Saturday, March 5, 2016

Busch and Muller IQ-X Headlight: Brightest Dynamo Light Ever?

Just installed the IQ-X on my Singer! Haven’t been outside to try it (it’s pouring down rain outside), but based on spinning the front wheel, this thing is amazingly bright (they advertise it as 100 Lux; Peter White calls it “… the brightest dynamo powered light,” which I take to mean brighter than even the Supernova). I’ll post photos from the road as soon as conditions dry out a bit.

Front View. "Daytime" LEDs are visible at the top.

Rear View.

Another Front View.
A few notes:

— The silver version has a brushed finish that looks quite nice, but not polished like an Edelux. According to Peter White, the housing is also the heat sink for the LED.
— The light turns on an off with a pushbutton at the back, which is ringed by a blue light that comes on when the light is on. In the light’s location on my bike, the front bag will block this from my view, but YMMV based on where you put it on your machine.
— When the light is on, it’s always in “senso” mode, which turns off the main lamp during the day and leaves on a set of front-facing LEDs that act as daytime driving lights. After dark, the daytime running lights go off and the main light comes on. There is no “full-on-during-the-day” mode (you can’t have the brighter “nighttime” light on during the day).
— There are small slits on either side of the black band that let out light for visibility from the side.
— YES, the light can be mounted upside down! Just rotate the black mounting band 180 degrees and you’re good. No more need to buy a special light for upside-down mounting! Note, however, that the wires will still come out of the *bottom* of the light (not the top, like an upside-down model Edelux).
— Connecting my bike-mounted taillight was easy. The IQ-X has the same male connector as an Edelux (but on a wire pigtail, not part of the light). I had to connect the other wire lead to the frame to ground it, but with that done everything worked perfectly.
— The wire to connect to the front hub was *exactly* long enough (well, maybe 1/4th inch too long). Per the photos, my Singer’s front rack has the light mount on the lefthand side, so I need a little extra length to get across the bike from left to right, and from the front of the rack to the fork. If you mount to the fork crown or pretty much anywhere else, the wire will be fine.
— The wires, by the way, are standard B&M side-by-side conductor type, not the nicer coaxial that comes with the Edelux. B&M’s wires seem more flimsy to me, but on the other hand I’ve never had a problem with them.


  1. Thanks Eric. What about water? Is there any warning in the literature/instructions about allowing water into the lamp? B&M's Cyo specifically warns about this. I invert my bike to change flats, and I must prevent rain getting into the Cyo then. Just wondering if this is the same.

    1. Yes, the instructions say, "If the bicycle is transported or cleaned upside down, the headlamp has to be covered with a plastic bag to prevent moisture from entering through its bottom apertures."

      So, basically the same as the Cyo light.