Legal regulations for eBikes

Hey everyone,

Been lurking for a bit and finally decided to jump in! I'm planning out a custom build – thinking a mid-drive on a beefy hardtail frame for some serious trail riding and commuting. My main concern, though, is navigating the legal side of things, especially with custom power setups.

Does anyone have experience with how regulations (like class limits, motor wattage, or top speed) apply to a DIY eBike? I want to make sure I'm building something awesome but also street-legal, or at least trail-legal, without running into trouble. Any tips or resources for understanding the rules for custom builds would be super helpful!