A new phenomenon has emerged in the Netherlands: the skinnybike – the counterpart to the fatbike. Skinnybikes have tires that are up to six centimeters narrower than those of a fatbike.

Like fatbikes, they are theoretically electric bikes with pedal assistance up to 25 kilometers per hour. You therefore have to keep pedaling to move forward.

In practice, however, such bikes can easily be tuned to exceed the permitted speed of 25 kilometers per hour. The Dutch police recently took a modified ‘skinnybike’ with a top speed of 118 kilometers per hour off the road.

Tuned skinnybikes are often illegally modified with a throttle, meaning users no longer have to pedal. At that point, it is no longer an electric bicycle but a moped, and users must be at least 16 years old and have insurance.

Increasing accidents and theft

In the Netherlands, manufacturers are trying to use this to circumvent regulations on fat bikes. The latter already are a well-known phenomenon in the Netherlands, with increasing risks of accidents and theft. That’s why a growing number of insurance companies are imposing very stringent conditions for coverage or simply refusing to insure them.

Cities like Amsterdam and Enschede have banned the vehicles from the inner city. Fatbikes are not welcome everywhere in Belgium either – Hasselt has considered banning them – but in practice, it is difficult to ban bicycles based on tire width.

Belgian and Dutch law

In the meantime, the Dutch government has announced a broader approach and is preparing a helmet requirement from 2027 for under-18s riding all e-bikes and other light electric vehicles, precisely because making a watertight legal distinction between a fatbike and another e-bike has proven so problematic.

Belgian law also doesn’t recognize ‘fatbike’ or ‘skinnybike’ as legal categories, but it additionally has a category of ‘gemotoriseerde fiets’ (motorized bicycle) up to 1 kW and 25 km/h, subject to different requirements including a minimum age of 16 and a certificate of conformity.

But why are these vehicles so popular?

Fatbikes and skinnybikes (and conventional e-bikes) are basically the same: vehicles with 250 W maximum continuous motor power, and pedal assistance stopping at 25 km/h.

But apparently, the appeal of fatbikes – and now skinnybikes – is not just their looks or ease of modification. They’re also a low-cost alternative to the traditional European e-bike and, to some extent, to the electric moped.

In 2025, an average e-bike in the Netherlands cost €2,872, while the average fatbike cost just €1,198, or 58% less. Dutch electric scooter prices cluster around €2,000-€3,500, with faster models exceeding €4,000.

Those figures explain the youth appeal: for €700- €1,000, you get something that looks more like a small motorcycle or moped than a traditional bicycle, yet legally retains the privileges of a bicycle as long as it remains compliant. In the Netherlands, approximately 108,000 fatbikes were sold in 2025, accounting for roughly 14% of all new bicycles.

Belgium is nowhere near that level. The difference isn’t that Belgians dislike electric bicycles. They simply haven’t embraced the cheap, moped-style fatbike nearly as strongly as the Dutch have.

In Belgium, 578,737 bicycles were sold in 2025, and fatbikes accounted for just under 1% of the market, or ‘only’ 5,800. The Dutch fatbike market is therefore about 14 times larger in market share, and maybe close to twenty times larger in absolute numbers.

And where did they come from?

Modern fatbikes grew out of experiments in Alaska and New Mexico in the late 1980s and 1990s, when cyclists needed very wide tires to float over snow and soft sand. Later, they evolved into electrically assisted urban fatbikes and, finally, cheap, moped-style transport for young people.

The skinnybike itself appears to be essentially a Dutch phenomenon, born around 2024, developed in anticipation of legislation specifically targeting fatbikes.

Retailers openly sell them as alternatives to municipal fatbike restrictions. The sub-€1,000 electric vehicles show how quickly the industry can adapt products to remain within the legal definition of a bicycle.

What about enforcement?

The drive system of an e-bike differs from that of a moped, necessitating that police zones use suitable equipment, such as a modified dynamometer or a speed gun – a device that measures the speed of a moving vehicle. 

The Dutch police already use such dynamometers, and the Mechelen police zone borrowed one from the Netherlands earlier this year. The city of Ghent is also considering purchasing such a dynamometer to step up checks on illegal fatbikes and skinny bikes.