There are many developmental bikes on the World Cup circuit, but none stand out quite as much as Reece Wilson’s Gamux Sego.
With its Pinion gearbox, Gates belt drive and bizarre backwards stem, there’s very little the Scottish rider isn’t willing to consider in the quest for speed.
We caught up with him at home to learn more about this intriguing setup and to try to understand some of the logic behind it.
Backwards stem
Glancing over the frame of the bike, the first thing that stands out is Wilson’s unusual cockpit setup.
The front of the bike sees the bar connected to a 25mm stem that has been flipped around and placed on rising plates.
Wilson says this gives -15 degrees of reach, and is something his motocross background convinced him to try.
The idea came to him after riding BMB’s Raised Reversed stem. Wilson says the setup makes the bike easier to ride, more akin to a motocross bike, where your hands are behind the steerer tube.
“I’m underqualified to explain it properly,” he says, “but something happens that fundamentally changes how the bike feels – and it’s a much better feel in my opinion.”
He also says the setup removes the need for a steering damper, resulting in less head shake and enabling a lighter grip on the bar.
While the stem is reversed, the stack height is raised high, enabling Wilson to stand up high on the bike.
Wilson says there has been some backlash towards the setup, with people claiming it's not possible to weight the front wheel up correctly, but he believes “this concept needs to be burnt and thrown out of the window”.
According to Wilson, he’s never had more traction, grip and front-end confidence.
All the adjustability
The Gamux Sego has been around for a little while, but it still turns heads as it thunders down the track.
It’s a design that focuses on adjustability, with every geometry and stiffness figure seemingly not set in stone.
While we’ve seen some teams testing rear-end stiffness, the Sego also enables Wilson to play with the torsional stiffness of the front triangle via bonded stiffening plates added to the frame.
The bike also gives Wilson the ability to change the chainstay length, pivot point, anti-squat and anti-rise characteristics.
You can even replace the link for more progressive or linear suspension setups.
This is important, with the bike currently using a Manitou Mara air shock to control the 197mm of travel, with Wilson alluding to an upcoming coil variant from the brand.
Up front, there’s a Manitou Dorado upside-down fork providing 200mm of travel.
We also caught a glimpse of what appears to be a prototype Dorado fork, which features a small tuned mass damper on each leg.
Pinion gearbox
At the centre of the bike is a Pinion C1.9 gearbox.
The system enables you to change gear without needing to pedal, which Wilson says enables him to enter a corner without having to think about setting up a gear for the exit.
The location of the gearbox also lowers the bike’s centre of gravity and reduces unsprung mass because there is no cassette or derailleur.
This should result in a bike that handles better and suspension that is more supple.
There’s also the benefit of not having a vulnerable derailleur hanging down where the rocks are.
A Gates belt drive is used in conjunction with the gearbox, which puts Wilson into the draw to win the £100,000 Belted Purse should he take the top step at a World Cup this year.
In order to protect the belt from sharp rocks, Wilson has created a small cover, which he has bolted to the bottom of the bike.
Tiny cranks
Connected to the Pinion gearbox, Wilson has been experimenting with shorter cranks.
Unlike the trend in road cycling, Wilson isn’t using them for aerodynamics, reduced knee and hip strain or higher cadence efficiency.
His logic for using shorter cranks, sometimes as small as 100mm, stems from a desire for symmetry on the bike.
He explains that sports in which you move forward with your legs together, including motocross, horseriding and skiing, require your feet to be side-by-side – but mountain biking doesn't.
NSB has created a set of custom-length cranks for Wilson, ranging from 100mm to 140mm, enabling him to play with the concept.
He says the gain has been noticeable, with turns against his forward, dominant foot feeling more balanced.
