Note that some links in this question go to sites with a metered paywall, i.e. you can access something like 4-5 free articles per month. While the question mentions a bike manufacturer, the problem very likely spans all manufacturers of low-cost e-bikes.
Recently, Molly Steinsapir died while she and a friend were riding a cargo e-bike downhill. This was covered in mainstream and cycling media outlets, e.g. on Bicycling magazine's site. Her friend was unable to stop the bike, because the brakes did not engage. Why the brakes failed to engage during the accident sequence is not known. This Outside magazine article says that Molly's friend, who was controlling the bike, applied the front brake, but it didn't slow the bike and caused the wheel to wobble. As covered in both articles and this Tweet by cycling journalist Peter Flax, there may be widespread problems with the brakes on lower-cost cargo e-bikes. These may stem from any combination of the following:
- Cheaper disc brakes may generate less power
- This may be exacerbated by lower-quality cables and/or poor routing
- Low-quality brakes may come out of adjustment faster, wear faster, or otherwise be unreliable
- Novice consumers may not realize they should keep adjusting their brakes, or adjust them wrongly, or be dissuaded from taking them to a store repeatedly because of cost
For the record, cable (aka mechanical) disc brakes are specced on lower-end bikes because they're cheaper than hydraulic disc brakes. Hydraulic brakes self-adjust, and the system requires little maintenance if set up properly and the bike is in tolerance (e.g. disc brake mounts are flat). This Cyclingtips article after a 2022 bicycle field test argued that you could get good braking with cheaper mechanical disc brakes, although many bikes have low-quality cable housing or routing that robs braking power.
E-bikes in general are heavier and faster than unpowered bikes. This translates to more kinetic energy to dissipate while stopping. Cargo e-bikes are considerably heavier and can carry much more load than their peers. For the record, the Radpower model involved in the accident claimed a capacity for 300 lbs total weight. It has Tektro mechanical discs with 180mm rotors.
Question: What spec changes would suffice to ensure adequate stopping power on e-bikes? Would these raise the price of such bikes enough to affect demand?
Note that the original motivating issue was e-cargo bikes, which can carry significant loads. However, it seems warranted to discuss both cargo and non-cargo e-bikes if posters feel it's warranted.