Busch + Müller IQ-XM Speed front light review

The Busch + Müller IQ-XM Speed is, first and foremost, a light designed for bike paths and urban riding.

It’s well-made and has a tidy design. However, the beam lacks consistency and punch.

If you don’t need StVZO compliance, it’s unlikely to be a first choice. But if that is a requirement, the inclusion of a high-beam option makes it more user-friendly.

Busch + Müller IQ-XM Speed specifications and details

At its heart, the Busch + Müller IQ-XM Speed is an StVZO-compliant light.

There are three standard power modes, plus a high-beam setting that ups brightness and gives extended visibility forward and to the periphery.

The light doesn’t feature an integrated power button. Instead, power and all mode controls are handled via the wired remote.

The remote lights up blue to indicate when you’re in high-beam mode and green when in any of the standard modes.

The light body attaches to a twist mount that positions it tall on the handlebars. The mount attaches to the bars via a bracket with a screw-to-tighten lever to fasten it down.

There’s a separate battery pack that’s designed to sit on the top tube. It’s secured in place with an elasticated Velcro strap.

The 4,600mAh battery pack has an array of four blue indicator LEDs to show remaining battery charge. It connects to the light with a screw-in connection, and can also be used as a power bank thanks to its micro-USB port.

The battery has a curve on the underside, which makes for a better fit on rounded frame tubes.

It comes complete with an EU plug (the light is retailed in and shipped from Germany), although you can charge the battery via a USB-A-to-micro-USB cable easily enough.

Run time on full-beam mode is said to be 1 hour 30 minutes, while Busch + Müller claims the full beam is capable of putting 170 lux down onto the road.

‘Lux’ is the unit of measurement given for the amount of light landing on a surface, compared to the commonly used lumen count: the unit of measurement of the light put out by a light.

Busch + Müller IQ-XM Speed performance

Installation of the IQ-XM Speed is simple. The bracket opens right out, making it easy to get in position, and offers the benefit of being able to fit to most diameters of rounded handlebars.

Once the latch is closed, it tightens with an integrated knurled screw. There’s no need for an Allen key to be used.

In fact, I found the bracket so easy to use that I tended to remove it with the light as one complete unit.

If you want to leave the bracket in place, there’s a twist-to-secure mechanism that ‘locks’ the light down. When in place, you simply turn the mechanism the other way for it to release the light head.

The remote is attached with a rubber band, with a tab at the end to aid finger grip.

It’s attached semi-securely at one end, reducing the chances of it being lost. It’s a small detail, but one I appreciate because I never miss an opportunity to drop and lose small parts.

The remote wire isn’t particularly long, and I’d prefer it to be longer to enable me to position the remote button closer to the brakes.

The battery pack’s curved underside doesn’t come with any padding. Instead, the plastic underbody with longitudinal grooves is put in direct contact with the frame.

Mounted to a slender steel top tube, additional friction from some kind of padding would have been welcome.

That said, the Velcro strapping is broad, elasticated and can be tightened comprehensively to hold firm.

In StVZO mode, the beam has a clear customary cut-off at the top. It also features distinct bright spots.

While the overall spread is narrow, there is a broader spot close to the bike, with a gradual fade to the outer edges.

It gives better peripheral awareness than a more uniformly narrow or tunnel-like beam, improving confidence on darker roads. You can also spot junctions more easily and are aware of any obstacles close the kerb.

Switching into high beam when there’s no traffic doesn’t do much to increase the spread of light, but it does somewhat fill in the top of the beam to increase reach and visibility upwards.

The high beam enables you to ride faster than you otherwise would in StVZO mode, but I would still not want to use it on country lanes, preferring instead a broader beam.

There’s also a patchy quality to the beam in either mode, and it was disconcerting to ride with at first. There are definitely more even beams featured by competitors – StVZO and non-StVZO alike.

You can see the obvious demarcation between the brighter and darker areas of the beam, and they naturally shift with the movement of the bike over the ground.

Although your eyes do adjust to this somewhat, it’s hard to overlook the issue despite the anti-glare properties the light is purported to give.

Unfortunately, I found the beam to be too uneven to feel completely comfortable using it outside of an environment with ambient street lighting, which is limiting considering the light’s punchy price.

On another note, Busch + Müller claims the IQ-XM is suitable for “road, gravel and mountain bikes”, but although the light may fit those kinds of bikes, the beam quality limits its usefulness compared to the best bike lights.

Otherwise, it's a well-made and straightforward light to set up and use. I also found battery life to tally closely with the claimed run times.

Like many StVZO-compliant lights, the IQ-XM Speed ships and retails from Germany, one of the very few territories where StVZO compliance is mandated by law.

Busch + Müller IQ-XM bottom line

The Busch + Müller IQ-XM is a well-constructed StVZO light that is uncomplicated to set up and use.

It has additional functionality with a (non-StVZO) high beam, which inspires more confidence when you need a little extra light.

However, overall the beam is patchy and really best for urban riding and commuting on lit bike paths and roads.

Even with those limitations, it remains an expensive light, considering performance against the competition.