Meet the Boom Bike: Portland’s rocking, rolling, pedal-powered soundstage

A clean energy advocate, bike lover, and fabricator in northeast Portland has launched something that will change Portland streets forever: the Boom Bike — a 100% human-powered mobile soundstage, pedaled behind a trike that can carry 500 pounds of cargo and broadcast live music to a massive audience.

Cully neighborhood resident Mike Cobb built the Boom Bike based on a design by Xtracycle co-founder and carfree musician Kipchoge Spencer. Cobb is no stranger to pedal-powered projects as you might recall his role as an organizer of the Disaster Relief Trials or how he hooked up pedal-powered generators for Dakota Access Pipeline protestors at the Standing Rock Reservation in 2016.

I got an up-close look at the Boom Bike during a visit to Cobb’s workshop last week.

Cobb has known Spencer for years and once worked as a mechanic on his global, bicycle-powered Pleasant Revolution music tour back in 2010. Cobb reconnected with Spencer in 2020 to build five Boom Bikes as part of a massive parade in support of Bernie Sanders’ presidential campaign.

Cobb says his latest creation is, “The pinnacle of bicycle powered sound.”

The heavy-duty Coaster Cycles trike has a custom cargo bed that serves as a platform for the stage. Bolted to the stage is an off-the-shelf, Rock The Bike blender generator that can generate up to 100 watts at 120 volts — plenty to power the JBL loudspeaker and various electronic components that allow the music magic to happen.

Very low gearing allows Cobb (or whoever else operates it) to pedal relatively easily at slow speeds on a flat surface. Note that the Boom Bike does not use electric battery power — all the power is generated by the person who pedals right behind the trike operator. If hills are on the route, Cobb will call up two additional team members who will ride skateboards alongside and then quickly stow the boards on-stage while they push from behind.

Mike Cobb (foreground), Rachel Freifelder and Dan Kaufman.

While almost anyone produce the 50 watts needed to power the speaker, and most regular bike riders can easily create the 100 watts for full power, driving the trike will take more strength and skill. To help with that task, Cobb designed a handlebar with multiple leverage points and holding options for maximum rider input and comfort.

Dan Kaufman (of Disco Trike fame) is a local musician and friend of Cobb. To get on the stage where he sings, and plays his harmonica and guitar, Kaufman must walk up a ladder. Then he leans on a backrest and straps in with a sturdy buckle, similar to the set-up on a parade float. Once his helmet is on and wireless mic is in position, he’s ready to go.

“It was a bit off-putting at first because you’re pretty high up,” Kaufman said. “But I think a lot of performers are going to want to get on the back of this once they see how cool it is.”

Kaufman and Cobb are eager to try the Boom Bike at events like Sunday Parkways, protest marches and bike bus rides. They’re working on hooking up to an FM transmitter so other people can link up on a group ride for even more sound.

Rachel Freifelder, another Boom Bike team member who lives nearby and has known Cobb for many years, said she loves it because it helps her feel like a kid again and is a beautiful demonstration of the potential of bicycles. “My whole life I’ve been hearing people say, ‘Oh, but you need a car so you can do this or that,’ buit I think this is just such a beautiful example of things you can do with a bike.”

“And when we did our trial run last week and we’re riding around the neighborhood,” Freifelder continued. “I just couldn’t stop smiling when I saw how many neighbors we were making smile. And people in cars who are like, ‘Whoa, that’s amazing!'”

Watch for the Boom Bike at Portland bike events soon!

Jonathan Maus (Publisher/Editor)

Jonathan Maus (Publisher/Editor)

Founder of BikePortland (in 2005). Father of three. North Portlander. Basketball lover. Car owner and driver. If you have questions or feedback about this site or my work, feel free to contact me at @jonathan_maus on Twitter, via email at, or phone/text at 503-706-8804. Also, if you read and appreciate this site, please become a supporter.

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4 months ago

Hurray for pedal power! Hurray for Mike Cobb!

Beth H
4 months ago

If this were any more fun, it would need a license. Brilliant!

surly ogre
surly ogre
4 months ago

Fantastically, Fabulous!!

Wake Gregg
Wake Gregg
3 months ago

All sorts of Suess-like awesomeness! How far out is the jack standed lower bike charging accessory?