean for a-c length, offset,rake and trail with the given frame?

I tried to get an much geometry data as possible and put both in a geometry tool. 
https://bike-stats.de/en/geometrie_vergleich?Bike1=Changebike_Flatbike%20Road%20Warrior_2024_17&Bike2=Rose_Backroad%20AL_2024_53

[Leo.D]

 best path: find a rigid carbon fork with a 460mm A-C and a tapered steerer (1-1/2 to 1-1/8). but any rigid 29er fork around that length will preserve the intended geometry. Once the fork is locked in, stem length and bar choice become fine-tuning rather than compensation.