Lighting

Lighting for your motorcycle

Lighting on a motorcycle has two jobs: letting you see the road, and letting others see you. This collection covers headlights, taillights, brake lights, turn signals, licence plate lights, marker lights and the wiring and brackets that make it all work.

On a bike the lit area is small compared to a car, and you only have one headlight to ride by. That makes light output, beam pattern and positioning matter far more than they do on four wheels.

Choosing between halogen and LED isn't only about brightness. It's about current draw, heat dissipation, flash rate, approval and whether the part even fits the headlight shell or bracket you have.

This guide runs through dimensions and markings, the differences between light sources, what suits your riding, how to spot wear, and what to watch out for during fitting.

We stock lighting from MCS, Custom Dynamics, Namz, Zodiac, Drag Specialties, K&S Technologies, Kellermann, Heinz Bikes, Denali, Moose Offroad, Ciro 3D, Ciro, Kuryakyn, V-Twin and Cult-Werk.

The collection holds over 7,700 part numbers with the vast majority in stock for fast dispatch, and there's free shipping on orders over €200 at Partsdenmark.com.

Dimensions, markings and construction you need to know

Before you order, you need to know three things: the light's diameter or housing dimensions, the bulb base or LED module type, and which approval the part carries. Get one of those three wrong and the part won't go on.

Motorcycle headlights typically come in round standard sizes, while modern models often have integrated housings that can only be replaced with a dedicated unit.

Typical sizes and bases

• Round headlights in 4½", 5¾" and 7" are the most common on custom and cruiser builds
• Halogen bases such as H4 (dipped and main beam in one bulb) and H7 or H11 for separate functions
• Bayonet bases with one or two filaments for tail and brake lights
• Turn signals with a 3-bolt pattern or a single through-hole threaded stud
• Base dimensions and bolt hole spacing on Mount and Handlebar type brackets

Markings and approval

• An E-mark in the lens or housing is a prerequisite for legal use on public roads
• Turn signals must be amber, taillights red and licence plate lights white
• Work and auxiliary lights without approval are intended for closed course or off-road use
• Colour temperature is given in kelvin: halogen sits around 3,200 K, white LED typically 5,000-6,000 K
• The system runs 12 volts, and polarity must be respected on LED modules

If you're unsure what fits, use the Find your bike function on Partsdenmark.com. That filters the range down to the parts listed for your exact year and model.

Choose lighting to suit your riding

The right lighting depends on where and when you ride. A city commuter needs to be seen, while a touring rider in the dark needs to see far ahead.

Riding style	Type	Advantages	Drawbacks	Brands in the range
City riding and commuting	LED turn signals and running lights	High visibility, low current draw, fast response time	Often requires a relay or resistor	Kellermann, Heinz Bikes, K&S Technologies
Open road and touring	LED headlight with main beam	Long beam throw, stable light colour, long service life	Higher price than halogen	Custom Dynamics, MCS, Zodiac
Custom and cruiser	Accent lights, marker lights and light visors	Sets the look, plenty of finish options	Limited gains in actual light output	Ciro 3D, Ciro, Kuryakyn, Cult-Werk
Off-road and adventure	Auxiliary lights and flood lights	Wide coverage up close, rugged construction	Dazzles oncoming traffic if used wrongly	Denali, Moose Offroad, Drag Specialties
Custom builds and repair	Wiring kits, connectors and brackets	Clean installation without cutting into the original loom	Requires a grasp of the wiring diagram	Namz, MCS, V-Twin

If you ride mostly in daylight and in town, you get the most out of upgrading turn signals and brake light first. It's the cheapest place to start, and it's where car drivers overlook you.

If you ride a lot in the dark on open roads, the headlight is the investment that makes the biggest difference. A modern LED unit with a sharp cut-off puts more light on the tarmac and dazzles oncoming traffic less than a worn halogen reflector.

Light sources and variants explained

There are really three routes: keep halogen, swap the bulb for an LED replacement, or replace the entire light unit. The three solutions give very different results.

Halogen

Halogen is the original solution on most older machines. It's reliable, cheap to replace, and the beam pattern is predictable because the reflector is designed around that specific filament.

On the other hand, halogen draws more current, gives a yellowish light and has a service life typically measured in a few hundred hours. With Replacement bulbs and Light units, it's often the simplest route back to full function.

LED modules and complete units

A complete LED unit is designed around the light source from the outset, which is why the cut-off is sharp and the output high. Series such as ProBeam from Custom Dynamics cover Headlight, Taillight and Turn Signals alike.

LED draws considerably less current than halogen for the same amount of light, which is an advantage on machines with a modest alternator. The heat is moved rearwards in the housing at the same time, so cooling fins or heat sinks need free air.

Turn signals, marker lights and licence plate lights

Turn signals come as Handlebar Turn Signals, as stalk-mounted Turn Signal units and as built-in modules. Amber and Amber Lens describe the yellow colour required for a legal indicator.

For the rear end there are License Plate holders with a built-in light and Marker Lights for the sides and rear mudguard. They take up a bit of space, but they make the outline of the bike clear to traffic coming from the side.

Wear, service life and maintenance

Lighting rarely fails without warning. Dim light, misting inside the lens and irregular flashing are signs that show up a while before the actual failure.

Bulbs and light output

A halogen bulb gradually gets weaker, and the glass darkens on the inside as the filament evaporates. If you see a grey or brownish deposit inside the bulb, it's close to the end.

Always change both bulbs in a twin setup at the same time so the light colour matches. Don't touch halogen glass with your fingers — grease from your skin causes local overheating and early failure.

LEDs don't blacken, but they lose output over time and can shift colour towards the blue. If the light drops noticeably, or individual diodes flicker, the module is on its way out.

Reflector, lens and sealing

Condensation in the headlight housing is the clearest sign that a seal or vent is faulty. Water destroys the reflector coating, and a hazed reflector layer can't be polished back.

Crazed or stone-chipped glass scatters the light uncontrollably and causes dazzle. Also check that Amber Lens lenses on turn signals haven't faded, because a pale lens cuts visibility significantly.

Wiring, connectors and earth

The vast majority of lighting faults on older machines are in the earth and connectors, not the bulb. Green corrosion in a Connector plug or a loose earth point under the tank gives weak light and random dropouts.

Check the connectors at least once a year, and use contact grease on the connections that sit exposed. Namz offers ready-made wiring kits and connectors, so you avoid splicing into the original loom.

Fitting and choosing in practice

Most lighting upgrades can be done at home with ordinary hand tools, but two things need thought: the current draw and the headlight aim.

If you switch to LED turn signals, the current draw drops so much that the original thermal flasher relay either flashes far too fast or not at all. The solution is either an electronic relay or load resistors, available from MCS and Drag Specialties among others.

The flash rate should sit within the normal range of around 60 to 120 flashes per minute. If it flashes faster, that's signalling a fault — and it isn't legal.

When changing a headlight, the cut-off needs setting afterwards. Park the bike square on to a wall a few metres away with yourself sitting on it, and adjust so the horizontal cut-off sits just below the centre height of the light.

Auxiliary lights from Denali and Moose Offroad are fitted with their own relay and fuse straight off the battery. Route the cables clear of the steering's range of movement, and leave a loop so the wire doesn't pull tight at full lock.

Finally, check every function: dipped beam, main beam, position light, brake light, both indicator directions and the licence plate light. It takes two minutes and catches the faults that would otherwise only show up in the dark.

Frequently asked questions about lighting

Here are the questions we get most often about motorcycle lighting, answered briefly and concretely.

Can I fit LED bulbs in a halogen headlight?

Technically it can be done, but the reflector is designed for a filament in a specific position, so the beam pattern often ends up diffuse with a poor cut-off. For road use, a complete, approved LED unit is the right solution.

For main beam alone the cut-off requirement is less strict, so a bulb swap is less of a problem there. The dipped beam is the critical one.

Why does my indicator flash too fast after switching to LED?

The original relay measures current draw to detect a blown bulb. LEDs draw too little current, and the relay reads it as a fault.

Fit an electronic flasher relay or load resistors at each LED turn signal and the problem is solved. Both are in the collection.

Do turn signals have to be amber?

Yes. Turn signals must be amber both front and rear, whether the lens is clear or coloured. A clear lens is legal as long as the light itself is amber — which is why both Amber modules and Amber Lens lenses are in the range.

Can I use turn signals as position lights or brake lights?

Several modules from Custom Dynamics, Kellermann and Heinz Bikes can run as combined running light and turn signal, where the white function switches off while the amber flashes. That takes an extra wire and in some cases a small control module.

There are equivalent solutions for the rear, where red light and amber flash share the same housing. Always check that the specific variant is listed as E-marked for road use.

How much light do I need on open roads in the dark?

For ordinary open-road riding, a properly working, correctly aimed headlight matters more than extra watts. If the dipped beam has a sharp cut-off and reaches far enough for your speed, there's rarely any need for more.

If you regularly ride unlit roads or terrain with a lot of wildlife, a pair of auxiliary lights makes a real difference in width. They must be switchable independently so you don't dazzle oncoming traffic.

If you want to go further into the detail, you'll find the individual categories under headlights, tail and brake lights and turn signals. Use Find your bike first, so you only see the parts that fit your machine.

All items at Partsdenmark.com are covered by 2-year right of complaint, and we offer a European price match if you find the same item cheaper at a European dealer. If you have questions about fitment or wiring, you're welcome to contact us before you order.