Think of a cargo bike as a “dynamic triangle of mass.” It’s not abstract, it is kinetic ethics. This load balancing pyramid combines rider, cargo and vehicular mass. The center of gravity shifts uphill, downhill and when going into corners. We know triangles do not do well going into corners, “…a 2.50 m long john has a larger turning circle than a normal ebike and … most road users aren’t yet used to them.”
The physics of a “jacknifed” three wheeler, or two wheeler and trailer, moving at speed contradicts every glossy image of sleek, middle class, urban mobility. Put two unsecured children into the front of a bucket type cargo bike and you’ve built a pretty effective homemade catapult. Going downhill, the center of gravity shifts forward meaning you can cantilever yourself into the air with little effort on your part. “Cargo bikes require 40-60% more braking force than standard bikes. “
Put those same iconic children on the back and you cannot see them. Kids, being kids, do not have a high tolerance for comfortable commuting. Design choices to remove lateral support reduces mass, but rigidity is what delivers balance in sidewinds and on uneven road surfaces. Bike lanes are not usually built with “run off” or “clear zones” like those on high traffic motorway corridors.
Load balancing is key
In all designs, danger spikes under three conditions: Cornering with a top-heavy or side-loaded system The centrifugal force pulls the cargo away from the turn, risking tip-overs, worse if load is high or unsymmetrical. Downhill acceleration: A front-heavy design can pitch forward. Braking suddenly can cause an “endo” (over-the-bars scenario). Unrestrained passengers: If kids aren’t strapped in, they’re not just at risk, they’re the risk multiplier. They shift, they move, they destabilize while the rider is in motion. A sharp brake, momentum + gravity = disaster.
Design standards are emerging
Legislators are catching up (slowly). Countries like the Netherlands and Denmark have already begun forming safety protocols. DIN 79010:2020: A German national standard, defines requirements and “test methods for transport and cargo bicycles used to transport goods and persons.” European legislators are picking up the baton.
Child restraints to be mandatory in all family cargo bikes? Structural integrity testing for front-load boxes? Electric assist limited to 25 km/h (EU standard) for cargo vehicles? In Germany, there’s pressure for TÜV-like certifications for cargo bikes, especially commercial ones.
The question of load balancing and design…
We agree that having the load at the front or back of a cargo bike presents design and safety challenges. An optimum COG (center of gravity) for load and mass (low in the center) helps dynamic distribution of load forces while in motion and under braking forces.
This space is usually taken up with the mechanics of riding; batteries, motors, pedals and chain. New designs in chainless drives and electronic haptic controls moves the emphasis towards a reimagining of how a light urban vehicle might look, steer and move.
Expect to see a lot of movement in cargo bike, and more specifically e-cargo, design in the next few years. The overall concept is valid (a low “impact” cargo vehicle). The user base is enthusiastic. Applications are infinite. A 100 years of motorcycle design, suspension damping, wheel, hub, and braking knowledge, applies. We know where the issues are. It is a case of delivering the answers.
