Thanks to the Bike Auckland member who pulled together the research for this article. The opinions shared here represent their views and are intended as food for thought in the growing debate around micromobility devices. They are not intended to represent any official position of Bike Auckland.
Recent news headlines from both here and around the world have highlighted concerns around what we are going to call e-motos. These are not e-bikes as we know them, they are high powered, dedicated electric offroad motorbikes. The only similarity between an e-bike and an e-moto is pretty much the number of wheels and a battery.
E-motos will often be sold with a tiny sticker on them saying “Offroad Use Only” (or no sticker at all), but of course many end up being purchased and used on our cycleways, shared paths and roads. I don’t take issue with e-motos being sold for use on motocross tracks, designated forestry roads, dedicated offroad motorbike parks or farms. However, in my view, the illegal use of these e-motos being used on our shared paths, cycleways and streets is becoming an issue for everyone.
As with all new technology, legislation and enforcement is slow to catch up. Our laws are outdated and don’t reflect the range of micromobility devices many of us use today.
Limited enforcement of the current laws has seen enough tolerance of e-motos that people are willing to take the risk of buying one – many buyers may be ignorant of what the law actually allows. There is a risk that a high profile accident will result in a knee-jerk change of legislation that would negatively impact everyone on an e-bike.
Online today you can purchase 750 Watt e-moto for “city explorers and off-road adventurers”, capable of 55 km/h, for around $2,000. It does have pedals, but it has more than double the power to meet the legal definition of an e-bike. Nowhere in the advertising does it say it is illegal to use on a cycle path and needs to be registered as a moped.
For around $2,500 you can pick up a 2,000 Watt, 64 km/h mini-dirt bike where the advertising blurb says: “Ready to pull off wheelies, turn heads, and own the streets? Let’s go!”. You may be able to “Own the streets” if you get it registered as a moped, but it is not legal to use on a cycle path.
Stepping up again,the E-Ride mini for $5,895 gives you 6 kW (6,000 Watts) on tap and weighs close to 50kg. That’s twenty times the maximum power in the legal definition of an e-bike and around double the weight.
At the top of the range you can find e-motos with 30 kW or more. That’s one hundred times the power in the legal definition of an e-bike. In the right setting, these bikes are amazing high-performance machines. But being ridden on our streets and paths by inexperienced, often underage, unlicensed kids, they are a potentially lethal weapon.
Confusing the matter slightly that some e-motos have lights, indicators and all the safety features that allow them to be registered and ridden on the road. They are just not to be ridden on a shared path or cycle paths.
In my opinion, the retailers of these bikes should be made responsible to explain to customers the exact legal status of the bike and the fines involved if they are ridden illegally. Once people are used to using these things, it is much harder to remove their perceived entitlement to use them, than if they had been clearly told their limitations at the point of sale.
Other e-vehicles
The NZTA website has all the regulations for e-bikes, and low-powered vehicles. Here’s a summary of what is the maximum power for each type.
E-scooters should have a maximum power of 300 Watts. That’s the output of a Flamingo or Lime scooter. However you can buy high performance models with 1500 W peak power and a maximum speed of 120 km/h.
E-skateboards are a bit of a grey area but probably fall into the NZTA mximum 300 watt limit. However, some are advertised as having 2 x 3.5 kW motors and these larger motors are capable of speeds up to 50 km/h.
A Segway Ninebot scooter is advertised as having 2 x 800 Watt motors and a top speed of 20 km/h.
In a similar vein, the self-balancing single “e-wheel” or e-unicycle devices can have a 4.2 kW motor and top speeds of 40 km/h.
The NZTA would look at these as not being permitted on shared paths or cycleways.
An exception to the 300 watt restriction are mobility scooters, which are legally allowed to have up to a 1500 watt motor and are usually limited to 12-15 km/h.
Most of these scooters, skateboards and other devices are used responsibly and safely on our paths and at speeds that are not inherently dangerous. After all, we have many cars driving around our streets with staggering amounts of horsepower on tap. However, one serious accident could change attitudes overnight. The ‘share with care’ message should be reiterated frequently, but in my opinion, there should also be a big stick available for flagrant irresponsibility.
What’s in a Watt?
You’ll hear the term Watt whenever you’re talking about how powerful electric bikes and scooters are, so let’s look at what is a Watt?
In simple terms, a Watt is a measure of power. In physics terms it’s the equivalent of one joule of energy per second (no, please don’t glaze over, that’s pretty much all the physics you’re going to get). To put it in a real-life context, an old-fashioned domestic lightbulb took around 100 Watts* to light up a room and an electric heater used about 2,000 Watts on full power.
A bicycle is an incredibly efficient machine. Riding a bike slowly on a flat surface requires very little energy, it takes around 12 Watts** to travel at 5 km/h (walking takes about 100 Watts). Some of that power is taken by friction from the drive train and your wheels rolling along, the rest is wind resistance. As your speed increases, the power required to overcome wind resistance goes up exponentially. To do 20 km/h the power required increases to 88 Watts and to do 30 km/h takes 215 Watts. You can see why a headwind slows you down so much and why time trial cyclists spend so much attention to aerodynamics.
As the terrain heads upwards, more power is also needed. Even an imperceptible increase in gradient will slow you down or require more power to maintain your speed. This leads to the term “false flat” where the road feels flat but you feel like you’re pedalling harder to maintain speed. At a four percent gradient** (typically the steepest sections on a rail trail) your 20 Watts on the flat becomes 125 Watts to maintain 20km/h. At eight percent, it almost doubles to 230 Watts. In effect you are lifting yourself and your bike vertically using a ramp. The more you or your bike weighs, the more energy it takes to do it. You could pedal slower and use less energy over a longer time (remember the physics lesson at the beginning). Or you could also lose weight or get a lighter bike, but there’s no getting over the fact that getting up hills requires a lot more power than riding on the flat.
The big advantage of an e-bike is that a motor can reduce the human power required to overcome headwinds and hills. You will still need to provide some effort, but you won’t end up dripping with sweat and legs screaming at the top. Many bikes have a cutout that reduces power output at a set speed (a legal requirement in some countries). However, even ones without a speed limiter, riding at 35 km/h will typically use all the e-bike’s Watts!
*Energy efficient lightbulbs use about 12-15 Watts for the same light output as a 100 Watt incandescent bulb which turns a lot of its power into heat.
**Power required varies with road surface (smooth or rough), tyre type (slick or nobbly), whether you’re sitting upright or in an aerodynamic position and how well your drive train is maintained.
*** Gradient is measured in % as the ratio of vertical movement divided by horizontal movement. A 4% gradient is a rise of 1 metre over 25 metres.
Thanks to https://www.omnicalculator.com/sports/cycling-wattage for the calculator.
