The RSP Steradian gets its name from the Greek for ‘solid beam’. It uses a single-watt LED that seems a lot brighter thanks to clever collimator lens technology, which is traditionally used to guide lasers. You get a very crisp, solid beam that’s good enough in high power mode for shorter journeys in pitch darkness.
Raleigh say the Steradian pumps out an impressive 1200 candlepower, three times that of some other single watt lights. There are three lighting modes: high, low, and flashing. The highest setting provides a spotlight with pin-sharp focus, giving sufficient light to see properly on unlit, rural lanes at 16mph. An integrated cowling prevents the light from shining upwards and dazzling.
It’ll last 19 hours on high power, compared to 26 in low and 33 in flashing, and you can eke out the run time by switching between modes as necessary. Flashing is particularly effective for being seen by in twilight conditions and when tackling urban traffic systems with roundabouts and side roads. Last season’s RSP range suffered from poor peripheral visibility. This has been greatly improved for 2010/11; from the graph you can see that although it's not as bright in the centre as some competing lights, it has a good peripheral spread.
The weather sealing and build quality are as good as lights costing twice as much, and the Steradian’s dense plastic casing should take road vibration and casual commuter carelessness in its stride. The sensible positioning of the switch should prevent the light flicking on at the bottom of a bag. It’s easy to turn it on or off or toggle between modes while riding, however, and the switch has a positive feel when pressed.
Popping open the casing reveals the sealed lens and the battery tray for its four AAAs. This sealing is effective, giving the Steradian impressive weather resistance. Mine has shrugged off prolonged downpours. Even a five-minute onslaught from the garden hose couldn’t reveal any weaknesses. The tool-free bracket fits securely on most handlebar diameters, and stays firm even on rougher roads, bridleways and towpaths.
The Steradian could be all the light you need for commuting and suburban winter training, particular if you’re only making shorter journeys. The latest generation of rechargeable systems still have the edge in convenience and long-term economy.
Impressive budget light for sub/urban commuting and winter training
road.cc test report
Make and model: RSP Steradian LED front light
Size tested: n/a
Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
'RSP Steradian 1 watt front light. Integrated collimator lens technology for optimum efficiency and output.' Essentially it's a very competent commuter light.
Tell us some more about the technical aspects of the product?
Latest collimator technology provides superior optical efficiency, increasing lumen output.
output and better light distribution. This results in a 1 watt LED generating 1200
candle power output.
Better than some costing nearly twice the price.
Very well sealed from the elements.
Very good, given the level of performance.
Tell us how the product performed overall when used for its designed purpose
The Steradian is a remarkably capable lamp that offers excellent illumination in most contexts. Weather seals are better than I had any right to expect and should resist pretty much anything the elements dish out. Perfect for round town and the suburbs, there's sufficient to see by along the lanes in the highest setting but budget high power rechargeable NiCad/NiMh types have the edge for regular rural duties.
Tell us what you particularly liked about the product
Excellent output, reasonable run times, sensible, solid build quality.
Tell us what you particularly disliked about the product
Nothing of note.
Did you enjoy using the product? Yes
Would you consider buying the product? Possibly
Would you recommend the product to a friend? Generally, yes.
About the tester
I usually ride: Rough Stuff Tourer Based around 4130 Univega mtb Frameset My best bike is: 1955 Holdsworth Road Path and several others including cross & traditional road
I've been riding for: Over 20 years I ride: Most days I would class myself as: Experienced
I regularly do the following types of riding: cyclo cross, commuting, touring, fixed/singlespeed, mtb,