I've carried a spare around in the tail section for years and it came in handy today as my bulb blew.

I'm gonna stick with halogen, but there so many on the market these days. 

Which do you recommend?

Hi Bonzo,in the dark depths of Yorkshire BOSH /OSRAM works for me with a twin
headlight setup,any BRIGHT ideas anyone

I use the Osram/Sylvania bulbs from the local auto parts shop.  I stick with the stock wattage since the high output 100W bulb that came with the bike melted the connector and welded it to the bulb.  Boy, was that fun!  If you do go high output change the connector to ceramic.

LED and HID bulbs aren't compatible with the optics of the old K bike headlights yet.  They generate a lot of scatter that annoys oncoming drivers at night as well as putting a lot of light away from where you want it.  They're getting better, but still not perfect.

Osram Nightbreakers FTW!!! Phillips Xtreme if you can't get the Nightbreakers.

PIAA Xtreme White Plus 4000K

Best thing you can do for your headlights is to add relays. I wired from the OEM headlight socket to the relays and from the relays to a new ceramic socket. I've just upgraded to a 100W high beam a couple of day's ago when my 20 year old globe blew low beam.
Regards Martin.

Headlight relay stuff if you chose to add one

http://easternbeaver.com/Main/Wiring_Kits/H4_Kits/h4_kits.html

http://culayer.com/product/matchbox-headlight-relay/

http://www.motobrick.com/index.php/topic,4962.msg30932.html

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