The Full Beam Fusion SpeedLED is the brightest light we've had on test with a staggering 3000 lumen output, but it’s the speed sensing technology that makes the SpeedLED such an outstanding product. It sure doesn’t come cheap though.

The faster you ride the brighter it shines is the very simple concept with Full Beam’s SpeedLED. Unlike the Exposure Reflex which uses accelerometers, the SpeedLED uses a rather simpler sensor fixed to the forks and reads your speed from a spoke mounted magnet. Much like a wired cycle computer.

Setting up the light is easy, and while fixing the cable to the forks and routing it carefully is a little fiddly, it is at least straightforward. Full Beam recognise that some people don’t want to trail a cable from their handlebars to the fork, and will be releasing a wireless version next year. It will be retrofittable to current lights too which is good news if you’ve just bought one.

Full Beam Fusion SpeedLED packs an impressive punch

Up and running and out on the trails, the SpeedLED, programmed to the speed sensing mode (you can go fully manual if you prefer), works very well indeed. Start in the dim setting and as you begin piling on the speed so the light automatically gets brighter. This means that on the climbs the light dims to a lower setting, and as the trail flattens and you pick up speed the brightness ramps up.

The light ramps up with noticeable steps. It’s not quite as smooth as the Reflex but after a short while you don’t really notice. It’s fully programmable, you can adjust the power levels, the max speed required to get the brightest setting and the dimming rate. And you can opt for a manual mode if you prefer.

Three Cree XM-L LEDs combine to deliver 3000 lumens of output

With this amount of light it really is a case of turning night into day. Three Cree XM-L LEDs are arranged in the sleek machined aluminium housing with slim cooling fins along the sides. The beam they project is vast and blankets every inch and fold of the trail with a clear and consistent spread of illumination. Reach is fantastic making high speed runs a joy and lower speed climbing sees the beam offering good spread to the sides. It’s sufficiently bright that we had no hesitation in holding back with this light, and could happily hit familiar trails at regular daylight speeds.


We got very good run times with our test light. Because the light is running at variable brightnesses, the light can often run cooler as they don’t get a chance to heat up too much, placing less strain on the batteries. We did a couple of typical 2-3 hour night rides and the light was still going well, so the claimed 4-5 hours be Full Beam is about right.

Any scepticism about a light that automatically adjusts the brightness based on ride speed we had before the test was quickly banished after just one ride. We’re very impressed, and can’t wait for the technology to trickle down to more affordable lights.

Full Beam Fusion SpeedLED packs an impressive punch

The SpeedLED fixes to the handlebars with a rather crude but effective quick release clamp. We experienced no bounce of the light over roots or rocks, and it’s easy to remove or attach quickly.


An impressive technological development the SpeedLED really does work very well. But it’s more expensive than the Reflex and isn’t quite as polished as Exposure Lights offering. If you want the brightest and aren’t put off by the £500 price tag, the SpeedLED is an incredible light.


Fantastically bright

Speed sensing brightness

Battery life



More information: Full Beam

Price: £499.99

What Full Beam say:

Fusion with SpeedLED uses innovation to increase range and brightness beyond anything achievable by lights of a similar size and weight. Look in our Tech section to find out more about SpeedLED. Fusion with SpeedLED produces over 3000 Lumens of light, weighs less than 400g and is powered by a battery integrated into the main lamp unit. Despite its compact size and lightweight it has typical run-times of 4-5 hours.

  • 3000 Lumens light output from 3 High Efficacy LEDs throws light a long way down the trail
  • Under 400g total system weight
  • Typical run-times of 4-5 hours
  • Intelligent LED and battery protection
  • Quick 2 hours charge time
  • Low battery warning
  • Single bar mounting lamp unit
  • Very rugged and Weatherproof