So I’m thinking of going to twin headlights on my little chopper thing, one as high beam one as low beam.

should be straight forward.common earth to both,providing it is not a negative switched circuit,earthing somewhere on the main frame [or existing head light earth ] and high beam wire to the light you choose for high,usually the top one and low beam will be the other.if these lights are the same and the low beam goes out when high beam is switched then you probably wont see any difference unless you use a higher wattage globe, as the lense's will be the same.but if low beam remains on at the same time you will get a little more light  but of the same pattern.cheers.

Thanks guys, these are the lights, as for the bike and wiring it’s a late 70s XL, headlight is a basic H4 based thing.. pretty standard.

Thanks guys! Was hoping it would be that easy!

Mr Mow, I am far from knowledgeable when it come to auto-electrics, but to to make things simple I would wire them as one light on at low beam and both lights on at high beam. Maybe adjust the the direction down and possibly the bulb output on the low, that might just be my lack of knowledge ?.

Sorry, should have read the entire thread first, as per what Bruce said.

All worked as advertised! Thanks guys!

you could fit a blocking diode to the low wire,current only passes on way,this will allow low beam to switch on but no current in the opposite direction,then connect a wire from hi to low with another diode to allow current from hi to connect at the light side of the low diode but blocking low current to the hi light....not simple but should work....if you have room for a lot of wire and bits,well seems easy to me.cheers