Now that the dark nights are here my work hours mean I spend a lot of time rising to and from work in the dark.

As I live in the sticks this means commuting on a lot of b-roads with very little or no street lighting. I would like to fit brighter bulbs on my Speedfight to help with this.

I'm currently using a couple P43t Halogen Bulbs H4 (12v 35/35w). But these are not as bright as I would like.

Can I fit some higher wattage bulbs and will I need a biger battery to run them?

Stuart, December 2007

Higher wattage bulbs give two problems 1) If the headlamp glass is plastic it may melt with the extra heat (!) 2) A higher wattage bulb will take more energy from the generator - perhaps more than it could cope with. A larger battery would help things a bit, but if the generator can't cope with the extra load then it would simply take longer to go flat. If you do go ahead with a 65w bulb then look for a dimmer tail lamp, and perhaps the battery wouldn't have enough charge for the electric starter if the lamps were used for a while.

John, December 2007