Upgrading vintage bike lights to use LED and "modern" batteries

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rmwesley
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Upgrading vintage bike lights to use LED and "modern" batteries

This is my first post and to set out my stall, I know nothing about building or modifying LED lights (this sounds like an intro at an AA meeting?).

However, I restore vintage bikes which normally come with very nice, bullet shaped dynamo powered lights.

I'd like to convert the light housing to accommodate an LED and an external "modern" battery pack. Or even possibly a self-contained unit for a small rear red light.

There are projects online which are just Step 1. do this... Step 2. do this... however, I'd like to put a bit of effort in and do some research myself on how to go about it.

Are there any good books or links anyone can recommend as a starting point please. I have "A-level" / first year University Physics (albeit from 30 years ago) so can hopefully get to grips with the technical aspects.

Many thanks in advance for your time.

Richard

sp5it
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Vintage? I would keep them unmodified.

Think of how stupid the average person is, and realize half of them are stupider than that. George Carlin

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rmwesley
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Vintage doesn't necessarily equate to valuable or unique.

However, in general, vintage dynamo lights are fairly pathetic at doing their job of lighting up stuff especially when the bike is stationary at traffic lights etc.

Hence the reason for wanting to make them and the bike more usable, whilst still keeping the aesthetic.

alpg88
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I do not think there are books, as far as links, BLF, CPF, pretty much all there is. but there plenty of info on these 2 forums.  

Now about moding a bike light, there are many ways you can do it, all depends on a particular light you modifying, i understand the whole reason you want to mod is to keep original look, which limits you a bit,  but there is still plenty of room for improvement.  

The best way for us to help you, start with good detailed pictures of the lights, but not just outside, take them apart, and show us internals. When we see that we'll have ideas on how you can mod it. there are many people here who have done something similar.  

Argo
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Hi rmwesley,
i did it: I restore my vintage bike and now it has 2 two lighting systems:
the first lighting system is the original one, with original dynamo and headlights, but I changed the incandescent lamps with led lamps.
The second is equipped with a battery, the cables pass through the frame where possible, at the rear the additional LED is housed in the original headlight, while at the front the new headlight is installed on the handlebar with a mount and a go pro adapter.
It’s all very simple, if you want I can help you modernize your old bike with a very small expense.

rmwesley
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Many thanks for your reply, I appreciate it.

I haven't got anything in at the moment, so expect a short delay until I get my hands on something suitable.

Externally they will typically look similar to this:

Source: Sheldon Brown

rmwesley
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Argo wrote:
Hi rmwesley, i did it: I restore my vintage bike and now it has 2 two lighting systems: the first lighting system is the original one, with original dynamo and headlights, but I changed the incandescent lamps with led lamps. The second is equipped with a battery, the cables pass through the frame where possible, at the rear the additional LED is housed in the original headlight, while at the front the new headlight is installed on the handlebar with a mount and a go pro adapter. It's all very simple, if you want I can help you modernize your old bike with a very small expense.

Thanks Argo. As soon as I get something suitable in, I will post up some pics.

In the meantime, I'll try and find something to rad on the electronics set-up, managing the heat dissipation etc.

alpg88
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electronics is the easiest part,  drivers are widely available, and there are many different ones, hardest part would be proper heat path and optics, your goal is to use existing light body as a heat sink,  however it's shape makes it a challenge, but it is not impossible. 

Argo
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You can update the old bullet spotlight with a LED, I use a led like this and it works perfectly.

It will make a lot more light from the original incandescent lamp, but don't expect excellent lighting.

 

 

Installing a dish, a heatsink, a driver and a switch in that old headlight is a complex and expensive operation, so the easiest and most convenient thing if you want to use the dynamo is to buy a modern vintage style LED headlight for the your dynamo, like this, but even in this case don't expect a lot of light.

 

 

At the front the best solution is a small bicycle headlight with separate battery or with integrated battery, there are some very small ones that make a good light and you can also go down the type of led.


At the rear, on the other hand, it is much easier to install a LED or more led and there is no need for a heat dissipator if you drive the LED well, you just need to glue it into the headlight.

 

slmjim
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What bike?

Wife and I restore & collect Kawasaki Z1's as a hobby. Early to mid 1970s. There are replacement LED headlight assemblies that fit into the stock 7 inch headlight shells that will convert them to LED and retain the OEM look for the most part. If your bike came with a sealed beam or H4 incandescent, that may be the best route.

Much has been written about replacement LED bulbs to fit in motorcycle H4 housings in other bike forums.  Seems there's a thread here on BLF also.  Motorcycle headlight housings differ from car headlight housings in that the reflectors and, especially,  the lenses are designed for beam shape and cutoff needed for a single headlight system.  Being in the Euro market you likely have more choices for LED replacements than we do in the US.

The typical cheap LED H4 replacement bulb advertising a gazillion Chinese lumens are very poorly focused in housings originally designed for an incandescent filament. There are some very good LED replacement bulbs compatible with motorcycle housings  but they are pricey, in the 75 to $100 range each.  Also note that they have a fan mounted on the rear that may not clear the inside of the headlight shell.

 

slmjim 

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rmwesley
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slmjim wrote:

What bike?

slmjim 

Many thanks for the reply, however they are the type of bikes which you need to pedal yourself laughing

slmjim
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rmwesley wrote:

slmjim wrote:

What bike?

slmjim 

Many thanks for the reply, however they are the type of bikes which you need to pedal yourself laughing

When a lifelong motorcycle enthusiast sees "bike", first thought is 'motorcycle'.

Good luck with your project!

 

slmjim

Smile! It makes others wonder what you've been up to.

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Vegas LED Fan
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It’s pretty easy to find bayonet type PR2 conversion bulbs intended as a direct drop in for flashlights. These can be obtained in either a bulb designed for a single voltage (4.5 or 6V) or designed to handle voltages over a range from 6 to 24V DC in a single bulb. Example: https://www.ebay.com/itm/194964526706

More likely you have a screw base in an older headlight so one like this would be a solution and the price is cheap enough to throw it away if it doesn’t work out. Examples either:
https://www.ebay.com/itm/224586031483 or https://www.ebay.com/itm/224586031483

My preference would be to choose a multi-voltage bulb and power it with one of the Li-ion battery packs specifically designed for bike lights. The output is 8.4V, uses four 18650 batteries, and is relatively inexpensive. Example: https://www.ebay.com/itm/144741418790 Look for one that ships from China or the UK for faster delivery. If from China, buy from one that ships using SpeedPAK for a reasonable shipping time.

The output for a SMD 2835 LED like the one listed by Argo is pretty wussy for a bike light. It varies with the LED color but the range listed for SMD 2835 is 20 to 35 lumens per chip and that bulb only has one chip.

rmwesley
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Vegas LED Fan wrote:
It's pretty easy to find bayonet type PR2 conversion bulbs intended as a direct drop in for flashlights. These can be obtained in either a bulb designed for a single voltage (4.5 or 6V) or designed to handle voltages over a range from 6 to 24V DC in a single bulb. Example: https://www.ebay.com/itm/194964526706 More likely you have a screw base in an older headlight so one like this would be a solution and the price is cheap enough to throw it away if it doesn't work out. Examples either: https://www.ebay.com/itm/224586031483 or https://www.ebay.com/itm/224586031483 My preference would be to choose a multi-voltage bulb and power it with one of the Li-ion battery packs specifically designed for bike lights. The output is 8.4V, uses four 18650 batteries, and is relatively inexpensive. Example: https://www.ebay.com/itm/144741418790 Look for one that ships from China or the UK for faster delivery. If from China, buy from one that ships using SpeedPAK for a reasonable shipping time. The output for a SMD 2835 LED like the one listed by Argo is pretty wussy for a bike light. It varies with the LED color but the range listed for SMD 2835 is 20 to 35 lumens per chip and that bulb only has one chip.

Great advice, many thanks. Like you say, the items you've linked to don't cost mega-bucks so I might just buy a few samples and see how I get on.

rmwesley
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In the absence of having anything better to share pics of at the moment, here is a small taillight which might suit a small self-contained LED and battery. Previously this would have been powered by a dynamo hub with the cable entering the unit via the small hole seen in one of the pics. Don't worry about the state of the light laughing It just needs a clean and some Autosol and it will look like new. I'm also still figuring how to upload pics... bear with me. I've seen the "how to" post, just can't get it to work at the moment.

I guess the on / off switch might be the biggest issue since you wouldn’t want to have to unscrew it and take it apart each time you want to use it.

Pic #1

Pic #2

Pic #3

Pic #4

Pic #5

smurcod
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You could probably buy a modern LED rear light and fit the whole thing inside that one. Big Smile Mount a momentary contact switch in the cable hole to turn it on/ off.

I recall using the old dynamo lights- they were next to useless when moving and dangerous if you stopped!

neo71665
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Personally I wouldn’t mod anything vintage short of a drop in LED bulb. All the reasons already posted. I would just restore it for the look and get a modern light for actual use.