Big Wheels: Design Logic’s workhorse Phat Bikes are for more than just work

For Lance Portnoff, research and development doesn’t happen in a laboratory or a tech facility. The Fairmount-based bike designer prefers to do his research on two wheels, pushing himself against his closest competitors.

In 2010, he entered the Motor Assisted Bike Death Race in Tucson, Arizona on a cargo bike he had designed himself. He placed ninth out of 50 contestants in the race, and further developed that prototype using what he’d learned during the race. Soon after, Portnoff earned a patent for the design of his retooled bike, which was shortened, stiffened, braced and tuned from the racing prototype. He christened the bike “Da-Bomb,” and it served as the foundation of his new company, Design Logic. “Racing, you learn what works and what doesn’t, what breaks and what holds up,” Portnoff says. “It’s a starting point to figure out what’s going to eventually work in the real world.”

Da-Bomb was followed by Da-Trail, a shorter wheelbase model, and earlier this year, Portnoff unveiled Da-Phat, which boasts 4.8-inch thick tires. “The ‘fat’ style of bicycle has been out for a couple of years now,” Portnoff says. “There are one or two manufacturers that make them, but there isn’t one that’s specifically a cargo version. The value behind these bikes is basically being able to ride on snow or sand. A regular bike doesn’t have a big enough tire with enough flotation to get over those types of really soft obstacles.”

Design Logic’s bikes are equipped with a built-in rack on the rear of the frame capable of carrying up to 150 pounds. It is available with a removable Da-Hitch attachment that allows the rider to tow a small utility trailer. Portnoff has used the trailer to pull loads of up to 200 pounds. The company now offers a trailer specifically for the bikes dubbed, naturally, Da-Trailer.

“I’ve always ridden bikes, and I have a background of working in the industry,” Portnoff says. A lifelong cyclist, he began working in bike shops and racing during high school. After graduating, he attended welding school and worked with frame-builders and mechanics to learn the basics of bike manufacturing. The company is currently a two-man operation, with Portnoff supplying the designs for a builder who crafts the bikes’ frames. “I’m basically in the process of building a brand from an idea,” he says.

He describes Design Logic’s bikes as “a utilitarian design. It’s heavy-duty; it basically serves a purpose. Most bikes just don’t have the capacity to tow a trailer or carry a heavy load on the frame itself. So, we basically want to make a product that’s usable, that’s not just like any other bike.”

Portnoff sees the company’s future in supplying bikes to the shipping industry. “It’s a usable viable product that industry can use,” he says. “FedEx can use it, UPS could potentially use it. That’s where we’re going: down the avenue of a commercial end-user.”

That’s not to say that Portnoff discourages private consumers from using the bikes. The company’s website proclaims, “our bikes give you all the comfort and health benefits of a regular bicycle, while allowing you to tow things like groceries or packages.” As for the new Da-Phat model, its symmetrical rear triangle allows the fat 4.8-inch tires to be swapped out for 29-inch mountain bike wheels, for more day-to-day riding when terrain isn’t quite so challenging.

All of Design Logic’s bikes feature a range of available colors and a 20-inch frame capable of carrying a rider measuring 5’5” to 6’4”. The Da-Bomb model’s longer wheelbase makes it roughly the size of a tandem bike, and is less of a focus for the company these days than its two siblings. That shift has to do both with Da-Bomb’s more cumbersome size — which essentially requires garage space for storage — and the fact that it is built with the installation of a gas-powered engine in mind. The company’s later models reflect its move to the use of electric motors.

Design Logic builds the bikes in both motorized and non-motorized versions. The built-in electric motors, which add about 30 pounds to the frame with batteries included, can handle speeds up to 50 miles per hour, at least 10 miles per hour faster than the legal speed limit in any U.S. state. But Portnoff envisions a future for Design Logic bikes beyond utilitarian consumers and street-legal consumer transportation. He’s itching to get back into racing, and is organizing an electric bike racing team.

“I’d like to see Red Bull-sponsored events,” he says, “to see it be considered an extreme sport.”


Story by Shaun Brady | Photos by Chris Sembrot