Before you start thinking about shopping for bike lights, make sure both you and your bike are visible. If you ride purely under the street lights of an urban environment then it’s likely you’ll just need front and rear lights that will make you visible to other road users.
A more demanding rider will need high-output lighting systems. These are usually rechargeable lighting systems that offer maximum illumination. The most powerful lights are often characterized by a separate battery pack attached to a smaller head unit, that’s a lot more powerful than a standard torch. They are higher priced but much brighter than safety lights, and they help you see where you’re going on the trail or road in nearly all conditions.
In such cases, the intention is to get as much power as possible. If you’re more into mixed-trail riding, you need good lights all the time, and the battery life gets more important. The output of the lights is measured in lumens. A lumen is a unit that quantifies the amount of light falling on the object you want illuminated. Good to know: You may have a 1500-lumen light, but if the battery enables you to run it only at 50% power during a fast cross-country/trail ride, it’s less bright than a ‘weaker’ 1000-lumen unit where you can use 100 percent. Keep in mind that a too powerful light can be a disadvantage sometimes – particularly in wet or foggy conditions, where bounce-back and glare mean you see less than with a less powerful unit. It’s similar to driving a car in fog.
Handlebars or helmet?
Most lights come with both bars and helmet mounting options. Which is better comes down to personal preference, but both kinds have its pros and cons. Helmet light shines where you’re looking, but it flattens out visible trail features and can be knocked off by low trees. If you have a light mounted on the handlebars it’s easy to see indicators and operate switches. A less practical part is that the light only goes where your bars are pointed. In reality the best solution is to use helmet- and bar-mounted lights, even if you have to buy lower powered units to afford both. It also means you have a backup should one battery die. Before spending your money always double-check if the light fits your bars or your helmet.
Mountain bikers should also consider whether they want a narrow beam for straight and fast riding or helmet use, a wider beam for slower, more technical terrain, or a combination of both – which is likely to be more expensive.
Most of the lights use rechargeable systems featuring lithium-ion batteries. They can be charged hundreds of times, making them an inexpensive and environmentally sound alternative to disposable batteries. Unlike alkalines that dim slowly during battery life, most rechargeables deliver consistent light until their power is exhausted. A few years ago, you had a variety of different bulb options to consider, but LED lights have improved and come down in price so there really isn’t a choice any more.