Monday, February 6, 2012

Classic bicycle taillights

Luxor Le Martelé taillight. Photo by J Ferguson
I love classically styled bicycle taillights, especially those of the French persuasion.  I have a handful of Luxor tail lamps waiting for the right project to come along (yes, I'm the type that would build a bike around a taillight).  I just discovered this gallery on Flickr dedicated to curating photos of both vintage and handmade taillights.  As well, there's this great Japanese site that has examples of classic lights from Radios, Luxor, Soubitez and JOS.

Unfortunately, modern taillights are invariably plastic and utilitarian in nature.  Compass Bicycles had a recent post bemoaning the indifference to elegance in contemporary taillight offerings.  If you want a nicely designed light suitable for your modern classical build, you're looking at acquiring something vintage (these options from Kimura notwithstanding). If you're into classic randonneuring bikes, then vintage options can get very expensive.

Although I'm partial to the fender-mounted teardrop-shaped Luxor lights, I also really like the JOS tail lamps, especially the Fu model.  Here is a beautiful example from Flickr:

JOS Fu taillight. Photo by spoke sniffer.

It occurred to me that the symmetrical design would lend itself well to CNC machining. For fun I drafted up a concept:

This would obviously be equipped with an LED, so the protruding bulb holder with it's knurled binding post isn't required, although it might be nice to incorporate it.  The bracket might be a bit of a challenge to have made, but the body could be turned on a lathe without much trouble.  The lens, on the other hand, would have to be injection molded, which is associated with high setup costs for unrealistically large volumes.  Perhaps a 3D printer could produce something that might work.  For now, my classically inspired taillight design will have to remain in silico.  What do you think? Does the world need a new taillight?


Anonymous said...

As someone that bothered to hand carry Kimura bullet lights and reflectors back from Japan when they were unavailable here, I'd say the world absolutely needs a new tail light and new headlights as well. While we currently have plenty of light, we are still lacking in beauty, grace and a compelling reason to squat down and take a closer look at the small globe that lights the road. In the meantime Compass Bicycles at least gives us the option to retrofit a dearly held vintage model with a modern LED bulb.


Joey Korkames said...

I've thought about making my own Frenchy taillight as well that would look good on a fender/rack/seattube.

You can mill, cast, or spin the housing. All of those paths require heavy machinery, but i think spinning would be the simplest route (if you can find an old heavy wood lathe and outfit it with a spinner's tool rest) and would produce little tin cups all day long.

For the lens, I looked at cheap-ish motorcycle signal lights but they are all too big and just don't look good. Casting your own lens can be done with a ~$100 kit.

minisystem said...

Joey, I was just looking at that lens casting kit as I was researching this post. I suppose getting a positive machined out of aluminium and using that to make your mould might be reasonably economical. The results do look impressive! I've also been looking into spinning, which would produce probably the lightest and most elegant result. However, I don't really know how to design a shape for spinning and am unfamiliar with the additional stamping, bending or folding steps that would be required attach the lens and mount the internal electronics.

Joey Korkames said...

here's a wood lathe conversion kit, showing the requirements for converting a used lathe. I've also read that old/cheap bronze-bushing machines are perhaps better than ball-bearing spindles for the leverage work involved in spinning.

for the design, I would say to make the main body as a cone that you can glue your (very awesome, imho) circuitry and collimator inside of, and to make a lens bezel as a second piece, which can just be a very short cup that you drill a hole out of the bottom that's large enough for the protrusion of the lens but captures the lip of it. the bezel should be a slightly large diameter than the cone. drill a hole in the side of the bezel and tap it to accomodate a grub screw, which will bind the bezel to the body.

google sketchup could work for this kind of thing, but I find the idea of wood spinning most appealing because your freehanded wood prototype becomes the production mandrel/form - no need to reproduce precise cuts from pure instructions as you would with turning down or milling raw billet.

this is just all spouting off of course, i'd like to see someone (or myself) try this. on flickr, i've seen a Peirera and a JP Weigle with custom little dynamos on the seattube, not sure if they spun them or turned them.

Joey Korkames said...

and to offload more of my notes to your blog, here's some info on sourcing your own lathe conversion parts

I think there is a good amount of demand for bolt-on metal lamps, anyone with a classic bike and a dynamo hub. Most consumer LED bike lights work great until the chintzy plastic casing and bracketry fails from real-world use. The old lamps probably had less such issues, and they were positioned in more illuminating and less obtrusive places, instead of the top of your handlebars.

minisystem said...

All good ideas Joey. It's looking increasingly likely that a lens could be fabricated by 3D printing for testing and that a soft moulding technique could be used to produce the lens economically at low volumes. Still researching, but have talked to a couple of 3D Polyjet printers that say they can fabricate a clear prototype with appropriate colour tinting.