Mountain Bike MTB Fair Dinkum 12 Volt LED Headlight...




This is info about a 120mm LED headlightlight I fitted to my MTB in Tasmania Down Under.

The light is removable, so can use it for a boat light, shed or general light when not using it on bike if needed.

Wiring is very basic and lo tech.

Unlike other hi tech hi power lights , all the bits are off the shelf. No circuitry, no heatsinks, no waterproofing needed. No guesses but no reason it won't last years. By then I'll have the spare $18 light to replace it with. Likely you could get a free battery if you know any alarm/ light service people. They regularly replace them as a precaution. Many are AOK.

Step 1: Details About MTB Bike Headlight Install.

I commute and ride my bike at night. Especially in summer cooler time.

The standard small battery bike headlights have a few problems. 1) low output. 2) Hence you get cars on road flashing lights to check out what's in distance ie you. Blinds the rider.3) For high output read high price if you want a bright pushbike light. Saw one other day was about a grand! Had to be a different way to fix problem.

- I had a small 5 amp sealed battery. Not too big. Fits on bike rack About 40 bucks new.

- I bought 2 each 27 watt multi led aluminium case lights from usual ebay .

Two for 35 bucks roughly . Included postage and came with mountings.

Only need some wiring? used old 240v extension cord internal wires. And a basic toggle switch from shed junk.

Plus an inline fuse, though not really needed. Even a short would be low risk..

A luxury add on was a piece of 8mm acrylic sheet bent in a twist with heat gun and vice. Glued to light case, it sends a bright light to my trip computer when light is on.

I have a 12v electronic charger for trickle charging of batteries in my shed. So is easy to recharge eg once a week.

The 120mm light is a size I'm not worried about. Looks not a worry. In fact it looks pretty over the top. Good for safety and it get comments! This is more like a full blown motorbike headlight..

Step 2: Output of Light..

Picture shown is output.

Is a very bright white 27 watt led light. Really looks like a motorbike etc coming towards a driver. The oncoming cars don't see it as a pushie, so don't flash at me! It really lights up compared to standard bike lights.

I ride about 45mins each trip. Get a week's riding when I'm using it . I trickle charge when needed. Light reduces as charge drops, but lasts about 4 trips on full use.I sometimes ride with light off if no one around and good moon/ streetlights.

Step 3: Battery I Use on MTB Rack

The battery is a small sealed 5 amp 12 volt one.I rubber strap it to carrier and have blade terminals that push on and off.

Some comments.. Yes it's heavier than a smaller bike light battery. I'm not mtb heavy duty riding. Bike is med quality but not a hardcore jumps bike.. I'd take it off if rough hi speed riding happens.Though no reason why it would fail.

The optic fibre style auxillary light souce works great, Have a nice light around top of handlebars so can see trip computer. And gear change numbers nearby.

Overall cost is about 80 bucks. Including battery, wires and switch. Plus I bought a lights pair so have 1 total light as spare.

Like most builders I have spare bits eg charger , so not a cost.I can also charge it with my solar camping panel.

This thing saved my life last night. A drink driver almost wiped me out after he smashed a fence to pieces reversing out of a driveway. Was only my light being able to see a 50 to 100 yards ahead that let me see the incident. Could have ridden into a 300lb lump of brickwork that was thrown 20 feet into my path. It's paid for itself.A smaller standard light? Could have a broken leg now..And bike..

This light beats any hi tech bike light as it's cheap, practical and built strongly.. Have dropped bike a few times and it just keeps on going. No heat comes out of light.Sure, some weight with battery but no system's perfect , especially for 100 bucks! The optic fibre makes it different to a basic install. Nothing is hi tech, all within skills of average DIYers Optic fibre light isn't that hard to do..



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    5 Discussions


    2 years ago

    PS fair dinkum is Aussie speak for True..

    eg "Fair dinkum mate" ....I'm as parched as a dead dingo's donger"


    2 years ago

    Added another optic fibre light to gear shifters on sides.. To show gear numbers at nightThis time did it easier. Used old clear hex shape winder rods from small venetion blinds. From tip shop.. About 3 feet long and already good size to transfer light. Bend with heat gun. Polish on wet and dry fror nice clear ends.Glued across light front at bottom to pick up light. I used cartrdige brown "Builders glue". Cheap. The stuff you glue sheet products to wall studs with in eg caravans, bathrooms.Non agressive on the acrylic rod. Now I have trip computer plus both left and right gear shifts lit up at night with headlight on. $5000 bikes don't have that!


    2 years ago

    Dinkum? Cool! I assume that's a reference to The Moon is a Harsh Mistress? Nice 'able too.

    2 replies

    Reply 2 years ago

    Fair Dinkum is what all Aussies learnt to say in general conversation.
    Those born since about 1970 don't use it. Too Aussie for them..