Cycle Light Review
Modern bike lights can be split into two main categories – lights for road/commuting use and lights for mountain bike use. It's important to be clear what type you're after, as they differ vastly in terms of light output, run time, weight and expense.
Mountain bike lights are largely about power – they need to light up unlit trails in dark woods littered with rocks, roots and other obstacles, generally only for short periods at a time.
Road/commuter lights, on the other hand, are designed primarily to make the cyclist visible to other road users. Factors such as battery life, weight and side visibility are more important than pure power. Prices are a lot lower, too.
Setting the standard
Technically, all bike lights must be fitted to comply with the Road Vehicle Lighting Regulations (RVLR). For the record, here's what those regs say...
One is required, showing a white light, positioned centrally or offside, up to 1500mm from the ground, aligned towards and visible from the front. If capable of emitting a steady light it must be marked as conforming to BS6102/3 or an equivalent EC standard. If capable of emitting only a flashing light, it must emit at least 4 candela.
One is required, to show a red light, positioned centrally or offside, between 350mm and 1500mm from the ground, at or near the rear, aligned towards and visible from behind. If capable of emitting a steady light it must be marked as conforming to BS3648, or BS6102/3, or an equivalent EC standard. If capable of emitting only a flashing light, it must emit at least 4 candela.
You also need a rear reflector and four pedal reflectors to fully comply with the RVLR.
In practice, not all bike lights are kitemarked. The specification for lights dates back to 1986 and is designed to apply to lights with filament bulbs. That doesn't mean that LED lights can't meet the requirements – some do – but lots of them aren't specifically tested for the ageing Brititsh standard, especially those that are for the worldwide market. Since the RVLR was amended to allow cyclists to fit flashing LEDs we've heard very little about cyclists being stopped for having non-compliant lights.
Choosing a light: things to consider
What am I going to use the light for?
Are you going to be pootling down to the shops, or do you detour through the woods on the way home? You need to consider how much light you need, and where you need it to be put. Brighter is generally better, but look for lights with good side visibility if you're riding a lot in town. On-road lights tend to have a narrower beam, off-road units a wider spread.
If you're going to be doing a lot of swapping between bikes, consider how easy that's going to be. Are the mounts quick release? Are there lots of wires to deal with?
How regularly will I use the light, and how long per day?
If your commute is an hour and your light gives out after 50 minutes then you're in trouble. If it has a proprietary charger rather than batteries or a USB charge option, then it needs to last to where you're going and back again. Think about when you'll recharge the light and how long that will take.
Many lights have low-power options that will extend battery life, so it's important to work out if these will give you enough output for certain sections of your ride. Many lights have fuel gauge displays to let you know the state of the battery, these can be very useful if you ride regularly and aren't good at remembering to charge your lights.
What conditions will I use the light in?
If you're riding every day, come what may, your lights will take a beating. They're very exposed to rain and spray at the front of your bike. Generally the more expensive lights are better constructed with more effective seals, so spend as much as you can afford. If you think you might break your lights from using them in all conditions, check what the warranty is like.
Okay, so you've got to buy some lights. What kind of lights do you need? here's a quick run down of the basic types you can get your hands on, and who they're aimed at.
small enough to leave in your bag for when you need them, emergency lights normally attach with a stretchy band to the bars or frame and are powered by button cells. They don't put out a great deal of light but as an get-you-home solution if you get caught out or your main lights fail, they're a lot better than nothing.
The next step up is a bar/frame-mounted flasher. Most of these are capable of putting out a steady beam too. They're a bit bigger and sturdier than an emergency light, and they generally take AAA batteries which last for ages. You can pick them up cheap so they can be better value all round – in terms of buying and running – than emergency lights. Nearly all rear lights fall into this category.
There's lots and lots of choice when it comes to torch-style front lights. Powered either by AA/AAA cells or a rechargeable battery pack, they tend to put out a bit more light: if your riding takes you anywhere you need to see – rather than just be seen – you'll need at least one of these. Often manufacturers will bundle a torch-style front light with a rear flasher, seeing to both ends of your bike and scoring you a bit of a discount in the process. Rechargeable units often come with a mains adaptor but USB chargers are becoming increasingly common, allowing you to juice up your light at your desk.
These tend to be characterised by a separate battery pack attached to a smaller head unit that's a lot more powerful than a standard torch. They start at around £50 but you can pay the best part of a grand for the really high end stuff. If you want to go out and train after dark on the lanes, or venture off-road, then a rechargeable set is probably your best bet.
If you want your lights to be a permanent fixture and never worry about batteries then you can't do better than a dynamo. Hub dynamos are the pick for low maintenance and decent output; most will supply 2.4-3W which is plenty for a bright light front and rear. Pick a system that stores some of the energy from the dynamo so you don't go dark when you're stopped at the traffic lights, generally known as a stand light, this will give a couple of minutes for those stationary moments, not all dynamo systems have standlights.
Another way to run a light from dynamo power is to use a USB system like Tout Terrain's Plug and a light that's USB-chargeable; many lights can be charged this way nowadays.
Fitting a light to your helmet means you can point the beam where you want it, making the light a lot more useful. Some of the smaller rechargeable systems come with a helmet mount, or you could go for a more general use headband-type light and ziptie it on.
Common sense is the key to cycle lights, can you see and be seen? Do you have enough power in your lights to last your journey?
Spend what you can afford (but do shop around) take time to go and look at different types of lights.
Personally I always have some of the emergency lights in my pockets, just in case.