Busch & Müller IQ Cyo R N Plus

Busch & Müller have been manufacturing bicycle lights in Germany since 1925. They offer a wide range of interesting products with most of their lights being targeted for the European market where, unlike here in the U.S., there exists strict standards for bicycle lights.

One of the unique aspects of most “Euro-style” headlights is that they have controlled beams that place the light where it’s needed on the road, similar to well-designed automotive low beams. In contrast, a majority of the lights manufactured for the U.S. market have less-efficient round beams like flashlights. Lights with round beams work reasonably well, but for the same output, a light with a well-controlled beam will provide superior performance on the road.

When a bicycle is used for transportation on a daily basis, the advantages of dynamo-powered lighting become apparent. Eliminating the need to charge batteries as part of a daily routine is reason enough to prefer dynamo systems (there’s nothing worse than getting caught in the dark with fading batteries and a long ride ahead of you). Knowing that reliable lighting is always available with the flip of a switch makes a bicycle more like an automobile and encourages evening and nighttime use. Plus, a dynamo system eliminates the waste associated with charging and disposing of batteries.

Until recently, many dynamo-powered lights were under-powered and only marginally acceptable, but with the advent of ever more efficient LED emitters, the latest crop of dynamo-powered headlights have finally crossed the threshold from “barely enough” to “more than enough”. Among these are the Schmidt Edelux, the Inoled Extreme, and the subject of this review, the Busch & Müller IQ Cyo. These lights aren’t as bright as the brightest battery-powered systems (many of which are inappropriate for use in traffic or on multi-use trails because of their unfocused beams), but they are perfectly suited to on-road use in urban and suburban commuting conditions.

The IQ Cyo is the latest in a long series of dynamo-powered headlights from B&M. It uses their best, rear-facing LED emitter and their most advanced mirror to date. A rear-facing emitter combined with a well-designed mirror make it possible to precisely shape a beam for a specific use. In the case of the IQ Cyo, there are two beam patterns available. The standard IQ Cyo is the brighter of the two with an output of 60 lux. The IQ Cyo “R” has an output of 40 lux. Both use the same emitter, so what’s the difference? The standard beam is shorter vertically; in other words, the beam is is more tightly focused and covers a shorter patch on the road, albeit more brightly. The R’s beam is longer vertically; in other words in covers a longer patch on the road, though because the light is spread out further, it appears less bright on the road surface. [Peter White has some beam patterns here.]

Our test light is the IQ Cyo R N Plus with the taller beam, standard switch, standlight, and integrated reflector. This configuration makes the most sense for urban riding in mixed lighting conditions at relatively low speeds. It puts down a nicely controlled, remarkably bright beam that covers the lane width without spilling too much light off to the sides or into the night sky. If you’re accustomed to halogen dynamo headlights, the Cyo R will be a revelation. On paper, it shouldn’t be able to compete with my twin Fenix L2D’s, but in practice it actually illuminates the road more effectively due to its well controlled beam. For commuters who ride on a mix of urban, suburban, and rural roads at relatively low speeds, the Cyo R is perfect. For those who ride in rural areas at higher speeds, the standard model, with its brighter and more tightly focused beam, might be a better choice.

The build quality of the IQ Cyo is typical B&M ; functional without being unnecessarily extravagant. The case is molded from high quality plastic and the fork crown mount is steel. I particularly like the positive feel of the switch on this light; it’s a step up from the switches on prior B&M lights I’ve used, some of which were a little “soft”. The light comes wired with a long main lead for connecting to a dynamo hub, and a shorter lead for adding a tail light if desired.

Standlights are an important safety feature and I wouldn’t purchase a dynamo light without one. I timed the IQ Cyo standlight’s runtime at over 4 minutes, more than long enough for normal use on the road. I always recommend carrying a second, small backup battery-powered light in the event of a flat tire or other mechanical failure.

The IQ Cyo is available in four configurations as a dynamo light:

  • IQ Cyo N Plus (standard on/off switch, standlight)
  • IQ Cyo Senso Plus (auto on/off, standlight)
  • IQ Cyo R N Plus (tall beam, standard on/off switch, standlight)
  • IQ Cyo R Senso Plus (tall beam, auto on/off, standlight)

B&M’s nomenclature can be more than a little confusing. Here’s a glossary to help sort out the cryptic names:

  • N = standard on/off switch
  • Senso = ambient light sensor automatically turns light on/off as needed
  • R = tall beam
  • Plus = standlight

Our test light came paired with a Shimano DH-3D71 Ultegra-level dynamo hub mounted on a custom Soma Double Cross commuter. The Shimano hub performed well. I’d offer more input on the hub, but there’s not much to say other than it worked, it produced no noticeable drag, and it provided the correct amount of current to power the light.

Prices have really come down on dynamo systems in the past few years as the technology has improved and the competition has heated up. The IQ Cyo sells for approximately $105—$110 depending upon the particular model. A complete system including a light and a wheel built on a dynamo hub will run approximately $300 (the price will vary depending upon the wheel components chosen). The price may sound a little steep at first glance, but when you consider the fact that the LED emitter will last a lifetime and there are no batteries to charge or replace, you can see it’s a good investment for a full-time commuter.

Dynamo-powered lights have finally come of age and can now provide 100% reliable light at a level that is far past “good enough”. The IQ Cyo is one of the best available, and with a price that’s approximately 50% less than its main competitors, it represents one of the best values in a light for serious bike commuters. Highly recommended.

Many thanks to The Bicycle Business in Sacramento, CA for supplying the test bike and lighting system for this review. —Alan

44 Responses to “Busch & Müller IQ Cyo R N Plus”

  • henryinamsterdam says:

    Thanks for the in-depth overview. I’ve had an IQ Cyo on my city bike, also powered by a Shimano hub dynamo for about a year now. A Spanninga SPX LED taillamp with standlight is on the rear of the bike. It lives outdoors in all seasons in wet, cold Amsterdam and it all still functions as when I installed it. Here in sandbox safe Amsterdam this level of light is probably overkill but as the owner of a bike company I get to play.

    The only issue I’ve had with the IQ Cyo (and many other B & M lights) is that the switch has never functioned properly; both the “on” and “sensor” positions are always on. Maybe the poor sensor just never gets enough light in cloudy Amsterdam to think it’s daytime. Of course I can send it back for warranty but that’d be a hassle on a bike I ride every day. Mostly I just leave it on. And why not? The friction is negligible and the LED’s will last indefinitely.

    All in all LED headlamps have really come of age. Now they just need to drop in price enough to install them OEM on all of our city bikes. That’s just not possible with a €100 headlamp. We do use the Basta Pilot LED on many bikes, though. Not quite as good but totally reliable and half the price.

  • ksteinhoff says:

    Darn you, Alan.

    Now I’m going to have to go out and buy one of these things. You answered all my earlier questions about taillights and standlights, so now I don’t have an excuse not to upgrade.

    It sounds like I can retire my secondary light, too.

    Maybe I need to have a yard sale of good, but not best, generator lights.

    Is Peter White still the place to get them or have you found another vendor?

    One other comment: since the LEDs will last forever (or MY lifetime, at least) and the drag is minimal, I don’t see any reason NOT to run them all the time. The senso just adds one more point of failure.

  • Lovely Bicycle! says:

    Off topic, but that last photo is so nice! What camera was that taken with?

  • Alan says:


    Sorry, Ken. ;-)

    You’re correct, you won’t need a secondary light with the IQ Cyo.

    B&M lights are available from a number of shops around the country. If you don’t have a shop in your area that has them, Peter White is certainly a good source. The Bicycle Business provided the light for this review and they stock B&M (of course). You can contact them by following the link at the bottom of the review.


  • Mohjho says:

    Dang, thats one sweet Double Cross..the light is nice too.

  • Alan says:

    @Lovely Bicycle


    The camera was a Canon 50d with a Tokina 11-16 f/2.8 lens set at 16mm. The exposure was 1.6 sec at f/2.8, ISO 100. I had the flash unit set to second curtain to get the trailing light effect.

    I hope that helps-

  • ksteinhoff says:

    OK, Alan, you made me do it. I ordered mine last night.

    I may need you to write a note to my wife.

  • Alan says:


    Oh boy, I’m in trouble now. Please tell your wife I said “sorry”.

  • KWW says:

    Great article. Two points to hammer home:
    The reverse reflector really makes this design stand out above all the rest.
    The Schmidt E-delux has the same ‘guts’ as the B+M, namely LED and reverse reflector.

    I have an Edelux and people riding in the opposite direction always compliment on how bright the light is.

  • Random Ray says:

    Jees , does it come with a cool retro look so I can put it on my old bikes ? Alan just make a form letter so everyone can give it to their wives or husbands . LOL

  • Alan says:


    Dear Madam/Sir,

    Please forgive your spouse for spending too much money on bike parts. It’s my fault.


  • Chandra says:

    Great article, Alan!
    I have made myself a promise that I will get a dynamo light combo next year.
    May be even a new bike to go with it? :)

  • 2whls3spds says:

    Now if they would just offer it in a Chrome housing so it would look proper on a vintage Raleigh…


  • Random Ray says:

    Thanks Alan , now whenever you post really cool stuff you can just post your permission note . ;-)

  • Paul Rivers says:

    Are you going to be reviewing other modern dynamo lights, like the Superova E3 and the Schmidt Edelux alluded to in your previous post? Would love to see a comparison – the E3, for example, is a very different light (in terms of where it puts the light on the road).

    As I’m considering which to buy myself, I’d love to see it. :-)

  • Alan says:


    I hope to review the Edelux in the not-too-distant future and provide a comparison to the IQ Cyo, but I don’t have plans to review the Supernova at this time.

    You may have seen this already, but Peter White provides beam shots of all of these lights at the following link:

    PW Beam Shots


  • dave says:

    Thanks for the update – I commute in a rural area and have been using some of the higher-end battery light systems – I’ve been wanting to switch, just was not certain any of the dynamo systems were powerful enough.

  • Surly John says:

    Thanks for the review Alan. I ordered mine from Peter White yesterday. I have been on the fence for a month or more and you helped push me over. Since I commute in true darkness much of the winter I went with the non-R model. I’ll use a battery LED for up close if I feel the need. So now what to do with the Schmidt E6? Oh well, I’m going from good to better and I decided to get a wired tail light as well. :)


  • Fábio Caparica » del.icio.us entre 14.08.2009 e 23.08.2009 says:

    […] EcoVelo » Blog Archive » Busch & Müller IQ Cyo R N PlusBusch & Müller have been manufacturing bicycle lights in Germany since 1925. They offer a wide range of interesting products with most of their lights being targeted for the European market where, unlike here in the U.S., there exists strict standards for bicycle lights. […]

  • Zane Selvans says:

    I ordered one of these from Starbike in Germany for my partner one of these last year (or early this year?) when she smashed her old plastic B&M headlight. It’s awesome. I half-heartedly hope that I’ll smash my own IQ Fly so I can justify getting one someday :)

  • How to Install B&M IQ Cyo R N Plus Headlight — Palm Beach Bike Tours says:

    […] review on one of my favorite bike blogs, EcoVelo, tipped me over the edge. Alan@echoVelo promised to write a letter to spouses because his […]

  • ksteinhoff says:


    You made me do it. It arrived Monday. I’ll have to look at a map before I order anything shipped by ground from CA to FL. Not only do I have to print out your letter to my spouse, but I have to replace the carpet I wore out checking to see if it had gotten here yet.

    I can’t match your review, but I DID put up a video showing how I installed it.


    (Sure glad I found out how to remove the block to your site that my spouse had put on my browser. Every time I’d click on echvelo.org, it’d take me to Bike Accessories Anonymous (BAA).)

  • Surly Long Haul Trucker (LHT) Touring Bike Build, Modification and Review | Aushiker: Bicycling & Hiking in Western Australia says:

    […] My current thinking is along the lines of Bush and Muller IQ Cyo R N Plus as reviewed by EcoVelo and installed by Ken at Palm Beach Bike […]

  • 2whls3spds says:


    B&M is making the Cyo in a Chrome Housing….now to find one!


  • EcoVelo » Blog Archive » Road Test: Breezer Uptown 8 says:

    […] with the latest LED offerings from B&M such as the IQ Cyo we recently reviewed (read about it here). My review bike is a 2009 model and I see the headlight is changing to a “Basta Pilot” […]

  • Chandra says:

    Alan et al.,
    Are there any significant differences between the SON hub and the Lumotec hub?
    I know the SON hub costs more.
    Is the SON worth the extra money?
    Am I going to see significant differences between the Lumotec and SON?
    Peace :)

  • Alan says:


    Just to clarify so as to not confuse others, that’s a SON dynamo hub versus a Shimano dynamo hub, not Lumotec. The B&M Lumotec is the light.

    The Shimano has slightly more drag than the SON. Whether this is significant depends upon your pocktbook and priorities. I find the drag from either hub to be unnoticeable for commuting and city riding. If I was a randonneur or ultra cyclist I might be concerned about such things, but since I’m a garden variety utility cyclist, it matters not to me.


  • ksteinhoff says:


    (Alan, thanks for clearing that up.)

    I debated Son vs Shimano and decided to spend the extra money on the SON. My feeling was that I’d always wonder if I made the wrong decision if I went with the Shimano and, over the life of the hub, we’re not talking about a lot of money.

    I don’t regret my decision.

    On the other hand, I gave my son a Shimano and HE’S been happy.

    How’s that for not answering your question?

  • Chandra says:

    Thanks. I meant to write Shimano :)

  • Will Lockmiller says:

    I’ve got this headlamp on my tandem and it is really, truly bright. My wife and I have been using the standard Lumotec halogen lights for years for both commuting and touring on our singles. The light provided by a lone Lumotec is adequate for riding solo at speed on unlit country roads on a moonless night, but just barely. Also having to change the proprietary, expensive bulbs every 100hrs of use is a bit of a hassle. Recently my wife and I built up a Follis Tandem and wired a IQ Cyo R to a Schmidt hub and our jaws dropped at the amount of light that it put out on our first ride. Riding on a moonless night on a rough, narrow, pot-holey, gravel, tree-lined road, I had way more than enough light to ride at any speed we desired. I too wholeheartedly recommend this lamp over any other available modern model because of its price and performance. We’ll be switching our singles over to this lamp as well ASAP. BTW, here is a link to a photo of the tandem: http://www.flickr.com/photos/willjl/3946609321/

    Thanks for the review.

  • Chandra says:

    This might be an odd request! Can someone please compare this light to a Light and Motion ARC HID? This is my current light (until I buy a dynamo hub + lights). I would really like to know if the Busch & Müller IQ Cyo R N Plus will provide as much light as the L & M.

    Thanks in advance for your thoughts!

    Peace :)

  • Alan says:


    No dynamo light is as bright as an HID like the L&M ARC…

  • Chandra says:

    @Alan, Oh NO :(
    I was hoping that was not the case.

    Given my objective is NOT a) to be environmentally friendly and b) to have to worry about remembering to charge the batteries, I will still get a dynamo hub & lights :)

    I suppose I will keep the HID as a backup!

    Thanks, Alan!

    Peace :)

  • Alan says:

    I think you’ll find the IQ Cyo provides plenty of light. Personally, I found the ARC to be overkill.

  • Theodore Teo says:


    Thanks for the article. It, and your blog, is very inspiring!

    Just wondering … I noticed that most hub comparisons were between the SON and the Shimano. With a tighter budget, I went for the SRAM i-Light dynamo. Given the sealed bearings, that i-Light is German-made (hence, from a region where there’s a high interest and experience in hub dynamoes), and a very reasonable price of circa USD65, I went for it. But do you or anyone know of any comparison with the SRAM i-Light?

    I know it’s after the fact for me, but it’ll be interesting to know. And like you mentioned to Chandra, drag is not so much an issue for me as a commuter either. :-) Nevertheless, a comparison would be interesting.


  • henryinamsterdam says:

    Theodore, I’ve no scientific data but the Sram dynamo hub I used for year had noticeably less friction than any of the Shimano dynamo hubs… but we only use the basic, bolt-on models for roller brakes. Even then you can’t feel any of them while cycling.

    However we don’t fit the Sram to our bikes because there’s no decent hub brake available for city bikes. The i-brake was so horrible they had to quit production so now there’s only a disk or rim brake available. Shimano offers the excellent roller brakes in various flavors.

  • Theodore Teo says:

    Hi Henry

    Thanks for the insight. That’s very promising to hear. Sounds like you have a fleet of bikes and experience with Shimanos too. :-)

    Fortunately, I didn’t order the i-brake versions. I use rim brakes so it would be ok, but it also means that I can’t use white wall tires as the brake dust would be horrendous!

    Thanks again!


  • henryinamsterdam says:

    Actually I own a bike company (WorkCycles) with two bike shops . In addition to the feedback from thousands of customer bikes we also use our employees’ and families’ own bikes to test and compare components. Far better to know learn about the parts and designs on our bikes before selling them to several hundred customers.


  • Phuski says:

    Off Subject:
    In my search for a dynamo/brake front hub to outfit an old bike project of mine, I came across this interesting article.

    Although I will be taking notes of elements from this article to complete my research, there was a specific detail on the pictures of the bike that was used for this test for which I would like to know more of: This Soma Double-Cross bicycle was outfitted with a very decent looking handlebar.
    What brand & model of handlebar is this ?

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  • chris says:

    Can this light be used in conjunction with a dynamo powered tail light, having both being plugged into the front hub?

  • Spencer says:

    Chris–Absolutely. I have this light on 2 of my bikes. My Brompton has a Son Schmidt hub with this headlight and a generator-powered taillight. My wife’s Peugeot has a SRAM i-light hub running this headlight and the B&M 4D Plus rear light (fender-mounted). B&M (and Peter White, for that matter) actually suggests that you run a tail light in conjunction with this headlight. I love the clear-cut lens pattern; it lights up multi-use paths very efficiently.

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