Hi everyone, I’m currently working on a folding bike project where I’m transferring (almost) all of my parts from a BMX bike.
I already have the crank and a bolt on 110bcd spider to use for the build.
Right now, I'm facing a compatibility question about using the 3-piece, 19mm 8-spline BMX crank on the folding frame. My two workarounds are: 1. Euro BB (68mm BSA) — most of them are 73mms except only one brand is available to me: Showke, a Chinese BMX brand. I've seen a reputable local BMX shop selling this brand. 2. 24mm BSA external BB + 24-to-19mm adapters (shims)

My gear setup is 1x6, where current chainline is 47.5mm which works fine with the rear cogs. For context: I don’t do jumps or tricks — this build is just for casual cruising. Which setup do you think is better in terms of ease of installation, maintenance, and future-proofing?

Can i achieve same chainline with external bb? Or internal plug and play euro bb but unknown brand is better?

More info would be handy. What bikes, what cranks, what is wrong with the current cranks on the folding bike? Also handy to know where you are?

Hi. My project is a bmx x folding bike. The bike is a Japanese OEM folding bike. The badge in front says, "fbp since 1946" and decal on top tube says folding street 1946. The bmx donor bike is my old 2013 Sunday Primer. Parts transferred from the bmx are handlebar, and the stem. Other available parts are fork, rims, and crankset. The bmx is a 3 piece crank with 8 spline spindle.

The bb shell is a BSA threaded 68mm wide.

Nothing wrong with the stock crank, but it is my dream to make this bike as much bmx as it can. I already have the crank and a haro spider with 44t chainring.

I'm located in Malaysia.

Be careful trying to do BMX stuff on it. Folding bikes aren't really designed for tricks and such. If I were doing it and I could get a Shimano External Cup BB to work I would do that, they are generally low cost and decent. I don't know the Malay market so well so I cannot speak to availability of everything over there but hopefully you can make your odd dream come true. I would much rather have a more capable bike that is an actual BMX or a sturdy mini velo rather than a folding bike that looks the part but won't handle actual BMX.