Busch & Muller DToplight Senso, a bit dusty after my morning commute

My Experience:

One week of using the DToplight Senso for commuting, including several night and dusk trips (approximately 20 miles of nighttime riding) on an Azor Secret Service bicycle.

RESULTS:

Style: 4/5
Functionality: 5/5
Build Quality: 4/5
Brightness: 4/5
Installation and Instructions: 3/5
Battery Life: N/A (not tested long enough yet)

Summary:

The Busch & Muller DToplight Senso is a battery-powered rear bicycle light designed to fit on the end of a european-style rear rack, something that is somewhat difficult to find in the United States currently. It has the capability of attaching at either 50mm or 80mm screw width. The light itself has two rear-facing LEDs and two additional LEDs that point towards the sides of the light casing. The light requires two AA batteries.

The light casing has to fit up and under the rack, very carefully

Installation:

Installing the Busch & Muller DToplight Senso was a bit daunting at first, because of two things. First, documentation is completely lacking in the packaging – there is literally none. Second, the fit on the bicycle fender is shockingly tight. Lastly, the screw mechanism for the lights is opposite of what is normally expected. The DToplight is attached by included screw/bolts, which are square and flat at one end, inside the casing of the light itself, along with a couple of washers. First, however, one must pierce the semi-perforated holes in the light’s casing for the appropriate width, either 50mm or 80mm. Once the screws are installed, the ends point out of the back of the case, which makes attachment to the fender even trickier.

I can’t emphasize this enough: be careful, as the fit of the light is extremely tight. The light back casing should be fit first, by inserting it up and underneath the rear rack. The light is too wide to just fit straight onto the fender, at least on the Azor Secret Service. The only way I could get this to successfully fit was to put the front half of the light on after the rear half was firmly attached to the rack. I also had to push much harder than I initially wanted to in order to fit the front of the light onto the back section.

Style:

The light is pretty much in the style that I would want for a rear light on a classic-looking bicycle, minus the bulbous protrusion in the center. I actually wish the light had matched the original reflector in design, but the design is close enough.

Functionality:

4 LEDs = a pretty bright light, especially in comparison to the fender light

The Busch & Muller DToplight Senso has three settings- on, off and “senso.” The senso setting automatically turns the light on if the bicycle is moving and there is an appropriate darkness level. Additionally, this setting is also smart enough to serve as a standlight as well- it waits a few minutes before shutting off when the bicycle has stopped moving. In my experience, the senso feature worked flawlessly. In accordance with laws in some european countries, this light does not have a flashing or blinking setting as most U.S. lights do.

Build Quality:

The light seems well made, overall. Only the switch at the bottom of the light seems a bit loose, in my opinion. Fortunately, this light can probably just be placed in the “senso” mode and left there almost all of the time, so hopefully the switch will not be a future quality concern.

Brightness:

The Busch & Muller DToplight Senso seems very bright, as can be seen in these two photos (one with my camera flash on, and the other with it off). I would always recommend having more than one rear light, however. I believe the light is certainly bright enough. I am not so sure, though, about the light having additional visibility to the sides of the bicycle – this did not really seem true in actual use.

Closeup of the light when on

Battery Life:

Not tested long enough to know. I will report back when I do!