Headlamp reflectors

[Tom Coates]

The reflectors in my headlights need resilvering - they are the 4 1/2" chummy type. I notice that they seem to have a much deeper concave profile than modern reflectors and I wonder if this is optimum?

I have found reflectors of the right size and a more modern profiile available in the US and was thinking of trying these to see if they might throw a slightly more concentrated beam? However, I'm not sure if the flatter reflector needs to go with a convex lense for them to work correctly? 

They do have the advantage of being significantly cheeper than resilvering the existing units. I have fitted LED bulbs and this has imroved the light output, but they are still pretty hopeless! I'm not expecting a miracle but any improvement is worth having.

[Alan]

Tom. I can’t help with your question, but I’d be interested in your source of reflectors.

[Malcolm Parker]

I would have thought that a deeper dished reflector would give a more concentrated beam.  If the headlamp glass is of uniform thickness, ie is not acting as a lens, then its actual shape should not materially affect the beam of light. It is all about focusing the source of light.   As I understand things, an LED light source is only bright when you look directly at it, so there cannot be much light going back or sideways onto the reflector?   This is probably why LEDs look bright to oncoming traffic but project very little light.

[Charles Levien]

Tom, if your chummy is pre 1929 I guess you will have scuttle mounted lights. These were obviously intended to light up the wings and bonnet leaving the road a black hole. Hence the popular solution ( in the old days) of fitting a spot light at the front to see where you are going.
I cant see how making scuttle lights brighter is going to help but I’m very open to being corrected on this!

[Tom Coates]

I found these https://www.steinertractor.com/ABC320-He...-Reflector which look as if they would do the job.
I have a GE cup so the lights are mounted on the radiator. I have driven a chummy at night and found it safer to drive with them turned off on country roads as at least your eyes can adjust to the darkness! The LED replacement headlight bulbs are basically a   piece of aluminium with one LED mounted on either side pointing at the reflector, the light isn't as evenly distributed as with a bulb but works ok.