LED Brake light conversion for a 1993 Triumph Tiger (version 1)

I bought a 1993 Triumph Tiger last August to run through Winter.  As it happens, for one reason or another, I didn’t get it on the road until December.  In the three months I ran it, I went through around six stop/tail bulbs of various types, including LED bulbs.  I have no idea why the bulbs kept blowing but I decided that I could resolve this issue by designing my own LED circuit with some over voltage protection built in.

The main reasons for deciding to build my own circuit were as follows:

  • Off-the-shelf LED bulbs are not efficient at putting the light where you want it – and because of this, are often not as bright as filament bulbs.
  • My bike was blowing bulbs quicker than I was able to buy replacements.
  • I wanted to incorporate a flashing brake light circuit
  • I fancied doing something different

The initial design included two 12v regulators and two polarity protective diodes; one for each of the stop and  tail light circuits.


When fitted to the bike, I found that the voltage drop across the regulators and various diodes was too much and the LEDs were not bright enough.  I removed the voltage regulators from the circuit and this solved the problem – thought the LEDs were still not as bright as during testing.  This was my fault as I only had an 18v source when testing.

Videos of the original breadboard test circuit:



I only have pictures of the installed circuit on the bike – no video.  Since installation, whatever was killing the bulbs seems to have affected the brake flasher circuit and, although it still works, it no longer works the way it should.


Update: I replaced a capacitor on the circuit board and it is now working – shame about the rest of the bike 🙂


I am sorry there is no circuit diagram or more in depth detail about the circuitry.  I didn’t keep the circuit diagrams as I was using unregistered software which wouldn’t let me save the diagrams.  I am planning a version 2 of this circuit that will be based on 9v instead of 12v so that voltage drop shouldn’t be a problem (if anyone reads this, can you please recommend a decent circuit diagram package).

6 thoughts on “LED Brake light conversion for a 1993 Triumph Tiger (version 1)”

  1. Hi, my name is wai kit. I’m planning to make a LED tail light for my bike. My bike model is kawasaki eliminator 250. The reason i wan to do this is because LED light are more brighter compare to bulb. Can u give me the circuit diagram on how to do that, so that i can DIY myself!!! Thanks you

    1. Hi Wai, I lost the circuit I designed. The web page for the flashing part of the circuit is no longer available, but I do have a print out of that circuit which I will upload. You may find you will need to tweak some of the components on the bread board before use. I will try and get the diagram uploaded today.

  2. Hi Wai, I managed to restore most of the original page for the flashing part of the circuit. You can find the rescued page here: http://www.axia.org.uk/downloads/rescued/motflash.html
    I will be adding a copy of the circuit when I have scanned it.
    The following link is to the PWM part of the circuit: http://www.reuk.co.uk/LED-Dimmer-Circuit.htm
    I used a 556 timer chip so that I could modulate the tail light brightness and the brake light brightness. There is probably no need to modulate the brake light brightness in most cases, though.
    If I get time, I will try and create a schematic for the circuit I implemented on the bike.

  3. Matt,

    Looks great.

    Did you use the stock brake light bezel (light cover)? Did it blur/muffle the leds?

    I’m doing a sequential turn light setup for my kawasaki concours, just concerned that the light cover will blur the leds and loose the effect of blinking leds.

    1. Hi Colin,

      I used the stock light cover. If I knew how/where to get a replacement cover made, I would have preferred a smoked lens cover. Ideally, for normal operation you would want to use diffused LED’s so as not to create “hot spots”, but if you want a blinking effect, then the none diffused LED’s would be best. These were not diffused but were the damn brightest red LED bulbs I have found to date. Unfortunately, they have also become quite expensive http://www.maplin.co.uk/Module.aspx?ModuleNo=220752 (N26FN).

      Hope this helps to answer your questions.


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