eDirtysixer w/ Bosch Smart System: Sometimes Size Does Matter

Tall people face numerous challenges in everyday life. After all, we have designed large parts of our world according to average sizes. Among other things, this applies to ebikes. Accordingly, it is difficult for anyone with a body length of two metres or more to find a model that fits their height. A small company with a US background discovered this niche for itself more than ten years ago. Now it wants to launch the largest ebikes ever built in series on the market.

eDirtysixer featuring 32-inch wheels (right) and 36-inch wheels

It all starts with a fall

Like many company foundations, that of Dirtysixer can be traced back to a personal anecdote. Founder David Folch, himself 198 centimetres tall, once had a fall on a bike that was only subsequently adapted to his body size. According to him, this was because the bike simply couldn’t cope with his height. With some of his limbs in plaster, Folch was condemned to an enforced break and, while lying in bed, began to think about what a better bike for tall people might look like.

That was in 2011. Now, it’s 2024. David Folch has long since turned his musings into action, founded Dirtysixer and is currently raising money via a crowdfunding campaign. He wants to use the additional funds to expand his range with the eDirtySixer. The ebike incorporates the experience of around a decade of building a specialised bike – together with an ebike system from Bosch’s Smart System. The former is particularly important for the qualities of this ebike. Especially as the huge wheels immediately catch the eye. They are the decisive clou of the Dirtysixer.

The proportions have to be right

Taller people have a higher centre of gravity than shorter people. Bikes with maximum 29-inch wheels can only compensate for this to a limited extent. This results in disadvantages in terms of balance and stability while riding. Wheels whose size increases in proportion to the rider’s height can resolve this imbalance. They provide a much safer riding experience. Folch has therefore been using 32-inch and 36-inch wheels for years. And with second number you even know where the origin of the brand name does come from.

However, safety is only one advantage of the huge wheels. For tall people, pedalling such a bike requires less effort. They make more efficient progress and tire more slowly. And all of a sudden, cycling becomes a pleasure. Especially as the frame of the eDirtysixer keeps pace with the wheels and also exceeds the usual dimensions. This puts bikers in a riding position whose ergonomics match their measurements, so that neuralgic points such as the back, neck and shoulders are effectively relieved.

If it suddenly gets completely dark on the bike lane next to you, it could be because someone on a bike with 36-inch wheels is about to overtake you.

What does ‘large’ mean?

To give you a better idea of the spheres in which the four frame sizes of the eDirtysixer operate, we have taken a look at the geometry of the version of the bike that does without the motor. There is currently no geometry of the ebike on the manufacturer’s website. However, there will probably not be any major differences between the two versions.

Visually, the oversized, enormously voluminous top tube quickly catches the eye. Its distance to the seat tube, i.e. the effective top tube length, is between 606 millimetres and 770 millimetres. The seat tube itself measures between 540 millimetres and 620 millimetres. To ensure that the wheels are adequately supported by the frame, the chainstays need to be 570 millimetres long. The resulting wheelbase is between 1,286 millimetres and 1,407 millimetres. Remember, the wheelbase – not the overall length! In the smallest frame size, a single XL, the manufacturer uses cranks with a length of 175 millimetres. For the largest frame size, a quad XL, the length is 200 millimetres. The pedals mounted on the cranks measure 160 millimetres x 110 millimetres.

If Shaquille O’Neal wants to ride a bike with a shoe size of about an European 60, the pedals can be a little bigger.

Material mix for the tall ones and the really tall ones

The slogan ‘Bigger is better’ appears under the Dirtysixer logo. Whereby Dirtysixer makes very specific gradations. The XL and 2XL frame sizes are based on the 32-inch wheels. Only the 3XL and 4XL sizes are intended for 36-inch wheels. In terms of body length, this means that the manufacturer covers a range from 1.78 metres to 2.27 metres with the eDirtysixer.

There are no special details on the frame itself that can be attributed to its use by tall people. The aluminium construction works with a steeply sloping top tube. A small additional strut leads from this to the upper end of the seat tube to further stabilise this area of the frame. There are mounting points on the steel fork for attaching carriers and mudguards. Dirtysixer also offers a rear carrier developed in-house as an accessory.

T-Monster tyres from Vee are used on the eDirtysixer.

Trust in the market leaders

The drive mentioned at the beginning features a Bosch Performance Line CX in combination with Bosch’s largest intube battery, the PowerTube750. In terms of both motor performance and battery capacity, this appears to be a good match. For operation, the eDirtysixer relies on the combination of the Bosch Mini Remote on the handlebars and the System Controller integrated in the top tube. A Kiox 300 can also be seen in the pictures shown in advance. However, it remains to be seen whether this will be part of the standard equipment.

The manufacturer uses a mechanical derailleur system from Shimano for the actual drive. The Cues groupset offers ten gears. It is installed in the Linkglide version specially designed for use on ebikes. The braking system also deserves special attention. With the target group in mind, this has been upgraded with two brake discs on the front wheel. Their diameter is expected to be the familiar 203 millimetres. The increased braking force should ensure that the taller and therefore usually heavier riders can brake reliably and in a controlled manner at all times. Anyone who knows that Shaquille O’Neal is one of Dirtysixer’s customers will have an idea of what the task is. In his active days, the NBA superstar probably weighed around 156 kilograms. In retirement, he probably weighs a few more today.

Better safe than sorry. This should absolutely apply to the brakes on the front wheel.

Superstars go for Dirtysixer

Speaking of basketball and the NBA. David Folch and his bikes seem to have more fans among the players. Frenchman Rody Gobert, for example, who was voted the best defensive player in the entire league for the fourth time in his career a few days ago, is said to have ordered 15 of these bikes during his time with the Utah Jazz. As a gift for his team. And Dirk Nowitzki is also rumoured to own one of the brand’s bikes. For Dirtysixer’s marketing, such customers should be worth their weight in gold, especially on the US market.

Nevertheless, you can be ahead of these superstars. After all, they are probably not yet riding the eDirtysixer with electric assistance. If the necessary money is raised with the help of the crowdfunding campaign, the production model will later cost 8,999 US dollars. However, shipping costs to Europe would still have to be added.

eDirtysixer at a glance

• Frame: Aluminium
• Fork: CroMo
• Motor: Bosch Performance Line CX
• Battery: Bosch PowerTube750
• Control unit: Bosch Mini Remote & Bosch System Controller
• Drivetrain: Shimano Cues Linkglide
• Brakes: Tektro, hydraulic, 4 brake pistons, double rotor on the front wheel, 203 mm
• Maximum permitted total weight: n.a.
• Price: expected to be 8,999 US dollars

Pictures: BWB dba DirtySixer