AJS & Matchless Owners Club

Having found myself needing a new headlamp bulb I purchased one from the spares scheme, while keeping me legal it didn't provide any focused usable light? taking a closer look I noticed that the filaments seemed to be in a random position to my original (vintage) bulb?

A vintage bulb was ordered on line and fitted. This cost twice the price but is more than twice as effective (can now see the pot holes) this is my opinion, but may be of use to someone, kind regards, Ian.

impressive , if only they made new bulbs like the old ones
I thought it was my eyes getting worse

Good intel...

The culprit.

Sometimes you can pack a ring of tinfoil or shim under a new bulb to improve the focal position to do away with the doughnut effect in the beam.

That's remarkable.

Johnny B

The older (vintage) bulbs have the filaments at 90° to the location notch, and the quality seem very good, the new Lucas labelled bulbs seem to have the filaments at different angles to the location notch, a metal (anti dazzle??) Shield, and look a bit shoddy, this is probably known to all (except me) and yet 12 volt automotive bulbs seem excellent. Long live 6 Volt. Best regards, Ian.

Why not use an LED bulb with BPF fitting.
To be honest I gave up with the candle power ages ago and both of my bike now use LED's front, rear and side lights. They give a fine bright light,
are more robust and take very little power. No need to consider a 12V conversion 6V LED's are readily available.

This bike is now running total loss on the battery so I swapped out the filament bulbs for LEDs.
I thought I would put up a couple of pics for comparison, but the head lamp appears much brighter in the the photo than reality and the beam is not well defined.
They were inexpensive bulbs direct from China and I am okay with them for daytime riding lights, they don't drain the battery quickly, I left the headlamp on main beam and it was still bright after a couple of hours on a 5ah battery.

One thing I have noticed with the cheap LED twin bulbs, ie main/dip or rear/brake bulbs , is that they do not appear to be separate circuits within the bulb. When you put current to one terminal of the bulb it back feeds current out of the other terminal.
On the bike in the photos the main/dip warning lamps would both light up no matter which was switched on. When the brake was used the pilot lamp in the headlamp would come on as well as the brake lamp. It didn't happen with filament bulbs and it's not the first time it has happened when I have put LED lamps in. I had to put diodes in the circuit to prevent it.