the Lumotec IQ Fly is clearly better than any dynamo-driven light I have ever used. There are two reasons: First, the new LED technology converts the same amount of electrical energy to a larger amount of light. Secondly, the optics have been totally reengineered to produce an evenlyilluminated spot on the ground. According to the manufacturer the light intensity is 40 Lux, measured at a distance of 10 m, and the patch of light is twice as broad as from previous LED headlights. In comparison, halogen lights offer only about 10 Lux. The standlight has also been improved: After stopping it keeps the light as bright as with dynamo power for two seconds. Then it switches to about one third of this brightness. Another very handy feature is the ability to change the angle of tilt of the refl ector. Without tools – even when riding – you can choose three positions (as pictured). You don’t have to fi ddle with the whole light mounting to adjust the beam, which usually just means that it comes loose. This feature is also is very useful so that you can switch to a sort of ‘high beam’ when riding on unlit roads. Why has nobody implemented this simple and practical idea before? The light unit is completely sealed, which makes sense given the tens of thousands of hours of life of the LED. Double wiring is permanently fi xed to the headlight, which removes one more weak point. Although the IQ technology from B&M is also available as a battery headlight, I would recommend using the dynamo-powered one. It is just fantastic to know that all that lighting power comes straight from your legs.
The Fly IQ is available via B&M dealers and distributors worldwide. Manufacturer website: www.bumm.de
SRAM iLight D7
Along with the i-Motion 9 hub gear reviewed elsewhere this issue, SRAM also sent the matching i-Light D7. The combination of the two makes a lot of sense for a town bike: if you want the reliability of hub gears, chances are you’ll also want reliable hub dynamo lighting. The D7 is a higher-end version of SRAM’s D3 dynamo, using a lighter forged outer shell and with, they say, 5% better efficiency thanks to
efficiency thanks to
reduced clearance between internal magnetic
reduced clearance between internal magnetic parts. It’s available in versions with disk brake and i-Brake mounts as well as the plain type we received, and comes with a hollow axle for a quick-release. All versions use sealed deepgroove ball bearings for the axle. It’s a nicely finished product, as I hope the picture shows. Reviewing hub dynamos is a tricky one for me. Without the facilities or inclination to mess around with multimeters and motors to do ‘scientifi c’ testing I’m pretty much reduced to putting it into a wheel and checking it works. As I’m not blessed with ultra-sensitive legs I can’t reliably detect any differences in effi ciency between models – or, for the ones I’ve tried, even whether the dynamo’s switched on or off! Thankfully cleverer heads than mine are on the case. German magazine Aktiv Radfahren (www.radfahren.de) tested the D7 late last
year, comparing it with Shimano’s ‘sports’ dynamo, the 3N80, and against the latest from Schmidt, the SON 20R. This was designed for 20" wheels, but if you’re not too worried about full compliance with German traffic regulations it works fine on larger wheels too. It seems that while the SRAM has a slight weight penalty as compared to the Shimano (565 g vs 484 g, both without quick release), it’s slightly easier-running while switched on, especially at higher speeds. When switched off it’s marginally less efficient than the Shimano. The SON 20R is lighter yet at 390 g and, if combined with an IQ Fly or latest InoLED light (as described opposite), it provides plenty of light (and presumably very low resistance) on 26" or 700c wheels – perhaps the choice for distance rides. A ‘official’ version for larger wheels is expected later this year. The other aspect is of course price: here the I-Light is in the middle, with the Shimano at around € 85 (£55 or so), the D7 at € 110 (around £70) and the SON around € 200 (£130ish). I suspect riders who must have the best will stick with the much more expensive SON, but for the rest of us the differences in weight and performance between any of the modern hub dynamos seem rather marginal. The I-Light does have an advantage over the Shimano in that both disk and drum (i-Brake) mount versions are available, which could make a difference for some. It also, for me at least, looks quite a lot prettier, and I’d probably pay a few extra Euros just for that.
it’s slightly easier-running while switched on, especially at higher speeds. When switched off it’s marginally less efficient than the Shimano. The SON 20R is lighter yet at 390 g and, if combined with an IQ Fly or latest InoLED light (as described opposite), it provides plenty of light (and presumably very low resistance) on 26" or 700c wheels – perhaps the choice for distance rides. A ‘official’ version for larger wheels is expected later this year. The other aspect is of course price: here the I-Light is in the middle, with the Shimano at around the D7 at € 110 (around £70) and the SON around € 200 (£130ish).
Manufacturer website: www.sram.com The i-Light D7 is available widely in continental Europe. In the UK it should be available to order via dealers.
ISSUE 29 MARCH 2008 VELOVISION