I bought a pair of these...
30W 12V 3000LM CREE T6 LED Driving Fog Light Lamp Rally Ranger 4x4 Dirt ATV | eBay
and one of these....
Slim 3 Keys Single Color LED Controller Dimmer 5 dynamic modes 6-level speed UK | eBay
and two of these
LMA Relay Standard On/Off 5 Pin 12V 30 Amp | eBay
( actually I used proper KTM sealed ones, but you get the idea)
and robbed bits from one of these....
YAMAHA YZF1000 YZF 1000 THUNDERACE RIGHT RH SWITCHGEAR SWITCH CONTROL | eBay
Then mounted them like this
then wired them up so the light switch has three positions:
1. All lights off
2. Standard lights and LEDs bright on main beam only
3. Standard lights and LEDs dull on dip, bright on main beam
and they work rather well :)