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Meet the maker: DirtySixer

How do you find a bike that fits when you’re a 7-foot basketball player? You look to DirtySixer, the bike for super-tall riders

Jonathan Manning
13 Jul 2022

Any adult who has ever nipped into the toilets of a primary school will know the unsettling feeling of being a giant. Everything looks familiar, but in miniature; the toilet bowls reach mid-shin and the basins are knee-level.

Now imagine living life like this, as a modern-day Gulliver in a Lilliput world, where sitting on a plane requires leg origami and doorframes demand a limbo dance. As for finding a bike that fits… forget it.

At 6ft 6in tall, David Folch was all too aware of these problems. The 47-year-old Frenchman, based in the USA, spent years trying to build a bike to suit his lanky frame without success. Extending tube lengths led to ‘scaffolding’ projects that perched him high over the rear hub, ruining his weight distribution.

The bikes were unstable and uncomfortable no matter what changes he made to the stem, seatpost or cranks. As Folch says, if you start with salty coffee, it doesn’t matter how many teaspoons of sugar you add, you still have salty coffee.

Eventually something had to give, and it turned out to be his ankle, smashed in a crash a decade ago. During rehab, a friend told Folch about a handful of mountain bike builders who were exploring the possibilities of 36-inch wheels, originally designed for unicycles.

Quizzing these framebuilders confirmed Folch’s belief that bigger frames require longer wheelbases to shift the rider’s weight towards the centre of the bike.

‘Look at the Eiffel Tower – if you build higher, you have to have wider foundations,’ he says.

Size matters

A few minutes of Photoshop proved Folch’s point. Scaling up a photograph of a 5ft 8in rider until he was 6ft 6in stretched the wheels to 34-35 inches. When he continued to 6ft 11in, the wheels reached 36 inches.

‘As kids grow we move them up from 16 to 18 to 20-inch wheels, so why do we stop at 29ers or 700c when the human body grows taller than 6ft 4?’ he asks.

Answering his own question, he says the reason lies in the standard lengths of chainstays and seatstays available to framebuilders. These tubes can be cut down for bespoke perfection, but not lengthened. Tooling up to make stays for 36in wheels was too costly and complicated, leaving Folch struggling to find a framebuilder able to fabricate his CAD-drawn hardtail mountain bike.

In 2012 he finally found a builder, but by his own admission the bike was not a success. Weight weenies look away now – made from 4130 steel, the down tube alone weighed almost 3kg.

A follow-up titanium frame was more promising, and Folch took it to Ventana, a company that hand-builds bikes in California, to commission a small production run. Ventana, in turn, made a few revisions to the geometry before making the first bikes from 6061 aluminium with chromoly forks.

More iterations followed, until in 2016 Folch launched a crowdfunding campaign, securing 50 orders for his rigid fork AllRoad mountain bike, the DirtySixer Mark I (the name stems from Folch’s pronunciation of 36er in a French accent). The Ventana-made bikes came in three sizes: XXXL for 6ft 5in to 6ft 9in riders; XXXXL for 6ft 9in to 7ft 1in riders, and XXXXXL for 7ft 1in to 7ft 4in riders. At 5XL the top tube measures 780mm. 

Hoop dreams

It didn’t take a genius to realise that a key audience for these huge bikes might be pro basketball players. First to show an interest was former Portland Trail Blazers centre Bill Walton – all 6ft 11 of him. Walton introduced DirtySixer to the National Basketball Retired Players Association, whose members took to the bikes with glee.

Shaquille O’Neal (7ft 1in) was the first customer, riding away on a nickel-plated DirtySixer, and 7ft 4in Mark Eaton was so keen he pedalled a prototype around a hotel with a smile as wide as his wingspan. Eaton introduced Folch to 7ft 1in Rudy Gobert of the Utah Jazz, who promptly ordered a DirtySixer for himself, along with 16 more – one for each of his teammates.

Even the legendary Lebron James has a custom-made DirtySixer, pimped with Archer electronic shifting and carbon fibre rims.

Their testimonies chime with those of every DirtySixer customer, delighted to rekindle a joy of cycling denied to them since they outgrew standard bikes in their teens. One customer emailed Folch recently to say he had just clocked up 8,000 miles, slimming down from 28.5 stone to 20 stone in the process.

So what are the bikes like to ride? They’re built for comfort not racing, says Folch, suggesting the Mark II weighs about 16kg. It was never going to be lightweight when bar grips need to suit hands that can wrap a good way around a basketball, pedals have to accommodate size 15 feet and brakes need to be able to stop a 25-stone rider.

However, lighter wheels are on the way, and the future looks to include electric assist versions of the AllRoad, and a mountain bike. It’s all part of Folch’s ongoing quest to make the
‘best solution for tall riders’.