After seeing Harriet Harnden finish first in qualies in Korea, then 4th overall in the DH finals, we started digging into her AON Racing Gates belt-drive bike setup, quickly finding these prototype Gamux gearbox downhill bikes under the three men on her team. Completely CNC-machined with a single massive open U-shaped frame member, it’s one of the wildest race bikes we’ve seen – beyond the high-pivot, gearbox & belt-drive setup.
Plus, the AON Racing team are hiding a lot of unreleased kit on these gravity sleds. New fork & shock tech, new brakes, new grips, wild stems, and more! Let’s dig right in…
AON x Gamux DH Prototype belt-drive, gearbox downhill bike
OK, so first off, a micro-refresher on AON Racing.
The team was established just last year by 2020 DH World Champion Reece Wilson to create a “pure prototype downhill race team” free from bike sponsor pressures, allowing them to develop innovative race bikes and components.
Swiss CNC bike maker Gamux was a core partner, enabling the AON team to develop what they thought could be the best DH race rig, without being locked into an existing commercial bike model. Sure, Gamux already had the Sego. But even that bike allowed them to customize the platform tailored to the racer, just like the bike Harnden raced isn’t exactly the same as the one you would buy directly from Gamux.
Now onto the next new bike…
Again, built around a Pinion gearbox to get weight low, protected, and to drop unsprung mass. And again, a high-pivot design, driven by a Gates belt-drive system with an idler pulley and a belt tensioner, which put AON Racing in the running for a shot at the 100,000€ Gates Belted Purse offered to the first Elite man or woman to win a UCI MTB DHI World Cup on a Gates belt-drive bike.
But that’s where the similarities with the previous Sego end. Everything else has changed.
unnamed AON Gamux Prototype DH race bike
Ridden by the 3 guys on the AON Racing team – Reece Wilson, Henry Kerr & Stan Nisbet – the prototype bike doesn’t have a name yet. Actually, a contact inside the team confirms that it does have a name, they just aren’t ready to go public with it yet.
But while the team couldn’t officially share photos of Wilson or Kerr’s bikes because of how many secret unreleased products are on both, they were happy to share still photos of Nisbet’s rig. And don’t worry, it has plenty of tricks up its sleeves, too.
I’s a wild-looking bike, so we have plenty to talk about without a name. First off, it looks more like some kind of off-road cruising moto than a bike, right?
The heart of the AON Gamux Prototype is the completely new, all-aluminum CNC-machined construction, opting for a single monolithic but hollow main frame tube instead of a more conventional front triangle. Then, a seat mast gets bolted on top, the gearbox hung down below, and an all-new high-pivot 4-bar suspension system bolted onto the back.
Pinion gearbox + Gates belt-drive
While the Sego is a high single-pivot with a linkage-driven shock, this new AON Gamux Prototype is a more classic Horst-link, four-bar. It’s still a high-pivot, maybe even a tad higher if my eyes don’t deceive me. And it still has a chainstay-mounted i-track idler pulley, plus a quite complex belt tensioner pulley to keep the Gates connection happy and tight.
No official word on length of rear wheel travel, other than that the team is still tweaking and playing with different figures via various link and shock setups.
It also appears to get a decently low bottom bracket height, and has tons of travel. So North Shore Billet supplies their short and strong Talon cranks to put power into the Pinion gearbox.
Of course, the bike also gets a bashguard / skid plate that wraps around the gearbox for protection, as well.
Intricately CNC-machined U-shaped main frame beam
But much of the beauty of the bike comes from the intricate CNC machining by Gamux. Instead of a simple I-beam structure reinforced with bonded-in carbon, this new AON Gamux Prototype is 100% Swiss CNC’d aluminum.
The main frame is a single massive U-shaped beam.
Completely open on the top, it forms the wide backbone of the downhill bike.
The sides of the mainframe tube are mostly smooth, just with wider reinforcing ribs along the upper edge. But the underside of the downtube(?) features a honeycomb relief machined into the main U-shape, before ribs taper out to form the mounting points for the gearbox and skid plate.
The team explains that this externally relieved design allowed Gamux to significantly increase/control the frame’s torsional & directional stiffness and strength, without adding unnecessary weight. And it also lets them showcase some sweet machining style.
Plus, the external honeycomb machining makes it much easier to manufacture, allowing Gamux to smoothly machine out the inner well of the frame, only keeping a few side-to-side ribs remaining inside for stiffness.
Gamux kept the AON Racing team prototype a bit simpler by designing a modular bolt-on seat mast. That gives them freedom to tweak geometry a bit. But it also simplifies production again – keeping the overall height of the CNC-machined part low, and allowing the frame to remain completely open on top.
Then with a single mainframe member, AON & Gamux are free to tweak the ride and performance of the prototype DH bike by iterating separate suspension parts, like: the rocker link, various length seatstay bridges for different wheel sizes (all mullets so far, but full 29er will be possible, too), or different chainstays and seatstays to fine-tune geometry or rear end stiffness.
Weird and wild cockpit setup
Continuing the wild-looking concept, Nisbet and his teammates were riding various high, set-back cockpit setups.
Prototype negative setback stem?
Here, it looks like Nisbet is riding a ~80mm tall stem with -40mm of offset relative to the steerer tube. That’s also holding a high-rise Ergotec 70mm rise handlebar for a very upright and back position. The unconventional cockpit is uniquely set up to race super steep tracks, on a bike with longer frame Reach designed that way for extra high-speed stability.
We only slightly get a peek at it, but that big silver headset suggests (unsurprisingly) that there’s also plenty of space available for head angle adjustment to further fine-tune geometry to each track.
AON Racing works closely together with the Hayes group – which means Hayes brakes, Manitou suspension & Reynolds wheels. And the team generally has raced on purple Hayes Dominion A4 brakes, plus Sinter brake pads. But those rotors aren’t from the Hayes line-up, though.
They appear to be 2.3mm Hope Fixed Rotors, instead.
Prototype RevGrips with integrated bar ends?
Next to the purple Hayes brake levers, we also spot a curious unreleased product on the AON x Gamux Prototypes.
Medium shock-absorbing RevGrips get fitted with an external bar end flange, designed to let racers push outward on the bars for added control. And they claim to allow a looser grip in the roughest sections of a DH track, without worrying about your hands slipping off the end of the bars. It’s a concept that seemed niche until a few weeks ago, when Joe Breeden and Wolf Tooth made a strikingly similar setup more readily available.
Many more unreleased secrets on Reece Wilson & Henry Kerr’s bikes…
We didn’t get still life bike pics from the other guys, but there’s still plenty of Mona Yongpyong, South Korea World Cup race photos to spot more prototype tech on AON bikes.
Prototype Hayes Dominion brakes?
First, notice that there are no purple Hayes on either of these guys’ bikes.
A closer look reveals the brake lever bodies are, in fact, hidden under what looks like a soft neoprene cover. The silver brake calipers on both racers’ bikes look to have the same layout as the 4-piston Dominion A4s on Nisbet’s bike, but with sharper edges. And the silver levers have a gold piece visible that looks like the end of the tool-free reach adjust on current Dominions.
Perhaps these are the more premium set of Dominion brakes we’ve heard rumored for a while?
Both bikes also appear to have that same mysterious extra wire run along the left/rear brake line like Nisbet’s. We’re guessing it’s just an easy access to charge the Pinion Smart.Shift battery that is tucked inside the frame, right?
Prototype Manitou Dorado fork?
One last key secret we can clearly see is a big piggyback hanging off the damping side of Reece Wilson’s Manitou Dorado fork, with a special blue anodized fork end screaming, “Look at me!”
The standard Dorado puts external TPC+ (Twin Piston Cartridge) high-speed compression damping control at the bottom of the right fork leg. The bottom of Wilson’s fork is clearly missing that adjustment, which likely moved into an extra external piggyback reservoir for more oil volume, adjustability, and control.
What’s also interesting, though, is that Wilson didn’t race exclusively with this fork prototype. So clearly, it isn’t yet the best solution for all DH racing situations, just yet.
Also, all of the team are on Manitou forks labeled as Dorado Pro, which would normally come with carbon upper legs, but they all have alloy upper legs. AON confirms that these are all MRD (Manitou Racing Development) prototype forks using alloy uppers that the team riders are testing for Manitou R&D.
And lastly, what could be hiding under that sock over Wilson’s rear shock, tucked inside the top of the frame? It definitely isn’t the same Mara PB Pro air shock that’s on Nisbet’s & Harnden’s bikes.
Could it finally be a Mara Coil shock from Manitou?
Who knows for sure, but we’re going to keep on the lookout!
