How we made the doubleplusmusic bike trailer

By
Antranik
– September 25, 2011Posted in: Bicycling, The Constant Awesome

It took me months to get all the pieces together needed to make this hap­pen. When I finally had every­thing I needed, my brother and I built this dou­ble­plus­mu­sic trailer in a cou­ple days. I have included more details on the setup at the end of this post.

Took Instep trailer and stripped every­thing but it’s frame… put a mock (unat­tached) wooden floor and hooked it up to the bike. We real­ized when it’s hooked up to the bike the floor isn’t flat anymore.

So my brother Armand started cut­ting a block of wood to use to adjust the angle of the floor.

And now the floor is level, yay!

Even though the floor was level.. we have a cou­ple prob­lems: the cen­ter of grav­ity was raised by a few inches… and that front bracket that was meant to retain the subwoofer-box, was now use­less.. errr… so we tried to find other solutions.

So we real­ized if we made the hole larger in one of the con­nec­tion points it would allow the final con­nect­ing piece to bend down a bit more help­ing to make the floor much more level. And it worked!

We finally attached the floor. Note how we had to cut out parts of the wood to get it to fit. The over­hang allows us to have more space and the wood is very solid 3/4″ hard­wood that barely bends if i stand on it and bounce it.

In this pic: two black wooden boxes (one is the sub and the other is the top) are stacked. See the orange strap that goes through the holes in the wood? That is a ratch­eted tie-strap that will keep the speak­ers in place. We con­nected a piece of wood to the top speaker to have the straps go through that and use it as a han­dle for the top piece when we take it apart.

Next morn­ing… went to the hard­ware store to get some dif­fer­ent screw lengths and wash­ers… and then con­nected the trailer up to the bicy­cle again and lo and behold the floor over­hang was too long and rub­bing against the rear wheel. Woops! So here I am cut­ting two inches off. And no my fin­gers weren’t there when I was actu­ally doing the cutting.

My brother rec­om­mended we strengthen and rein­force the orig­i­nal frame and so we got this metal piece to beat peo­ple with and cut it to the proper length.

Holes drilled and the metal piece is installed per­fectly b/c it’s set just behind the sub box and this holds the box in its posi­tion for GOOD.

The rein­force­ment has a per­fect hairline-gap. One of the mer­its of being an OCD-cat.

A mock instal­la­tion of the ampli­fier. I put some foam that was orig­i­nally used for sound absorp­tion above and below the amp to absorb road vibra­tions. Armand cre­ated the wooden panel that’s on top of it and I cut the cor­ners out so it would fit bet­ter. The box of sprite cans are to com­press the foam and mea­sure what the height of the new wooden shelf would have to be. Note: The foam is not cov­er­ing any of the vents of the amp. It has vents in the front to back with fans and this would be fac­ing the front of the bike (not the back) so it gets tons of air flow when rid­ing so I’m not con­cerned about heat build up. I’m only con­cerned about humid­ity but it is rarely over 20% humid­ity in LA.

Cut four 2×4’s into 6″ pieces to act as the sup­port for the 2nd-floor which will be for the gen­er­a­tor. It took a cou­ple cuts to get them to per­fect height with an uneven jig­saw blade. O_o

We just mounted the amp only to the top-rear mount with screws and rub­ber washers.

Here’s another view of the rear mount. Since it’s only mounted to the top-rear, the con­nec­tion point acts like a hinge that allows the amp to swivel and pro­vides tol­er­ance for move­ment (between the foam only) so it will have a less direct impact from the vibra­tions on the streets and pot holes.

The gen­er­a­tor floor is now offi­cially mounted to the 2×4 blocks.

Gen­er­a­tor placed on top and ratch­eted down with tie straps through a hole made in the wood floor.

Hooked up to the CAAD 9 road bike, ready for the first test ride!

View from the rear: It’s a faise. All it needs now are arms stick­ing out the sides… and a mon­o­cle over one of the small woofers and then sub­mit to r/proper.

Side view

NO RATTLES, NO VIBRATIONS, ALL IS SAFE. dou­ble­plus­mu­sic trailer v1.0 is tight.

Here’s our first test ride with it!

 

But we kept on with the improvements

My brother added side and rear walls to act as a sound shield for the generator.

Wheels painted white.

And the wood was painted black.

These walls now make the gen­er­a­tor noise reflect upwards toward the sky. This is a trick many gen­er­a­tor users do: putting a genny in a large box makes the noise deflect toward the sky.

Sexy fend­ers cre­ated using thigh-bended 25-gauge alu­minum that are then held with L-brackets at the ends.

ET VOILA , ++music trailer ver­sion 1.2 (went from 1.0 to 1.2 in 24 hours). doubleplusproductivity.

dou­ble­plus­mu­sic trailer.

We fin­ished this trailer and debuted it imme­di­ately on another epic mid­night ridazz ride in LA, this one was coin­ci­den­tally called, “The Worlds Biggest Bike Song” and it was dope.  Here’s some footage of the ride, includ­ing the trailer.  :D

Specs

  • Trailer: Some Instep trailer
  • Power: Honda EU1000i (900w con­tin­ious, 1000w max)
  • Sub: Audiopipe 15″ sub­woofer (1000w RMS)
  • Tops: Klip­sch KLF-C7 = 90°x60° Trac­trix Horn and Two K-1062-KV 8″ Woofers, 99db sen­si­tiv­ity, 38lbs. (150w RMS, 600 max)
  • Amp: QSC PLX 3102

How this all started…

I wanted to cre­ate a music trailer for a long time and in 2010 I started to col­lect the pieces together to make it hap­pen.  I used to have a boom­box on the rear rack of my bicy­cle attached with bungie cords but it was only able to pro­vide music for a short dis­tance and the sound qual­ity was poor.  I con­sider myself a con­nois­seur of music and so I wanted to have pow­er­ful, clean, full-range sound. What’s the point of play­ing Deep House if you have no sub­woofer to repro­duce the “deep” part?  Half the song would be miss­ing, I thought.  So I decided it was a must that the sound trailer have a sub­woofer so that I could hear the lower frequencies.

Sub­woofers recre­ate the lower fre­quen­cies by mov­ing a lot of air and that requires a lot of power.  I did my research and real­ized I wasn’t going to be able to run a large setup on a car bat­tery for very long and I kept my eyes out for those small Honda gen­er­a­tors on craigslist.  I was able to snag a Honda eu1000i, which is about the weight of a car bat­tery, that was almost new (if not new) for $630.  This was the largest expense and made me almost not be able to make rent for that month, but it was worth it.

I found an Instep trailer for $40 from craigslist.  These trail­ers are very fre­quently for sale on craigslist because par­ents buy them for their kids and they quickly out­grow them or never use them to begin with.

When I started doing my research for ampli­fiers I wanted a very high qual­ity ampli­fier that was going to be able to make full use of all the gen­er­a­tor power I had on tap.  The prob­lem was that amps get VERY, VERY heavy if they are very pow­er­ful.  I was keep­ing my eyes out for Crown and QSC amps because I wanted the sound qual­ity to be very good.  I dis­cov­ered the PLX Series of QSC amps and their specs were absolutely badass.  Not only do they pro­vide tons of clean power but they also only weigh 20 pounds!!!  I had cre­ated a live-bookmark on craigslist to catch any QSC PLX amps and after a few weeks I got lucky!  I found a woman sell­ing tons of sound equip­ment all together includ­ing a QSC PLX 3102.  I told her I only want that one item and she gave me this $1,200 ampli­fier for only $240!

I found the 15″ sub­woofer able to han­dle 1000 watts RMS again from some­one on craigslist and it only cost me $20.  I opted for a ported box for the sub­woofer, as opposed to a sealed one, so that I could hit the lower fre­quen­cies if need be and got the box from a local stereo shop for $60.

The last piece that I needed to start on the project were the tops: the speak­ers that would be ded­i­cated to repro­duc­ing the mid to high range fre­quen­cies.  This was a bit dif­fi­cult to find on craigslist as most of the speaker sys­tems were often lim­ited to just 100 watts RMS.  I got lucky when I found some­body sell­ing a Klip­sch KLF-C7 on craigslist for $240 (nor­mally $600) that was able to han­dle quite a bit of power and was going to be per­fect for clarity.

As you can tell I used craigslist a lot and it’s because I know how to setup live book­marks so I’ll eas­ily know when some­thing I want is listed.

In hind­sight, I don’t rec­om­mend any­body use the instep trailer because they use wheels you’d find in Toys-R-Us prod­ucts. The hub bear­ings got really messed up after a full night of rid­ing this through the streets of Los Ange­les in one night.  We ended up mod­i­fy­ing the trailer fur­ther, mak­ing a dust-proof, sealed enclo­sure for the ampli­fier to use the trailer at Burn­ing Man in 2010 and it was very awe­some to have great qual­ity mobile sound when­ever we wanted.

We will be redo­ing this music trailer using another trailer that I got from craigslist that has spoked wheels (read: real wheels) with an axle between them so the bear­ings could def­i­nitely han­dle the 160 pound load on the rugged city streets.  I have to find a way to angle the tops up a lit­tle bit because when we are in a large group of rid­ers, the peo­ple act as a wall and absorb all the sound.   If you’re in a group ride with hun­dreds of rid­ers, 20 rid­ers bunched up together absorb a lot of the sound.  If the speak­ers were 6 feet in the air so that the sound would clear everybody’s heads, the music could then be heard for hun­dreds of feet!  But that’s a huge prob­lem as that top box weighs 40 pounds and lift­ing it up higher than nec­es­sary is kind of scary.

If you have any com­ments or ques­tions or sug­ges­tions please feel free to leave a com­ment below!  Go ride them secksy bicycles.


Related posts:

  1. World’s Light­est Road Bike at 2.7kg
  2. Hey Ass­hole! Yeah You, The One On The Bike!
  3. Stretches to do while rid­ing your bike with no han­dle­bars [Video]
  4. How to Moun­tain Bike Down­hill and Uphill Like a Badass (I mean, con­fi­dently and safely)
  5. Sing LOUD and FREE when you’re rid­ing your bike
Tags: