Legal regulations for eBikes

Hey everyone,

Been thinking a lot about custom eBike builds lately, especially as I'm planning out my next project – converting an old hardtail mountain bike into a commuter beast. It got me wondering about the legal side of things, particularly with custom builds.

For those of you who've built your own eBikes, how do you navigate the legal regulations regarding motor wattage, top speed, and pedal assist vs. throttle? Do you register them in any specific way, or just make sure they look like they fit the Class 1/2/3 definitions? I'm curious if there are any pitfalls I should be aware of when sourcing a powerful motor for a custom job.

Cheers!