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Bike Check: Mike Huter's Gamux Prototype Downhill Bike

Aug 7, 2023 at 15:17
by Nick Bentley  



The Gamux Factory Racing Team has been testing and riding this custom gearbox downhill bike for a while now, relentlessly seeking out opportunities for improvement, no matter how marginal, in their pursuit of innovation.

Upon closer examination, it's clear why they've taken this approach. The Gamux team seems to seek ways to push the boundaries and elevate their performance. This bike in particular is a significant leap in that direction. Our chance to take a closer look at the latest iteration came during the World Championships in Fort William, where Mike Huter was representing Switzerland.

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Mike Huter // Gamux Factory Racing
Age: 17
Height: 185 cm
Weight: 78 kg
Instagram: @mike.huter

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Gamux Downhill Prototype
Frame: Gamux Downhill Prototype
Shock: Manitou Mara Pro
Fork: Manitou Dorado Pro
Wheels: 29" Reynolds wheels with Ringle Bubba hubs
Tyres: Schwalbe Tacky Chan front and rear
Drivetrain: Pinion 6 speed gearbox with electronic Smart Shift
Brakes: Hayes Dominion A4
Cockpit: Protaper A38 handlebar and direct mount stem
Size: 485mm reach

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The Gamux bike is a bespoke piece of Swiss engineering, with the prototype meticulously machined from aluminum in Switzerland. As of now, the frame is in its finalization stage, and the Gamux team has set their sights on making these frames available for purchase by the end of this year. This endeavour will involve a very limited production run. Prospective buyers can opt for complete bike builds or frame-only kits.

The Gamux frame will be offered in a single size, boasting a reach measurement of 485mm. Additionally, it's designed to accommodate a reach-adjust headset, affording riders the flexibility to extend or reduce the reach by 10mm as desired. Mike is running his Gamux at the standard 485mm reach number.

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The rear swing arm of the Gamux is a stunning bit of machining with weight reduction taken to the max to reduce the amount of unsprung weight.

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The Gamux frame has 198mm of rear travel.

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The most striking feature of the Gamux bike is undoubtedly its Pinion 6-gear gearbox, complemented by an innovative Smart Shift electronic shifter. This unique setup includes a newly designed trigger exclusively tailored for Gamux. The introduction of this trigger and Smart Shift shifting functionality came in during the Gamux factory team's participation in the British Downhill Series at the Fort William round this year. Since then, the system has undergone several improvements and refinements to be what it is now.

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The Smart Shift system has a shifter pod that appears quite conventional, with a paddle to go up and one to go down the gears like any other shifter, but the electronic smart shift facilitates not only conventional shifting but also seamless gear changes under load or while coasting. The gear range, however, remains consistent with that of a standard mechanical 6-speed gearbox that Gamux had been using previously. The shift transitions are practically imperceptible. One of the most striking aspects is the near-absence of noise from the carbon-reinforced Gates belt as it glides through the pulleys.

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When it comes to the fork mounted to the front of Mike's Gamux you find a Manitou Dorado Pro. However, nothing with Gamux remains standard for long. Last year the team switched the crowns on their Dorado Pro forks to the dual pinch bolt versions to enhance stiffness at the front end of the bike. These dual pinch bolt crowns have an offset of 47mm.

The air pressures are set at 175 psi in the IRT chamber. The IRT chamber houses Manitou's Infinite Rate Tune system, enabling advanced spring tuning by independently adjusting air pressures at the start and end of the stroke. IRT technology introduces a secondary positive air spring affecting only the mid-to-end stroke of the fork. This permits the main air spring to be tuned at lower pressures, improving sensitivity to small bumps while sustaining mid-stroke support and controlled end-stroke ramp-up. The primary air chamber is set to 60 psi.

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For rebound, the Manitou Dorado Pro uses the brand's TPC+ Cartridge. This system offers velocity and position-dependent damping, maintaining light damping during small bumps when the fork is highly extended. As the fork compresses further into its travel, the secondary TPC+ circuit engages, increasing damping force for added support and to prevent bottoming out. An independent Hydraulic Bottom-out circuit further enhances damping force in the last 30mm of travel, softening deep travel impacts and preventing harsh bottoming out. The cartridge design includes a spring-backed IFP that fully seals the damper oil, ensuring consistent damping during demanding downhill runs. The cartridge fitted to Mike's Gamux is a standard off-the-shelf unit.

When it comes to settings on Mike's TPC+ damper the high-speed compression setting varies from track to track and usually falls between 4-7 clicks from fully closed. During our bike check, the fork was set at 6 clicks from fully closed. Next, the low-speed compression settings on Mike's Dorado Pro ranged from 3 to 8 clicks from fully closed over the year, with the current setting at 5 clicks from closed. Finally, the rebound is configured to 10 clicks from fully closed.

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The rear shock's air canister has 260 psi inside it. The high-speed compression is dialed in at 3 clicks from fully closed, the low-speed compression is set to 6 clicks from fully closed. Lastly, the rebound has been set to 8 clicks from fully closed.

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The cockpit is a fully Protaper affair it includes a Protaper direct mount DH stem set at 45mm, which is holding a prototype set of Protaper A38 handlebars. The aluminum bars have been cut to a width of 780mm. Additionally, Mike has his bars set with a slight roll towards the rear of the bike, though not to a significant extent.

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Mike's bike features a set of Purple Hayes Dominion A4 brakes, with the levers adjusted to a relatively flat angle. The lever pull is configured to position the bite point 15mm away from the handlebars, this is consistent on both sides.

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The Hayes Dominions work on a set of Hayes 203mm rotors both front and rear. Mike also runs the T106 compound brake pads. These are the brake pads from the T4 light weight version of the Hayes Dominion brake family. This reduces the weight of the pads by half. This, alongside the titanium bolts in the rotors, is all part of Gamux's strive to reduce the mass of the rear of this bike.

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For wheel set up Mike's Gamux has a pair of 29" wheels. The team tested the bike with a mixed wheel set up earlier in the year at a team camp and they chose go with dual 29" wheels this year due to the taller height of their two riders.

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The Schwalbe Tacky Chan tires are set at 27 psi in the front and 33 psi in the rear. Both tires are set up with Pepi's Tire Noodle R-Evolution tire inserts. Along with helping to reduce pinch flats the inserts also reduce noise - the sound of a rim hitting the ground can be an unnerving distraction, which the inserts help prevent.

The wheels are from Reynolds, with a set of SunRingle Bubba hubs. The front wheel uses a Blacklabel 309 DH rim, and a prototype rim that's slightly less compliant is undergoing testing in the rear.

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On a bike as exceptionally quiet as the Gamux, any potential rattling becomes particularly noticeable. To mitigate this issue, a simple yet effective solution is the addition of a small piece of the eye side of some Velcro to the front brake cable. This strategic placement prevents any noise resulting from the cable making contact with the number board.

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Mike's Gamux is finished off with a Protaper seat post and Tag metal saddle.


Author Info:
Mandownmedia avatar

Member since Nov 28, 2019
291 articles

113 Comments
  • 86 1
 DH seems the perfect place for a gearbox , weight where you want it and less unsprung weight for the rear wheel
  • 33 0
 and no more snapping chains mid race run with that belt drive Wink
  • 22 2
 well hopefulyl this will be the beginning of the end of the ancient disposable open chains and cogs
  • 4 0
 I bed every serious top brand must have a hidden gearbox prototype right now to value the pros and cons ..
  • 39 0
 wait is that blue masking tape as the accent on the frame?
  • 16 0
 I'd imagine it's to keep the mud out - there's a lot of pockets for slop to accumulate in.
  • 5 4
 While not really practical at all (painters tape doesn't hold up well, as its intentionally easy to peal off of stuff), it sort of gives it a tron bike look, I like it.

And not just the blue painters tape, I mean the whole thing.
  • 8 1
 Speed tape!
  • 20 0
 It’s Moto Tape. Send me a message — I have a few dozen rolls for sale. $30 USD per roll, but hey, it’s Moto Tape and I have it in stock!
  • 7 1
 Imagine if they'd used tubes, they could do away with the tape (or foam, or whatever it is) altogether!
  • 3 0
 @ocnlogan: that blue tape matches the First Ride logo and the purple Hayes match the Ultra Soft Addix logo. I don't know if it's really made on purpose but I like this sharp kind of details.
  • 1 0
 should have taken the tape off for the pics to really show the beauty of the CNC machined frame
  • 2 1
 @danstonQ: and then the orange grips ruin it
  • 6 2
 I just reached out to the Gamux guys to ask and it’s there to hide some details they’re not quite yet ready to share.
  • 3 0
 internal frame storage
  • 1 0
 @bmxbackground69: completely!!! Pfffff
  • 4 0
 @WRCDH: I have it in green! $35.
  • 1 0
 @bmxbackground69: Mike has been running orange grips to differentiate his bike from the others on the team, not sure if there is more to it or not
  • 1 0
 @znelson: @bicyclepubes could put so many tiny f*cking frame bags in there
  • 2 0
 @boozed: I like to interpret this comment as taking old bicycle tubes and wrapping them around the...beams(?) prior to welding
  • 1 1
 It's not tape. It's foam wedged into the channels formed by the frames I-beam cross section. I had seriously considered buying a Gamux but stopped short after considering just how painful smacking your leg on a round tubed frame can be. The foam might ameliorate some of the negative impact of their frame design in a crash, making the knife edges merely square ones.
  • 2 0
 @gtill9000: took another look. You're right. Tape seems fairly useless to me. I'd hate to take a tumble on this frame. It's tailor made for breaking bones
  • 2 0
 @Euripides-Iripadem: Agree - I don't see what's wrong with a normal tube. Anything else seems unnecessarily heavy and to your point, to many harsh edges.
  • 1 0
 LOL
  • 34 3
 That is hands down, the most beautiful bike l have ever seen. Well done Gamux!!!
  • 2 0
 Although a full profile picture in the article would have been nice.
  • 32 1
 Who turned the 5dev cranks into a chainstay
  • 9 0
 The gnome that hides behind the CNC machine.
  • 6 1
 If they made a frame it would most likely cost over $15K. Doll it up with intend suspension and trickstuff brakes, well over $30K.
  • 9 0
 @brassinne: that’s some hyperbolic math you got there
  • 2 0
 @scary1: That's taking inflation into account.
  • 18 0
 200mm of rear wheel travel is too much and can make the bike feel sluggish and unpredictable in fast sections and berms. With modern geometry, 198mm feels like the right amount of rear wheel travel.
  • 19 1
 The coolest rig in the whole world cup and yes, i've seen Kerr´s Pivot
  • 14 0
 What my DH rig dreams are made of! High pivot gearbox!
  • 12 1
 Love to see a no Big S build. And this bike is just cool in so many ways.if it was available for sale I'd have a hard decision between it and the G3.
  • 12 0
 Favorite looking DH bike of all time now, this kinda innovation > cable tourism
  • 11 1
 Can’t believe no one has said anything about Mike Huter…bet he’s friends with Mike Hunt and Ben Dover. I didn’t even know Mike Huter could ride a bike!
  • 5 0
 He's good friends with my buddy Dixen Ormas
  • 8 0
 It impressed me how this bike visibly tracked better to the ground than any other bike on the worldcup circuit! The new demo comes close and then looong pause. Also the pure silence when the bike floats by. Mesmerizing to say the least.
  • 10 0
 Ok where do I get those dorado decals?
  • 5 0
 2004. I still have some.
  • 3 0
 @Dougal-SC: I think these are updated to fit better?


Also saw a bike on here a few days ago with red ones
  • 1 0
 @boostin: Indeed, I find it funny how just like clothes if you hold onto stuff long enough it's cool again.
  • 4 0
 @Dougal-SC: It never wasn't cool, they just stopped making them like that.
  • 5 0
 You won't BELIEVE what Brooklyn Machine Works looks like in 2023!! Fans are shocked at the transformation. Click here for more!
  • 6 0
 I actually like it… like a lot!! Looks like a fun bike to ride
  • 6 0
 thats a bike. love that swingarm. manitou/hayes ftw
  • 2 0
 Great write up about the bike but damn Gamux Why only one size? I am 8 cm taller then their rider and the ofset headset probably won't be enough for my lanky ass.

Since it will be rather limted it will be hard to try :/ sad!
was or still am seriously considering that one. but now with a big bit of trepidation
  • 1 2
 Meh I don’t think it's a great write-up. Reads like a high school kid's essay where they're trying to impress the teacher. Example: the first two paragraphs. It sounds like they got paid by Gamux for the rave review, and put some of the text through an AI engine to try to make it more impressive.
  • 5 0
 such a detailed review, but no bike weight.
  • 5 0
 I need to invest in some scales to take to world cups with me but I just spoke to Gamux and the say 18.5kg ish depending on the set up of tyres and things like that.
  • 6 2
 The question is when will gamux make a dh bike people can actually buy?
  • 8 0
 Read the article.
  • 4 0
 I HOPE the rear hub is silent af to "hear" the bike itself in movement...
  • 4 1
 I think Sun Ringle's are fairly loud, they should have put an Onyx on the back end.
  • 5 0
 doesn't matter, artificial jangly chain/derailleur sounds will be played over the top of all DH runs, regardless of bike.
  • 3 0
 With the painters tape the front triangle has the vibe of the old Turner DH bikes.
  • 2 0
 Must be hiding some very small tech under those masking tape security screens...
  • 3 0
 This looks absolutely amazing!
  • 2 0
 Zerode G3 or this thing? Both are probably gonna crack 5 digits when they go on sale
  • 2 0
 Bloody hell! That looks mental! Id like to see that in the flesh and having a good to feel how it rides!
  • 2 0
 And still no water bottle holder Razz
  • 2 0
 But if you tear off the blue tape you can store several snacks in the holes. Not too bad!
  • 2 0
 Speaking of weird Euro bikes, what became of Ancillotti?
  • 2 0
 Still going, they make frame on a resquest basis and have long waiting lists. I was considering one but didn't want to wait that long. The guy has you come to his workshop to try the bike and different configurations so you can make your choices and then he will build it.
  • 1 0
 @Balgaroth: That make me happy to know they're still going strong. I would love to see them field a competitive WC DH team once again.
  • 2 0
 By far the most silent bike I've ever seen in my life.
  • 2 0
 Mike Huter. Mi Khuter. My Cooter. Heheh
  • 2 0
 I think this bike is super neat.
  • 1 1
 Spent the season chasing marginal gains - still uses a bolt on is to radial disc brake adapter. That bolts on to the rear of their bike that is held together with bolts.
  • 1 0
 Reynolds hubs are Centerlock and Hayes Brakes are 6B - take it up with the product managers. TBF, the adapters and fasteners are aluminum, not steel, so why not grumble about steel fasteners elsewhere?
  • 1 0
 Am i the only one looking at the shock bolt thinking they forgot to place the nut?
  • 2 0
 This does not look like a Session
  • 1 0
 Anybody actually run that shock?
  • 8 0
 Yes and it's amazing.
  • 2 0
 @Snowrydr01: nice. I love my dorado pro upfront. Might need to try one.
  • 3 0
 I have one on my Capra. Best air shock I’ve ever had.
  • 2 0
 Production Mara Pro has a work-party switch. That's looking like a DH specific one without (full time party mode). I've been on them since about 2018 I think.
  • 4 0
 Yup, that’s my go to shock for five years, best off the shelf shock you can buy!
  • 3 0
 I've had one on two different bikes now, current one is paired with a Mezzer Pro in the front. Hands down my favorite shock if for no other reason than how good it feels with minimal setup time.
  • 2 0
 @skierdud89: yup, my experience is simple and effective set up, easy to tweak for changes in terrain. I think I’ve had four or five Mara Pros with the king can.
  • 1 5
flag zyoungson (Aug 8, 2023 at 14:21) (Below Threshold)
 Most dick looking shock on the market
  • 3 1
 @zyoungson: that’s where your mind went?
  • 1 0
 The crowns have 205mm of travel?
  • 1 0
 I thought this fork maxed out at 203
  • 2 0
 Excellent
  • 1 0
 Live Unchained,,,,oh wait. Bike looks the business though.
  • 2 0
 Privateers Dream. Sold
  • 1 0
 Kalo di gua Ngamuk namenye bor.
  • 3 3
 Someone go and test it in a British winter. They'll soon find out why a belt drive is a terrible idea for a drivetrain.
  • 2 0
 Why so? Genuinely interested.
  • 2 0
 @Woody25: it's no worse than a chain, these guys have certainly tested this bike in muddy WC conditions - dunno if this KrisLord character has ever ridden a WC DH track so...
  • 3 0
 @therealmancub: To be fair to Kris, he's done his time racing in the British winter www.rootsandrain.com/rider206/kris-lord/results/filters/page1
  • 2 0
 @Woody25: And some respectable results in there too.
  • 3 0
 I ride all winter in north shore mud with a belt and zero problems.
  • 2 2
 @Woody25: For the same reason that they don't appear on Motocross bikes, despite the tech being around for decades. As soon as you put the power down all the schmoo, stones and peanut butter just get squished into the belt. A chain naturally clears all of that.
Belt drives sound brilliant for long distance trundling and commuting, but for a DH race bike, not so much.
  • 2 0
 @KrisLord: I can't speak to running a belt in moto, but on a MTB they clear mud as well as a chain. Not better or worse, about the same. Conditions that will plug up a belt will also plug up a chain and cassette.
  • 1 0
 Looks nothing like a Trek! Ha ha
  • 1 0
 Looks like a Sess... erm... a set of Meccano.
  • 1 2
 Dear Hayes, when can we expect a Mara Coil? Also, how about nixing 203 rotors and go 200mm for ease in compatibility and reduced SKUs?
  • 2 0
 220 are already available - end of story!
  • 2 0
 Gearbox all the things!!
  • 1 0
 Wait what is the guy's name?
  • 1 0
 Reminds me of Brooklyn Machine
  • 1 0
 take my money for the trigger shifter !
  • 1 0
 take my money for the trigger shifter !
  • 2 3
 Where’s my e-bike with gearbox? Slightly heavier? Little drag? Who cares.
  • 1 2
 With that Dorado mounted they should call it the "Compliance king" or "The wet noodle"
  • 1 3
 Now where have I seen this before.... Zerode G3
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