Vintage DynoHub and headlight, modern B&M taillight?
 

Just wondering if I can use a 1950s SA GH-6 DynoHub with a period headlight, and a modern Busch & Müller Toplight Line Plus taillight...has anyone used a setup like that before?

I haven't done exactly that. I have used antique bottle dynamos and connected them to modern lights. I believe they make more power than the old Dynohubs. I think the hubs put out about 1.8 watts. That may not be a deal breaker if you don't require the lights to come on fully at low speed. Modern lights are super energy efficient, so it may not be bad at all. I say try it and report back!

I'm not sure how intact the existing taillight wiring (to the original taillight, which is missing its internals) is, but might try splicing a new wire to the end of it. I want to keep as much of the "rat rod" look of this bike as possible.

http://img.photobucket.com/albums/v8...119_140818.jpg
http://img.photobucket.com/albums/v8...119_140913.jpg

I'm with Tom... haven't done it, but think it should work.

The new lights tend to be a bit more efficient than the old incandescent bulbs, so the prospects are good. Of course, the Dynohub is lower power than more conventional dynamos; 1.8W vs 3W, so it seems likely that the Dynohub systems might have used a less powerful taillight too.

How is the performance of the vintage headlight with the Dynohub? I've got a good bit of experience back in the 70's and 80's with marginal headlight designs combined with a 3 watt bottle dynamo. It was good enough for the time, but just horrible compared to anything modern. If it was me, I'd be looking for a way to sneak an LED into that headlight. :)


Steve in Peoria

The current headlight is basically useless as far as being able to see with it, but it looks cool. I wouldn't be opposed to setting it up with an LED of some sort, if it can be made to work well with the parabolic reflector (which really needs to be re-silvered). Something I read earlier does make me wonder, however, if perhaps I have a bulb that's less than ideal for this hub in it.

Ok, I just tried the new taillight with the vintage DynoHub...it comes on, but not very bright. Also, it appears that there's a break or short somewhere in the existing taillight wire, since it won't come on if I connect the new wire to that. It'll come on if I touch it to the terminals on the hub itself, though.

regarding LEDs... retrofitting a high power LED into the incandescent lights is problematic. The simplest path is generally to use the Reflectalite LED bulb that is built into the base of the incandescent bulb. Haven't used it myself, but I've heard some good comments.

REFLECTALITE LIGHT BULB FINDER

If I ever run out of things that need to be worked on, I've got an old Union incandescent headlight that might be fun to retrofit with a proper 3 watt LED. There are a variety of technical hurdles that a huge pain... it's rarely a worthwhile project.

I haven't used a Dynohub, but considering how hard it could be to find a proper bulb for a 3W (or 2.4W) headlight, I imagine it is only worse for the Dynohub. To be as efficient as possible, the 3W (and 2.4W) bulbs were designed to have a life of only 100 hours or so. i.e. they burned bright, hot, and briefly! A bulb with a longer life would be dimmer and yellower. You might scour the web and stores to see what is available in the bulb base style that your light uses.
Or see if a bike shop has an old dynamo bulb that fits? Can't hurt to try.


Steve in Peoria

I was researching some of this stuff a while ago (LED conversions of vintage lights for use with vintage DynoHubs, that is), because I also have a 1930s-40s 8-volt DynoHub that I want to use with a bike of the same age. What I learned then is that most LED bulbs don't tend to work very well with parabolic reflectors. I did find some that were sort of a "tree" or cube of LEDs, though, so that they would at least theoretically work better with that type of reflector....but then there's the question of getting it to work with the 8-volt hub.

the mis-match between the LED's radiation pattern and that of the incandescent is definitely an issue. You'd get better results by aiming the LED rearwards at the reflector than aiming it forward, where only a small percentage of the light will strike the reflector.

The Reflectalite uses a 'side emitting" optic, which aims most light to the sides. This does use some of the reflector, which forms the light into a beam. I used an early Luxeon 5 watt LED with the reflector from a Union headlight back when the Schmidt hub dynamo first came out. It was an improvement over the incandescent dynamo lights of the era! However, using a more modern LED with a good molded "TIR" optic produces much better results.

The other issue with installing a proper 3 watt LED is providing cooling for the LED. In a perfect world, you would provide some aluminum to conduct the heat from the LED to an external heatsink. Adding an external heatsink to a vintage or retro headlight is often not an option. A second option would be to conduct the heat from the LED to the steel housing of the light. It's not optimal, but might be good enough.

The Reflectalite avoids this issue by only using about 1 watt of power. With a 3 watt dynamo, that would be a waste. With a Dynohub that is also trying to power a taillight, it might be perfect. :)


Steve in Peoria

Cool, I'll look into it again. May also need to see about re-silvering the reflectors on both of my antique headlights.

I gave my answer too hastily before reading your original post thoroughly. The modern tail light will probably consume less power than the old one, leaving a tiny bit of extra power for the headlight. But the headlight is probably lousy. Also, modern lights have voltage regulation built into them, but your old headlight has none. The extra bit of power might increase the likelihood of burning out your bulb.

As @steelbikeguy points out, a replacement bulb that is LED may not work well at all. I tried one of those in an old two-D-cell type flashlight, and the result was terrible.

B&M makes headlights that are styled like antiques, so maybe you should try one of them.

I did a quick search having seen some nice modern, but retro looking, dynamo lamps from B&M, and the BUSCH + MÜLLER LUMOTEC CLASSIC T SENSO PLUS seems to look great for about $30 to $45 USD. Other various options are available, as well.

See, for instance, here.

I've seen others that are a bit more like the 'original' on your rat-rod contraption, but the beauty of the rat-rod is that it was older stuff upgraded by the owner...

Speaking from personal experience,,

Yes, a B&M tail light will work fine with a vintage dynohub, and any type of headlight.
Yes, a reflectalight led bulb will work in vintage headlights and be an improvement over an incandesant bulb, but not comparable to modern dyno lights. ok for being seen, but barely functional for seeing.

I have this $23 light and highly recommend it, at 40 lux its much brighter than vintage lights with either type of bulb, has a built in standlight, and state of the art optics like B&M lights.
https://en.hollandbikeshop.com/advan...eywords=356335

I also have and recommend this $17 retro tail light. The headlight, and tail light are about $75 with shipping.
https://en.hollandbikeshop.com/bicyc...parking-light/

The mentioned lights on my Chinese, Dutch, American, Indian franken-roadster.

@kickstart, those are pounds (sterling), not dollars.

That is what the site shows by default when in English with 19% VAT included, One needs to change shipping location to United States, and choose USD to see the actual prices in USD with VAT removed. If you don't have an account, it must be done in the cart.

I paid $23.77 for the headlight, and $14.07 the tail light in USD .

BTW, the price shown changes with the exchange rate.