Setting Your Bike Up Right For Riding at Night: Old Man Mountain Lighting Guide

Option 1: Dynamo Generator Lights

A dynamo light is powered by a small generator (called a dynamo) located within the front wheel’s hub, meaning it generates electricity as you pedal, eliminating the need for batteries and ensuring your lights are always on while you ride. Most dynamo lights have a "stand light" feature that keeps them illuminated for a short time after you stop pedaling, and modern dynamo lights can be very bright and provide a wide, consistent beam pattern for good road visibility. They offer several advantages over battery-powered lights but also come with their own set of challenges. Let’s break down the key points to consider:

• Continuous Power: A dynamo provides a constant source of power as long as you are moving. This means you don’t have to worry about batteries running out, especially on longer rides or expeditions. It’s a good choice for long-term use where changing or recharging batteries might be inconvenient or impossible.
• Sustainability: A dynamo generates power while riding, which makes it more eco-friendly than using disposable or rechargeable batteries that need to be replaced or recharged regularly.
• Lower Maintenance Costs: Over time, dynamo systems may be cheaper to maintain than continually purchasing and replacing batteries.

Son 28 Dynamo front hub. On the left you can see the wires that connect lights to the dynamo hub.

Other pros: Dynamos can charge more than your lights!

Yes, a dynamo can charge more than just the lights, but this depends on the type of dynamo and the setup.

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  Traditional Dynamos: These typically provide enough power to run lights (front and rear), but not much more unless you have a high-output dynamo. Traditional dynamos usually provide around 3 watts at 6V.

   

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  High-Output Dynamos: Some high-output dynamos, such as those from brands like Shimano or SON (Schmidt), can charge other devices like GPS units, smartphones, or even power banks while running your lights. They typically provide around 6 watts at 15V.

   

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  Integrated Systems: Some systems include a USB output that allows you to charge electronic devices while still powering lights. However, the power available is usually limited, and it can only charge small devices or offer slow charging. The output is based on speed, so if you're riding along at 15mph and it's putting out 0.5 amps, it would take 4 hours to recharge your iPhone. But if you are cruising down a long descent at 30mph, your phone could charge in 2 hours. The key point is that the faster you ride, the more power you generate, which could charge devices more quickly.

   

Downsides of Dynamos

• Power Output: The power output from a dynamo is directly tied to your speed. At low speeds (e.g., during a slow climb), the dynamo may not generate enough power to run lights at full brightness. In these cases, the lights may dim or flicker.
• Drag: A dynamo generates power by creating resistance, which can make pedaling feel a bit harder. While high-quality dynamos have minimal drag, it's still noticeable, especially on longer rides. According to SON Hub, the dynamo’s nominal values are 6 volts and 3 watts. They are achieved at moderate speeds depending on wheel size and generator type. The real values depend on the electrical load to a large extent indeed. Running with no electrical load results in remarkably higher voltage. At high speeds and with a suitable electrical load, you may use significantly more power.
• Weight and Complexity: Dynamo hubs (the most common type) add weight to your bike, and the system can be more complex to install, particularly if you have to wire up charging components or extra devices.
• Cost: Dynamo hubs, lights, and other components can be expensive, exceptionally high-quality setups like those from SON, Shimano, or Busch & Müller.
• Reliability: While dynamos are quite durable, they can wear out over time, especially if used in tough weather conditions or on rough terrain. Hubs are generally very reliable, but external generators (like bottle dynamos) can be prone to wear.

Key Considerations When Picking a Dynamo:

• Power Output: Make sure the dynamo provides enough power for your needs. Standard dynamos typically output around 3W, which is enough for essential lights. High-output dynamos can provide up to 6W or more, which is suitable for charging devices.
• Compatibility: Ensure the dynamo system is compatible with your bike. Different types of hubs (e.g., front-wheel hubs or bottom-bracket-mounted dynamos) are available, and you need to make sure the hub fits your bike's design.
• Efficiency: Look for a high-efficiency dynamo. High-quality dynamos like those from SON or Shimano are known for low drag, meaning you’ll feel less resistance while riding. Lower-quality or older dynamos may add significant drag, making your ride harder.
• Weather Resistance: Make sure the system is well-sealed and weatherproof if you use it in harsh conditions.
• Installation: If you’re not comfortable installing a dynamo yourself, consider how easy it will be to set up. Some systems may require special hubs, wiring, and installation on your bike.

Brightness of Dynamo Lights

The brightness of dynamo-powered lights varies, but in general:

• • Basic Dynamo Lights: These may offer anywhere from 20 to 80 lux, suitable for city riding or commuting.
  • High-End Dynamo Lights: Some top-tier systems can output up to 150 lux or more, providing a much brighter beam suitable for road cycling, touring, or mountain biking.

In terms of lumens, typical dynamo lights range from 100 to 1300 lumens, but brighter options are available in high-end systems.

Lens/Beam Design

Dynamo lights generally use high-quality lenses and reflector systems to shape and direct the beam. The design of the lens and reflector can vary by brand and light model, but generally:

• • Wide Beams: Many dynamo lights are designed for road use, offering a wide beam with a smooth cut-off to prevent blinding oncoming traffic. These lights are meant to light up the road ahead without being too intense.
  • Focused Beams: Some high-output dynamo lights for off-road or mountain biking may feature more focused beams to extend reach and illumination at higher speeds.

Many modern dynamo lights, especially from brands like Klite, Sinewave, Busch & Müller, or Schmidt, use optics that combine wide flood and long-throw capabilities, ensuring good visibility in all directions, including when turning corners.

Can You Use Dynamos with Suspension?

Yes, you can use dynamo-powered lights with suspension, but there are a few things to consider:

• Cable Routing: With the suspension, you’ll need to ensure the dynamo wiring can flex without getting pinched or damaged. Some systems may have special cables built to withstand the suspension's constant movement.

A dynamo system is a great option for cyclists who need a reliable, long-term power source for lighting and charging devices. They are particularly popular among touring cyclists, commuters, and bikepackers who need lights that won’t fail after a long ride. However, they do come with trade-offs in terms of cost, complexity, and performance at low speeds. When picking a dynamo system, consider factors like power output, efficiency, compatibility with your bike, and whether you plan to use the system for additional devices or just lighting.

Option 2: Rechargeable Battery Lights

Thanks to their convenience, versatility, and performance, rechargeable battery lights have become the go-to choice for many cyclists. They come in a very wide variety from small, simple lights designed to help you be seen by other riders and cars, to powerful, super bright lights for trail riding at night.

Unlike dynamo lights, which have an unlimited power source while you’re riding, lights with rechargeable batteries have to store all of their energy. This means that for a light to last longer, it will need a bigger battery. Those bigger batteries will take longer to charge, so if you are on a long, multi-day trip and riding in the dark for many hours, it may be difficult to recharge.

While a wall outlet can recharge these lights in a few hours, you must ensure access to an outlet on your route or plan accordingly.

Most ultra-racers and long-distance backpackers now carry a power bank. A 10,000-20,000mAh power bank will allow you to recharge your lights, phone, and GPS a few times. You can calculate how big of a power bank you need by looking up the battery capacity of your lights and phone. For example, the Outbound Lighting Detour has a battery capacity of 5000mAh, so I could recharge it twice with a 10,000mAh battery pack.

Pro Tip: If using a power bank, secure it in a frame bag and run a USB cable to your light to charge it while riding!

Dynamo Hub System (Hybrid Charging) 

While we focused on dynamo lights above you could also choose to use a battery powered light and use the dynamo to recharge that light or your other devices. Klite, Sinwave, and Cinq all offer USB plug adapters to convert the dynamo power from your hub into a USB output.

This is useful for touring cyclists who ride long distances and don’t always have access to electrical outlets. This versatility means you never have to worry about running out of batteries as long as you have access to a power source—something that wasn’t possible with older, disposable battery-powered lights.

Lightweight Design

Compared to dynamo-powered lights or bulky battery packs, USB-rechargeable lights are much lighter and more compact, making them ideal for cyclists prioritizing weight savings.

Multiple Brightness Levels and Flashing Modes

One of the standout features of rechargeable bike lights is their ability to adjust brightness and beam patterns depending on riding conditions. They are also very useful during the day for busy roads, foggy days, or situations where continuous lighting is not required, but it’s just as important to be seen.

An advantage of adjustable brightness is that you can conserve battery life with lower settings. Modern lights allow you to switch between multiple brightness levels (e.g., Low, Medium, High, Boost).

For example, The Light & Motion Urban 1000 has four modes:

• High (1000 lumens, 1.5-hour run time)
• Medium (500 lumens, 3-hour run time)
• Low (250 lumens, 6-hour run time)
• Pulse Mode (daytime visibility, 12-hour run time)

Pro Tip: Using a lower setting when riding in well-lit areas extends battery life significantly.

Increase Visibility in Traffic with Flashing Modes and Leg Illumination

Flashing modes are especially useful for urban riders, as they attract more attention from drivers than a steady beam. However, the type of flashing matters a lot. The Flock Light is a new light that has put a lot of energy into rear light safety. While a simple on-and-off can grab more attention than light just on, it can be hard to gauge distance when it goes off. Flock, Knog, and others have instead introduced pulsing lights that fluctuate in brightness but do not go off.

Flock has added another great new feature which is to make the light shine on your legs and the ground as well as back at cars. This makes the illuminated area far more visible and easier to avoid.

Cons of Rechargeable Battery Lights

The biggest drawback of rechargeable bike lights is their finite battery life. Unlike dynamo-powered lights that generate power continuously, rechargeable lights can only last as long as their battery allows.

• High-power modes (1,000+ lumens) may only last 1-2 hours before needing a recharge.
• Lower brightness settings can extend the run time to several hours but at the cost of reduced visibility.
• Frequent recharging is necessary, especially for riders who rely on maximum brightness.

If a rechargeable bike light dies mid-ride, there’s no immediate backup unless you:

• Carry a power bank and charge while riding.
• Have a spare light (which adds extra weight).
• Use a hub dynamo light as a secondary backup.

Battery anxiety can be a real concern for commuters and long-distance cyclists, especially in winter when daylight hours are shorter.

Option 3: Swappable Battery Lights

Swappable battery lights are still the preferred option in some situations. Unlike USB-rechargeable lights, these lights run on replaceable batteries—standard AA, AAA, CR123 cells, or proprietary lithium-ion battery packs. While they may not be as common today as rechargeable lights, they offer distinct advantages in certain scenarios, such as long-distance touring and emergency preparedness.

Unlike USB-rechargeable lights, which require stopping to recharge the battery, which can take many hours, swappable battery lights let you continue riding indefinitely—as long as you have enough spare batteries.

Pros of Swappable Battery Lights

1. Extended Runtime for Long Rides. The most significant advantage of swappable battery lights is that you can easily extend their runtime. Instead of waiting for a USB-rechargeable light to recharge for hours, you can swap fresh batteries and keep going. This is especially useful for ultra-distance rides, long tours, and bikepacking adventures where charging options may be limited. The Fenix BC30 V2.0 provides 6 hours of runtime at 1000 lumens on a set of two 18650 batteries.  If you carry two spare batteries, you instantly double your runtime without stopping and recharging.
2. Perfect for Remote Adventures & Bikepacking.  If you’re riding in remote areas without access to electricity, swappable battery lights provide an easy power solution. For example, on a week-long bikepacking trip, a cyclist using a USB-rechargeable light would need a solar panel or large power bank to keep their lights charged. A swappable battery light user could simply carry a pack of AA batteries or extra lithium-ion cells, ensuring a constant power source.  For cyclists traveling in wilderness areas, deserts, or off-grid locations, being able to swap batteries rather than wait for a recharge can be a lifesaver.
3. Instant Power—No Downtime. With rechargeable lights, when the battery runs out, you must stop and wait for it to recharge. With swappable battery lights, you can immediately restore power by inserting fresh batteries.  A commuter whose light dies mid-ride can simply pop in a new set of AA batteries and keep going rather than ride home in the dark or wait at a charging station, and a gravel racer or endurance cyclist can quickly swap lithium-ion battery packs instead of losing valuable time waiting for a recharge.

Cons of Swappable Battery Lights

1. Heavier Than USB-Rechargeable Lights. Swappable battery lights tend to be bulkier and heavier because they require removable battery compartments.  The Fenix BC30 V2.0 (2 x 18650 batteries) weighs 154g without batteries, while the Lezyne Lite Drive 1000XL (USB rechargeable) weighs 153g total, including the built-in battery. AA battery-powered lights are even bulkier because alkaline cells have lower energy density than lithium-ion cells.  For racers, weight-conscious road cyclists, or minimalist bikepackers, the extra weight may not be ideal.
2. Higher Long-Term Cost.  While swappable battery lights offer longer usability, the cost of replacement batteries can add up over time. Alkaline AA batteries cost $0.50 - $1 per battery. If you go through two weekly, that’s $50+ per year just in batteries. Rechargeable 18650 lithium-ion batteries cost $10-$20 each and need to be replaced every 500-1000 charge cycles.
3. Some Models Are Less Bright or Efficient.  Many AA/AAA-powered lights don’t provide the same brightness and efficiency as modern USB-rechargeable models.  The Cateye HL-EL135 (3x LED, AA batteries) only produces 150 lumens, whereas a USB-rechargeable Lezyne Lite Drive 1000XL offers 1000 lumens in a much smaller package. Standard alkaline batteries lose voltage over time, reducing brightness as they drain.

So, which bike light is right for you?

If you’re a commuter, where your rides are shorter, and you have ample access to recharge your lights, a USB-rechargeable light offers convenience and sustainability, ensuring you always have a reliable illumination source.

Bikepacking and touring make it a much more complicated question. First, consider how much you could need to ride at night. I say “could” because plans are great, but you need to be prepared for the what-if scenario. If you don’t intend to ride at night because you plan to arrive and set up camp in the evening, then a rechargeable light is a simple and easy option.

If you have lofty goals to ride long distances each day, no matter how many hours, or if you are taking an extended trip without recharging options, a dynamo hub is an excellent option. Dynamo lights are a great hands-off option for those who want a set-it-and-forget-it solution.

Consider your riding habits, preferences, and typical terrain to choose the best light for your needs. After you choose the ideal lighting for your rides, how do you mount them on your bike? We’ve got you!

How to Light Up Your Bike: Options with Racks and Mounting

Where you place your light can be as important as its brightness, and this can be complicated if you have front racks and bags that could get in the way. Always check where you mount your light before your trip to ensure that you do not block it when you add racks and bags to your bike.

If you run a basket or a bag on the deck of your rack, you might not be able to put your headlight on your handlebars. Using the Old Man Mountain Headlight Mount will put the light in front of your bags, allowing it to illuminate your path unobstructed by gear.

The same can be said of rear racks. Most lights are designed to mount to a seatpost but will quickly be blocked by panniers and racks. Luckily we have a versatile Taillight Mount to put your lights on the back of your rack.

Do you still have any questions or feedback about lighting on an Old Man Mountain Rack? Send a note to our support crew, and we’ll investigate your issue.

How to Mount Lights to Racks

Where you place your light can be as important as its brightness, and this can be complicated if you have front racks and bags that could get in the way. Always check where you mount your light before your trip to ensure that you do not block it when you add racks and bags to your bike.

If you run a basket or a bag on the deck of your rack, you might not be able to put your headlight on your handlebars. Using the Old Man Mountain Headlight Mount will put the light in front of your bags, allowing it to illuminate your path unobstructed by gear.

The same can be said of rear racks. Most lights are designed to mount to a seatpost but will quickly be blocked by panniers and racks. Luckily we have a versatile Taillight Mount to put your lights on the back of your rack.

Do you still have any questions or feedback about lighting on an Old Man Mountain Rack? Send a note to our support crew, and we’ll investigate your issue.