Pedal Power Generators
You will need enough bicycle generators that the pedaling effort per person is approx. 50-75 Watts. Based on our experience at events, 50-75 Watts is the amount that an average audience member can continuously provide. You should also have ‘ringer pedalers’ in your crew. Ringer pedalers are strong racer or everyday commuting cyclists who can contribute up to 4 times more than an average pedaler. Whether you’re relying on ringers or the GP (General Public), you’ll need to provide enough bikes that the effort can be shared.
In order to make Pedal Power fun and inspiring, your goal should be to have the lowest ‘overhead’ possible. Overhead is how much Wattage your system draws when no music is playing. Using energy intensive devices like rack-mount audio gear, subwoofers, large guitar and bass amps, laptops, and lights can add significant Wattage to your system’s overhead. If you already know what devices you want to run, start by measuring their Wattage with a Kill-A-Watt. Having a lower overhead means that more of your pedalers’ energy goes into music, not keeping devices on.
If you are planning to use our Modified JBL PRX Loudspeakers, you can follow this table to estimate the crowd size possible for a given number of pedalers. These numbers are for danceable levels of music and assume a favorable overhead.
|Number of Pedalers||Estimated Crowd Size Possible in an Outdoor Location|
|1||200-500 (with One Bike / One Speaker)|
|20||2000+ We haven’t had enough chances to test at these power levels.|
What kind of generator?
The most effective generators are hub generators. They are efficient, quiet, and can convert a huge flow of power if the pedaler is cranking hard. The less effective ones are friction generators (tire rubbers). We recommend only hub generators, though for people on a long-distance bike tour, the extra weight is a drawback. Using efficient, quiet generators is better because it makes Pedal Power feel more impressive, which makes people want to pedal more, which in turn makes them want to ride bikes well after your event. Check out this page to see all of our generator options: the Mundo 500 (electric version of our favorite cargo bike), the Electric Fender Blender Pro (towable bike blender and generator), and generator wheels to turn any bike into a generator.
Do not bother with Hi-Fi equipment (including home theater, bookshelf speakers, and computer speakers) or car audio gear. Neither of these were designed for large spaces and large crowds. If your goal is to produce an outdoor music event, you need to use “Pro Sound” equipment that was designed to reach larch crowds at events.
We sell Modified JBL PRX Loudspeakers. We modify and sell the full line of JBL PRX speakers, from the smallest wedge monitor (the PRX 612) to the 1000-watt subwoofer, the PRX 618. The ‘modified’ part means that we hack the circuit boards to allow them to run on DC power, bypassing the need for AC power (wall power). Since the conversion of Pedal Power from DC to AC and then back to DC inside the amplifier is wasteful, our Modified JBL PRX loudspeakers run 43% more efficiently than in AC mode. PRX loudspeakers are already some of the most efficient powered speakers commercially available, thanks to their Crown digital amplifier, so the additional power savings in DC mode makes them (quite possibly) the most efficient Pro Sound loudspeakers in the world! They make Pedal Power feel truly impressive. Pedalers have a big smile on their face when they hear how much powerful, crisp sound results from their good clean Pedal Power. This is a Rock The Bike exclusive offering.
PRX speakers are made of high quality plywood and have a durable coating. Although they’re heavier than some plastic speakers, they are relatively lightweight for Pro Audio gear, making them manageable to get to and from events by bike.
What ever loudspeakers you use, don’t forget the importance of proper elevation and positioning of the loudspeakers. Pro-sound speakers like the ones we sell at Rock The Bike have scientifically calculated dispersion cones that help the sound spread out to the sides. In order for these dispersion cones to do their work, your speakers have to be up in the air on a speaker stand.
Generally you need at least two mains to do an event. But we know from experience that with 1 speaker, good music, and Pedal Power, people will dance. Generally speaking, divide the anticipated size of the audience by 100 to get the correct number of mains. This is only applicable for events up to 500 people. Beyond 500 people, using speakers on stands is not going to cut it. You need to start thinking about elevating the speakers even further, using subwoofers, and considering a Line Array configuration.
What about monitor speakers?
Monitor speakers are how the bands hears themselves during performances. Very few musicians can perform at their best without monitors. Generally you need 1 monitor for every 2 bandmembers of a full band. At least 2 for most bands. For public speaking events like a press conference, you can do without them. We sell the Modified JBL PRX 612 wedge monitor.
What about the speakers you already have?
You may already own certain Pro-sound gear or have musician friends who have gear. Can you just plug that in and roll with it? Basically, the answer is yes, but you may pay a significant penalty in both weight and efficiency with older PA gear. Many newer powered speakers have digital amplifiers. These generate less heat and therefore require less power/fewer pedalers. How can you tell if your speaker has a digital amplifier? Look up the model number online, or measure the wattage of your speaker using a Kill-A-Watt.
Can bands still use their own amplifiers?
Musicians are used to playing their guitar, bass, and sometimes keyboard through a specific amplifier. The amp is part of their instrument, part of their sound. Unfortunately, their amp increases your overhead. Ideally you will have enough bicycle generators that the extra wattage of their amplifier doesn’t matter. Asking a musician not to use their own amp is an unusual request. However in our experience, we get great results asking bass players to ‘go direct’ or play through the PA. This means that the bass player leaves her amp at home, and plugs the bass into a channel on our mixer, just like the lead singer. There’s still plenty of bass but there are fewer devices ON and therefore lower overhead. If you have a small Pedal Powered Stage with, say, 3-5 pedalers, you may not have enough raw power to keep additional devices on besides the bare essentials (the mains, a monitor, and the mixer). Fortunately, the bass players we’ve worked with are very happy with the sound they get at our events.
Pedal Power Utility Box, i.e. the Circuit
The Pedal Power Utility Box contains the AC Power inverter, a capacitor that holds a few minutes worth of power, the protection circuitry that keeps the system safe from overvoltage conditions, and outputs for your DC-powered devices (like the loudspeakers mentioned above). Our Utility Boxes now include a 4-line Pedalometer in the lid that shows pedalers how hard to pedal. Even if you buy our Modified JBL PRX Loudspeakers, which run on DC power, you will still need AC power for devices like guitar pedals, amps, mixer, etc. All this functionality is protected inside a durable red plastic toolbox with a sturdy handle and latches. Your circuit takes Pedal Power in and kicks out a steady stream of regulated, usable power to the audio equipment and devices. The simplest type of output power is traditional AC power; this means you will be using a DC-AC inverter. But in our Split-Rail Utility Boxes, there are special outputs for Split Rail Power required by our Modified JBL PRX speakers.
Can you store the energy created?
The circuit also includes whatever storage method you are planning to use. We use 30V Ultracapacitor ‘bricks’, which hold just enough power for a few minutes of music.
Why do I need protection circuitry and what type do I need?
The microprocessor brain in our Pedal Power Utility Boxes monitors the key system voltages and triggers relays that disconnect the pedalers from the system to prevent overheating and damaging the devices you’re running, or the Ultracapacitors. In addition to overvoltage protection, you also need fuses in case of short circuits. The input cables that connect the bikes to the system are long and are often subject to harsh conditions: people walking on them, tripping over them. Of course, you should tie these down as well as you can with reuasable Velcro ties. But you should also install fuses that prevent a bad yank from causing a meltdown. The circuit itself needs to be protected. We use Tupperware inside the box to prevent our microprocessor brain touching anything else and accidentally shorting. Your circuitry can’t be out in the open where it can be damaged in transit or where a metal wrench can be set down on it, causing a short circuit.
In a bicycle based system, any wire can be tugged or rub against a tire and degrade from wear. They need to be ‘strain reliefed’ and insulated. Connections from bikes to the circuit need to be both quick-connect for ease of setup and robust. We use Neutrik connectors, the industry standard for Live Sound.
Our current pricing structure is that most of your wiring is built in to the price of the other components. For example, if you buy a generator, you get an input cable. If you buy a speaker, you get a speaker power cable. We use only 14AWG gauge wiring for power cables that will see the outside world.
You will need a way to show Pedalers how hard to pedal. Otherwise they may drift off in their thoughts (and power output) or overpedal your system.
The ideal Pedalometer is the classic thermometer style, because it’s intuitive, making it possible for pedalers to get lost in the music while still providing the exact amount of Pedal Power needed. The pedalometer uses color-coding to show the pedalers when they need to pedal harder and when they need to slow down. Just keep it in the green.
The voltage information shown on the Pedalometer is also important to the sound guy/girl, who can raise and lower the overall listening levels and the bass levels according to the available system power. The Pedalometer also engages the audience in the Pedal Power experience. Even the bands get involved. When they see power levels dipping, they may make a funny comment about it between songs to help pedalers boost it back up.
Pedalers need to be coached. There are two essential aspects to doing this: the human touch, and accurate, up-to-the-second information about the system voltage.
Food is the fuel for a Pedal Powered event. Offer pedalers a free bike blended smoothie and they’ll have the juice to keep providing their good clean Pedal Power.
Check out all the options for Bike Blenders in the Fender Blender section of our store. Bike Blenders also make a good fundraiser for your cause. Keep plenty of water on hand too!