Below are some pictures of the trailer mounted bike stereo I just made for a group of riders here in Knoxville.

The trailer is made of a commercial kiddie trailer arm mounted to a platform of plywood reinforced with 2x2's and fiberglass. the body is polyster impregnated fleece.

The stereo consistes of two 6.5" three way speakers that are driven by a 2channel car audio amplifier. The tunes come from an iPod wired directly to the amp. A car battery powers the unit. The switch on the front allows the amp to be turned off/on without unhooking the battery.

It's not light, but it is not as heavy to pull as you might expect. Th trailer tracks really well and you almost forget it's back there.

The stereo is loud and although it lacks propper bass response, it blows the battery powered boom boxes we were using out of the water.

Questions and comments welcome...

http://i64.photobucket.com/albums/h170/HandsomeRyan/1trailer.jpg

http://i64.photobucket.com/albums/h170/HandsomeRyan/1trailer3.jpg

http://i64.photobucket.com/albums/h170/HandsomeRyan/1trailer2.jpg

It makes me think of a hippo. :)

The Anti-iPod?

Very cool.

If you were already building a custom trailer, why not put the amp inside?

Also, how do you charge the battery and how long does it last?

If you were already building a custom trailer, why not put the amp inside?

Three main reasons:
•Amps get hot, VERY hot and go into power protect mode. Being on the outside gets it a little bit of air flowing when the trailer is moving.
• It's pretty standard in the car audio world to show off your amp(s). The manufacterers spent all the time chroming and painting them so they could be showed off.
• The yellow makes a nice contrast against the green and helps make the trailer more visible. (like a safety vest!)

how do you charge the battery and how long does it last?
Right now we are charging the battery by putting it back in Monika's car and driving around for a while. I'm working on securing a trickle charger so we don't have to waste gas to recharge it though.

We have not tested the limits of the battery but "on paper" the stereo should run at a reasonable volume for at least an hour or more. In real life it depends on so many factors from temperature to type of music being played. A deep cycle battery could improve play times but cost money that I don't have to spend.

Very cool setup, thanks.

http://i64.photobucket.com/albums/h170/HandsomeRyan/TrailerSound1.jpg

This is an MS Paint diagram showing just the stereo bits.

It makes me think of a hippo. :)

I thought of Star Wars first. :roflmao2:


Nice unit tho.

Where would you use this?

Where would you use this?

It was built originally built for use at Critical Mass rides.

After it was built, someone who works with our city's Transportation Planning Organization saw it, thought it was cool, and invited it to participate in some of the city sponsored group rides around the downtown area.

So far it has only been used for a couple 'test pulls'. This Friday will be it's first real use at a CM ride. It was invited to another city-sponsored ride this Saturday but we declined because the ride is primarily on greenways and we felt that loud music might not be appropriate for the confined space and would ruin the scenic beauty along the trail. We are hoping to bring it to some of the city sponsored rides later in the summer as they take place on (wider) city streets and tend to have more of a 'party' atmosphere.

That look pretty awsome...

Nice setup for the bike stereo! I remember seeing something similar (but not as custom or nice) where they had mounted the stereo amp, speakers, and battery in a small ice cooler for rain protection.

I have been using a stereo system I put together for CM or 'party rides'. I found a car stereo in a junkyard with input jack for an IPod. I power it with a 5 Ahr SLA battery (same as my lighting system). The stereo and battery are taped together and fit nicely inside a rear pannier. The speakers are old 8" bookshelf units I had around unused, and are mounted into homemade housings constructed of coroplast (http://www.coroplast.com/product.htm) signs I found littering the roadside ;). I attach the Ipod shuffle on my top tube with a Velcro strap. The speakers are temporarily mounted on the front and rear of the bike with a combination of Velcro straps and cargo bungee nets. It has played for over 2 hours without a problem. Good times!

Why not put a solar charger on it?

Solar trickle charger would be a nice capper to that project, great idea!

Only an hour? I mean, my stereo in my truck will run for SEVERAL hours, and it'll be hit or miss with it restarting... but no stereo problems. That's pushing 2 dash, 2 door, and 1 12in sub.

Is your 1 hr limit set by not draining the battery too much?

I fully intend to build a radio unit out of a bob style trailer. Something that I can keep semi-aero... cause it'll be pulling rythm duty on pace lines :D

It was built originally built for use at Critical Mass rides.

After it was built, someone who works with our city's Transportation Planning Organization saw it, thought it was cool, and invited it to participate in some of the city sponsored group rides around the downtown area.

So far it has only been used for a couple 'test pulls'. This Friday will be it's first real use at a CM ride. It was invited to another city-sponsored ride this Saturday but we declined because the ride is primarily on greenways and we felt that loud music might not be appropriate for the confined space and would ruin the scenic beauty along the trail. We are hoping to bring it to some of the city sponsored rides later in the summer as they take place on (wider) city streets and tend to have more of a 'party' atmosphere.

I was thinking "boy...your neighbors must LOVE when you ride to work every morning" but it's good to see that you use it for good and not evil. You could really annoy the hell out of everyone with that thing. Blare opera your whole way to work every morning or something...that'd be hillarious.

Pretty cool though, man.

Does anyone else find the car tire skid mark ending at the trailer in the first pic a bit funny?:D

Why not put a solar charger on it?

2 reasons this hasn't happened:

(a) No money.

(b) A solar charger couldn't come close to keeping up with the power demand on the battery when the stereo is running and the trailer is stored indoors when not in use so it wouldn't charge there either.


Only an hour? I mean, my stereo in my truck will run for SEVERAL hours, and it'll be hit or miss with it restarting... but no stereo problems. That's pushing 2 dash, 2 door, and 1 12in sub.

Is your 1 hr limit set by not draining the battery too much?

I fully intend to build a radio unit out of a bob style trailer. Something that I can keep semi-aero... cause it'll be pulling rhythm duty on pace lines :D

The 1hr limit was a guess because the 'calculation' for how many amps the stereo pulls and how quickly the battery discharges is so complex (many, many different factors at work including temperature, volume, gain settings, type of music, level of batteries original charge, etc.) that it was easier to just make a conservative estimate. You are correct though, since it's not a deep cycle battery it'll kill the battery to be fully discharged too many times and I'm sure Monika doesn't want to have her car jump started every single time she needs to drive someplace.

The trailer was awesome at the June CM ride. We rode all over town and got all kinds of waves and thumbs ups from cars and pedestrians. Even when we rode through a residential area folks were coming out of their houses to cheer us on. In the words of Borat, the trailer was "Great Success!"

I hope to have a video on YouTube soon.