Originally Posted by mstateglfr

The Topstone uses a threaded bottom bracket. Its called an English threaded bottom bracket, BSA bottom bracket, or BSC bottom bracket. All mean the same thing- the bottom bracket cups thread into the frame. Its a really simple and effective way to attach a crank. So find the crank you want to use, then find the bottom bracket that matches it while being threaded and meant for a 68mm wide bottom bracket shell.

If the crank you want to use doesnt have a threaded option, there are most likely aftermarket workarounds by wheels manufacturing or praxis.