First thing - take out the blown bulb, then take it to a bike shop - some car shops don't sell certain bike fitments - if it's a reasonably new bike it should be a halogen bulb - hang on, would a 50 have 6V electrics? Anyway, take out the bulb and see what it says on the metal bit regarding voltage and fitment - if it's a new-ish bike with 12V electrics a car spares place like Halfrauds may have something to fit, if not, take the bulb to a bike shop to get another - simples! [smiley=thumbsup.gif]