June 18th, 2007




UPDATE 9/11/2008: Look ma!  We have a whole website for the Speed-Vest now — you can sign up for news about the V2 vest, get yer press-blurbs on,
and stay informed about the 2009 Tour De Speed-Vest!
Furthermore, we’ve now got video of the vest in action here.
But if you’re looking for some fairly nerdy reading about how to make one of these yourself … read on!

The SPEED-VEST is a bicycle safety device and advocacy tool which displays the wearer’s current speed on their back in easy-to-read lighted numerals. It improves rider conspicuity while legitimizing bicycle speeds on the roadway. Originally conceived by Brady Clark and engineered by Mykle Hansen, it just won the Hub Bike Shop’s Bike Gadget Contest in Minneapolis, MN.

The system consists of a wheel speed sensor, a wearable numeric display and a small computer that does the thinking. The computer is an Arduino: an open-source embedded computing platform powered by an Amtel microcontroller. It runs for 6 hours on a 9 volt battery, and is about this big:

in the palm of my hand.


The numeric display is made from electro-luminescent wire, supplied to us by CooLight.com. El-wire glows brightly when supplied with a very small amount of high voltage, high-frequency current. It’s cheap, flexible and fairly durable. One AA battery can power the SpeedVest display for up to 6 hours.

... and it's pretty.


This project was my first foray into microcontrollers. Not knowing much about electronics, I imitated this circuit closely; however the Arduino platform, suggested by the members of Dorkbot PDX, was much easier to use than I had imagined and quickly became my new favorite computer.

I wouldn’t call the project arduous, but the most time-consuming aspect was probably soldering the circuit together on the Arduino’s prototyping daughterboard. Next time, I’m going to learn how to make my own printed circuit board.

soldering, soldering, soldering ...


Meanwhile, Brady designed a template for the el-wire digits, based on the digits in old Nixie tubes. It seemed appropriate — it’s almost the same technology, really. Since I had 12 pins to play with, and since you can only overlap so much el-wire, we put five digits on the right and seven on the left:

the stacked numbers template


We mounted the el-wire on a piece of black denim, taping on the template as a guide, using a technology the Coollight.com folks hipped us to: the Buttoneer. I don’t know how well it works for re-attaching buttons, but it’s great for this.

the buttoneer at work


We achieved sharp corners by running the wire behind the denim through a hole, and then back through to the front at another angle.

the view from behind


In order to display the SpeedVest for judging at the Gadget contest, we needed a mannequin. So, we borrowed another great piece of Internet advice. Witness below the birth of the creature known as “Packing Tape Brady”, made possible through the assistance of super-assistant Heather Anderson:

We were up most of the night before the event deadline: debugging code, writing up handouts, fixing bad solder, screen-printing text onto reflective backing, velcro-ing everything together, and arguing about the relative artistic worth of the digits zero and seven. The next morning, we got it all together and brought it to the Bell Museum with about 15 minutes to spare.


(Somehow we neglected to get a picture of it working — but it worked!)

Despite some excellent other entries (including the zoobombariffic Superman Bike!), we were tickled pink when the judges at the Bike-In presented Brady and myself with a $150 gift certificate from the sponsoring bike shop, the HUB bike co-op of Minneapolis. And what a gift certificate! This beautiful hand-drawn check would have been prize enough, even if it hadn’t been financially negotiable.

words don't do it justice.


The Speed-Vest will be undergoing speed trials in Portland, Oregon at an undisclosed test track this Sunday night. If you are interested in bringing the Speed-Vest to your town or event, or just want more info, please drop us a line:
info @ speed vest . com

83 Responses to “Speed-Vest!”

  1. revphil Says:

    i will bust this vest open like flavaflav busting a rhyme about Dolly Partons tits. EXPLOSIVE NUMEROLOGY!

  2. Mark in DUB Says:

    I’m afraid of possible negative effects on my health due to obsessive compulsion to maintain a constant speed of 23. That’s MPH, right? ‘Cause that’s pretty fast. I guess it would be possible, given a stretch of lightly used road that goes gently downhill forever.

  3. steev Says:

    This is so damn cool! At first I thot this was another “fake ad” of Brady’s, but it’s actually real! OMG! y’all rock!!!

  4. steev Says:

    oh i just realized, you never explained what you use to sense the speed and get that data to the microcontroller…

  5. mykle Says:

    It’s the sensor from one of the bike computers that the City of Portland was giving out for free at one point — a standard bike component. Electronically, it consists of a switch mounted to the seat stay and a magnet mounted to a spoke which closes the switch momentarily. Quite simple, really,

    (I didn’t know how to hook that to a pin on the Arduino, but i found the answer in the Spooky Arduino class materials: http://todbot.com/blog/spookyarduino/ )

  6. ladyada’s ranting » Blog Archive » Speed-Vest (take that, Leah!) Says:

    […] This vest uses a ‘nixie’-like numeric display system to show the speed of the cyclist. It seems that the builders used the hall effect sensor from a bikecomputer to calculate the RPMs on an Arduino and then turn that into MPH which is displayed using triacs (im kinda guessing here) […]

  7. Daily DIY Network - Science Projects Plans Guides » Blog Archive » “My Speed” bike vest Says:

    […] a light-up bike vest that lets people behind you know how fast you’re going. It uses electro-luminescent wire in the […]

  8. zach Says:

    Just to let you know, although on the arduino there are 13 labeled pins for digital I/O, the 6 analog pins can be also addressed as digitals. Just treat them as 14-19. (i.e. `digitalWrite(19, HIGH);`)

  9. mykle Says:

    Word to that. Figuring out how to overlap more digits would be the hard part, really, but getting a full 0-9 readout on the right-hand side is on our list for 2.0, along with integrating the el-wire inverter, triacs and arduino on a single board with a single power supply, and of course going wireless!

  10. DIY – Bicycle Speed Vest - SPEED-VEST, Brady Clark, Mykle Hansen, Bicycle, Arduino, El-wire, Nixi-Tube, Buecley's, Visibility, EL-wires - talk2myShirt Says:

    […] gear does get a lot of creative attention from the wearable electronic community as the Bicycle SPEED-VEST is another example to combine visibility with a touch of fun or practicality, depending on how you […]

  11. "My Speed" bike vest | Abiyaa Says:

    […] a light-up bike vest that lets people behind you know how fast you’re going. It uses electro-luminescent wire in […]

  12. SPEED-VEST shows of riders current speed in style - RoadCycler.com Says:

    […] Click here for a complete rundown of the project, and a ton of pics! […]

  13. KCJEVJEV Says:

    you should try it as a 7 segment display, not quite as cool but sounds like you could get 15 pins going.

  14. Speed Vest shows you how fast Bike is going! | zedomax.com - Obsessively profiling DIYs, HOW-TO,Hacks, Gadgets, Tech, Web2.0,and beyond. Says:

    […] ohgizmo, ladyada, mykle A+Featured, advocacy tool, bicycle safety, bike shop, biker, bikes, brady clark, conspicuity, […]

  15. Mike Says:

    Bud, only a guy with a girlfriend that cute can get away with the Saran wrap look AND the Robot dance move. Kudos!

  16. voon Says:

    COOL VEST… it can display the speed up to 99MPH… i’m wondering if that device can be used on a jet plane… lol

  17. e12ys Says:

    COOL VEST… it can display the speed up to 99MPH… i’m wondering if that device can be used on a jet plane…

  18. Speed-Vest! Says:

    […] Are you the type of person who love to show off, especially when it comes to speed? Well if you do, grab one of this Speed vest, a device that will let everyone know how fast you’re going with your bike. Equipped with electroluminescent wiring on the back and wheel speed sensor, it displays a bright numeric readout that states just how fast you’re moving in no uncertain terms. The vest runs on a 9-volt battery for six hours of use. [Mykle] […]

  19. » Chaleco con velocímetro para ciclistas tec.nologia.com Says:

    […] seis horas y lo mejor es que si sabes algo de electrónica te lo puedes hacer tú mismo … aquí tienes cómo se […]

  20. Jaket Motor Keren | Medhex Site Says:

    […] Dibuat oleh Brady Clark dan Mykle Hansen, Jaket motor ini berbeda, seperti terlihat pada gambar, pada punggung jaketnya, ketika kita sedang melaju kencang, ada indikator MPH (Miles per Hour), yang berfungsi memberikan informasi pada kecepatan berapa si motor kita melaju. Dengan menggunakan electroluminescent wiring dan beberapa komponen elektro yang tidak perlu tahu…  ( karena saya tidak mau tau) dan tentunya informasi ini bukan untuk si pengendara… mudah2an bisa memberikan cukup informasi bagi Polisi untuk memantau anak motor yang ugal2 an…. via here […]

  21. WinExtra - From the Pipeline – 8.23.08 Says:

    […] Speed Vest [nw] :: mykle systems labs – I’m sure the police would like this .. almost as good as having a bulls eye painted on your back […]

  22. Alan Says:

    Fantastic job on this project. I think it could be very helpful in road safety.

  23. Abhi Says:

    Awesome job on the project! Nice display and a different look from the regular 7 segment.

  24. Bicycle Vest: What’s my speed? | BikeHacks Says:

    […] For the full story, including an explanation of this very interesting picture below, click over to Mykle System Labs. […]

  25. GEARFUSE » Arduino Speed Vest Says:

    […] Link (via) Read More Cooline Evaporative Cooling VestThe ArtBus Spreads OutCredit Card Scans From Your Pocketed ArduinoDIY: Arduino XPort Shield BuildTrip Out: DIY Arduino POV Device TAGS: SHARE: Stumble Upon, Digg, del.icio.us, Reddit this, SlashdotSend to a FriendPermalink […]

  26. Gadget Train » Blog Archive » Arduino Speed Vest Says:

    […] Link (via) […]

  27. Display Your Speed With A Vest | Everybodyloveslen.com Says:

    […] read more on how the vest was designed, check out this article at mykle dot com. digg_url = […]

  28. Läufer haben eine variable Rückennummer bei laufrunde.de - modern running magazine Says:

    […] Mykle Hansen entwickelte im Rahmen eines Fahrrad-Gadget-Contests die “Speed-Vest”, welche – im Set mit Geschwindigkeitssensor und einer 9-Volt-Batterie – die aktuelle Geschwindigkeit des Radlers auf dem Rücken anzeigt. […]

  29. mcdave.net » links for 2008-08-25 Says:

    […] n mykle systems labs » Blog Archive » Speed-Vest! […]

  30. daveinglasgowscotland Says:

    we want this. bad. please sell it to a company who can build and dist it…i could really see it saving lives.

  31. Alternative Messages for the Speed-Vest - Urban Velo Says:

    […] week we learned of Brady Clark and Mykle Hansen’s invention, the Speed-Vest. The idea is that the cyclist’s speed is displayed on their back, which in turn shows […]

  32. HASENFARM | Textil-Tacho: Geschwindigkeitsanzeige für Verfolger Says:

    […] Wer Lust und Geschickhat, sich dieses Gadget nachzubauen, der werfe einen Blick auf Mykle Systems. […]

  33. EL Vest Shows Bike Rider’s Speed | only hacks Says:

    […] much more from his blog. He did make a kick-ass vest that displays his current speed. He calls it Speed Vest. It uses an Arduino to sense the speed and then display it on the vest using electro-luminescent […]

  34. Nathanael Ramos Says:

    I hope it will be distributed in Europe…

  35. Coureurs Geeks » Le gilet qui affiche votre vitesse Says:

    […] faire les malins. Cependant ce gilet est réservé aux cyclistes car la vitesse est récupérée via un capteur sur la roue. Mais un jour quelqu’un va bien nous bricoler quelques choses pour les […]

  36. Speed-Vest combines safety with speed display | MostReviews.com Says:

    […] more at Mykle Systems Labs via […]

  37. A jacket that displays the speed of your bike | Indian Autos blog Says:

    […] can check out how it was pieced together here Post a Comment or Leave a […]

  38. Stephen Skory » Blog Archive » Bookmarks for August 21st through August 29th Says:

    […] mykle systems labs » Blog Archive » Speed-Vest! – A cycling speed vest. It shows the speed on the back. […]

  39. Le gilet de sécurité qui affiche votre vitesse ! | Weelz.fr Le 1er Magazine Web du Vélo Urbain Says:

    […] pour un concours, à agrémenter la veste fluorescente de fils électro-luminescents qui affichent votre vitesse à vélo en temps réel dans votre dos ! De la même manière qu’un compteur vélo classique, un capteur est fixé sur la roue, qui […]

  40. Zot Says:

    You have the link to CooLight wrong. They only have one ‘l’ in the URL. The correct address is http://www.coolight.com/ (I have linked my name to it). Very cool project. Now I have to make one for my wife.

  41. mykle Says:

    Ohgoddammit. You’re right of course. Fixed.

  42. Pedaleiro » Blog Archive » Coisas interessantes Says:

    […] Mais detalhes no site do criador: Speed-Vest!. […]

  43. Pro Walk/Pro Bike - Day 2 - 09.04.08 « The Gas is Half Empty…The Pedal is Half Full Says:

    […] forward with biking and pedestrian issues – two in particular strike a chord… The first is a “bike vest” that displayed your real-time speed on the back of the vest. Decked out with reflectors and yellow […]

  44. Speed Vest - Team-BHP Says:

    […] rider conspicuity while legitimizing bicycle speeds on the roadway More can be found here: mykle systems labs Blog Archive Speed-Vest! […]

  45. thomasina Says:

    I want one please tell me how to purchase

  46. Right Brain Resource Blog » Blog Archive » Speed Vest Says:

    […] Clark and Mykle Hansen created a vest that lets bicycle riders show off how fast they’re […]

  47. GRK BLOG/ZINE » Blog Archive » Speed Vest Says:

    […] Clark and Mykle Hansen created a vest that lets bicycle riders show off how fast they’re pedaling: How does the vest […]

  48. Speed Vest « In The Spin Says:

    […] Speed-Vest! […]

  49. yann-g blog » Blog Archive Says:

    […] L’auteur a même gagné un “prize money” de 150$ pour son invention. Vous pouvez lire toute l’histoire du projet sur son blog […]

  50. “My Speed” bike vest | thekevinpipe.com Says:

    […] a light-up bike vest that lets people behind you know how fast you’re going. It uses electro-luminescent wire in the […]

  51. rory hyde dot com | blog Says:

    […] has been developed using the open source Arduino microcontroller and builds upon the efforts of others to produce similar […]

  52. Zot Says:

    Do you have the schematic anywhere? I am trying to build something similiar and I am having trouble determine how to ground the triacs and the inverter source. Also how you are getting the speed signal, are you wired to the bike?

    Lastly you need a announcement list so we can see, ext time you are in Seattle!

  53. petria whelan Says:

    We totally love your speed vest, can we buy one in London?

  54. Ken Says:

    The first thing that struck me when I watched your demo video was the fact that the cyclist wearing the vest has no lights and is almost invisible at many points! The Speed Vest is a very clever idea, but it is a poor substitute for several high intensity rear LEDs, if you want to be seen when riding at night.

  55. Bookmarks about Numerals Says:

    […] – bookmarked by 1 members originally found by silengz on 2008-11-30 Scott: mykle systems labs » Blog Archive » Speed-Vest! (via… http://www.mykle.com/msl/?p=10 – bookmarked by 2 members originally found by Jenahlattin on […]

  56. Authors make things too « PSU online Says:

    […] Jump to Comments Mykle Hansen, author of Help! A Bear is Eating Me! explains how the Speed Vest works. I rode on the back of the tandem bicycle struggling desperately to keep the camera level and […]

  57. Speed Vest, un chaleco con velocímetro : Blogografia Says:

    […] que se encienden o se apagan. Puedes ver más información sobre su construcción en la web de Mykle. Aún no está disponible comercialmente. Publicado en: Tecnologia 0 […]

  58. Pour faciliter la vie des bleus | hilpers Says:

    […] faciliter la vie des bleus Le gilet qui leur donne directement votre vitesse : http://www.mykle.com/msl/?p=10 Rassurez-moi, il n’y a aucun haut-fonctionnaire du Ministre de l’Intrieur sur f.r.m ? — Pierre […]

  59. [tech][ciekawostka] jesli komus wskazan licznika za malo | hilpers Says:

    […] jesli komus wskazan licznika za malo http://www.mykle.com/msl/?p=10 — c l i c k ‘n’ r i d e | kto nie pije, ten nie jedzie "Who wants to pedal bike uphill? The […]

  60. HiTechBlog » Speed Vest: vesta fluoriscenta cu indicator de viteza Says:

    […] Pentru a afla mai multe detalii despre cum functioneaza senzorul utilizat urmariti acest link. […]

  61. Michele Guerra Says:

    I think this is an amazing project, but I think the electro luminescent sticks are not well positioned: there are too much number for the first digit and not so many for the second one.

    It’s hard to go at 50 mph and in the meantime the low number of sticks used for the second digit make a low precision.

    The right thing is simply to exchange the digits 😉

    Sorry for my bad english.

  62. Speed Vest, un chaleco con velocímetro | Karakeando por la Web Says:

    […] que se encienden o se apagan. Puedes ver más información sobre su construcción en la web de Mykle. Aún no está disponible comercialmente. WPvideo […]

  63. Matt Says:

    You know, with 2 simple to use IC’s, you could fully realize 0-9 on boths sides of the vest, using only 8 pins from your Arduino device, since only 2 digits are ever illuminated at once.

    I can give you a quick rundown on how to do it if you would like, feel free to e-mail.


  64. Jor-ELL Says:

    My nipples are about to explode with excitement!

  65. Walk Oakland Bike Oakland » Blog Archive » Speed Vest: Part Vest, Part Speedometer Says:

    […] 70 mph. If you want more detailed info (and lots of it) on how it was constructed, check out Mykle Hansen’s site. Actually, it’s worth clicking that link just to see the photo series on the making of their […]

  66. Light Lane - Concept from Altitude’s Alex Tee and Evan Gant « Lewp’s Weblog Says:

    […] This reminds me of my personal favorite bicycle safety invention, the Speed Vest: http://www.mykle.com/msl/?p=10 […]

  67. Blizzard Says:

    If you were to make the digits segmented, you would need much less wire but still be able to make a similar look the way you have now.
    For instance:
    7 = —
    8 = ()
    9 = ()
    A little hard to do in ASCII but you can see that the 9 is made up from the parts of the 7 and the 8. 3 is only half a 8, etc.

  68. Streetsblog » DIY Safety Aids No Bike Injunction Can Stop Says:

    […] Mykle Systems Labs has fabricated a speed vest that shows a cyclist’s speed to vehicles that approach from behind.  It both increases visibility and demonstrates to motorists how much slower the bicycle is moving than the vehicle, which many motorists probably don’t realize if they don’t also ride. […]

  69. Jung-Kunsoo Says:

    hi speed best.
    I who am the electronics student of Korea put on. Your this that vest once which made makes and sees to want. Oh two purchased Roh EL wire, etc. inverter all. Absoluteness will not commercialize. Oh the program source which two uses in Roh knows. Entrusting gives. Cannot English but the mail tries to send like this. Reply to the reel which crawls begs a good fortune

  70. http://rich-niche.info/cookie/img/smilies/happy.gif Says:

    nice! [IMG]http://rich-niche.info/cookie/img/smilies/happy.gif[/IMG]

  71. MarkusB Says:

    Moin moin, schicker Beitrag auch wenn ich das etwas anders sehe 😀

  72. shanyan Says:

    very good!

  73. lopez hector (hectorlopez) 's status on Tuesday, 10-Nov-09 03:08:26 UTC - Identi.ca Says:

    […] cool http://www.mykle.com/msl/?p=10 a few seconds ago from […]

  74. tandem cycles for sale Says:

    i think the electro luminescent sticks are not well positioned, but it is somehow an effective project on my own observation.

  75. Making Cyclists Safer - Build18 Brainstorming | Hacktastico! Says:

    […] I can improve upon. Some really awesome bike-safety projects exist, such as the turn-signal jacket, bike speed jacket, bike brake lights, and laser bike […]

  76. GoodGNUs » Blog Archive » Cool Arduino Projects Says:

    […] bike vest: http://www.mykle.com/msl/?p=10 & […]

  77. Wheeled feedback « Thought Shop Says:

    […] “The SPEED-VEST is a bicycle safety device and advocacy tool which displays the wearer’s current speed on their […]

  78. Wheeled feedback « blog2sync Says:

    […] “The SPEED-VEST is a bicycle safety device and advocacy tool which displays the wearer’s current speed on their […]

  79. True Innovation Awards Blog » Blog Archive » ชุดนักปั่นอัจฉริยะ Says:

    […] ทีมงานเราลองไปเสิร์ชหาข้อมูลเพิ่มเติมก็ไปเจอเว็บไซต์อย่างเป็นทางการของเจ้า Speed vest ที่ http://speedvest.com/ ค่ะ ในเว็บนี้จะระบุว่าแม้ตอนนี้ทางคุณ Mike ผู้ประดิษฐ์เจ้า Speed Vest ขึ้นมา จะยังไม่ได้วางขายสิ่งประดิษฐ์นี้ แต่เขาก็ยังเปิดโอกาสให้ตัวเอง และทุกๆ คนเข้ามาร่วมดีไซน์ผลิตภัณฑ์กับเขานะคะ แถมเจ้าตัวยังไม่หวงวิชาด้วย ใครอยากรู้ว่าคุณ Mykle สร้างนวัตกรรมนี้ได้อย่างไร อ่านตรงส่วนนี้นะคะ http://speedvest.com/faq (สงสัยมีคนถามบ่อย เพราะอยากได้) หรือใครอยากทราบรายละเอียดลึกๆ ถึงขั้นว่าวงจรทำงานอย่างไร สร้างยังไงก็ไปที่นี่เลย http://mykle.com/msl/?p=10  […]

  80. Fresh Ideas in Cycling Safety | Bicyclerental.com Blog Says:

    […] The SPEED-VEST is a bicycle safety device and advocacy tool which displays the wearer’s current speed on their back in easy-to-read lighted numerals. It improves rider conspicuity while legitimizing bicycle speeds on the roadway. Originally conceived by Brady Clark and engineered by Mykle Hansen, it just won the Hub Bike Shop’s Bike Gadget Contest in Minneapolis, MN.  Mykle Systems Lab […]

  81. Safe Speed Vest with Speed Display on the Back | HACKOLOG - Amazing Hacks and Mods Says:

    […] Arduino sends signals to illuminate electro-luminescent wire into the back of the vest which displays the riders speed with just a small amount of high […]

  82. Advanced lighting techniques for bike nerds | Dorkbyte.com Says:

    […] speed vest tells those behind you how fast you’re biking by way of EL wire lights which illuminate your […]

  83. Craftsman Says:

    Contact the folks on TV about SharkTank – sell the idea for $1M and retire. I’d love to buy one – not techie enough to make one. Great job with the design, manufacture and publicity.

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