Bike Check: Andi Kolb's Gamux DH Prototype

Jul 4, 2020
by Ralf Hauser  


Andi Kolb showed up to the iXS NotARace Test Session with a prototype DH bike from Gamux, a Swiss company that's focused on creating customized products via 3D printing that are tailored to the end customer or, in terms of their Factory Team, their riders.

At this point, Kolb's workhorse doesn't even have an official model name. Two options have made it into the final selection process, which one it is will be revealed at the official presentation in September, originally planned for the Lenzerheide World Cup. Since that has just been cancelled, we’ll get updated on the new plans.

Trying to keep production as local as possible, the frames are welded in Europe. All frames feature custom built geometries within a range of parameters that Gamux feels are representative of their brand.

Andi reduced his reach compared to his last year’s Commencal Supreme down to 470 or 475mm, depending on the offset he’s using. He felt that he was a bit too stretched on his old bike in tighter corners, and with longer chainstays on the Gamux they kept the wheelbase the same length. Kolb was also asking for a low bottom bracket height, which now sits at 347mm.
Andreas Kolb // Gamux Factory Racing
Age: 24
Hometown: Moosheim (close to Schladming), Austria
Height: 184 cm / 6'0"
Weight: 75kg / 165lbs.
Instagram: @andreas_kolb66

Head angle is sitting at 63 to 63.5 degrees, depending on setup and adjusted ride height of the fork. They ran prototypes as slack as 62 degrees, but didn’t get along with that feel.

When the bike is launched riders will be able to choose their preferred wheel size. Usually, Andi rides 29” wheels front and rear. At the NotARace test session, he was trying out a smaller 27.5” rear wheel for the first time to see if he could add to the bike’s agility while still remaining stable due to the long chainstays.


Photo Leopold Hermann

Photo Leopold Hermann
Gamux DH Prototype Details
Frame: Gamux DH Prototype
Shock: Öhlins DH38, 200mm travel, 120psi main chamber/ramp up chamber 245psi, 1 spacer negative chamber, 1 spacer ramp up chamber, custom tuning
Fork: Öhlins TTX22M, 200mm travel, 480 lb/in spring, custom tuning
Wheels: Pancho aluminum 29” front, 29” or 27,5” rear (testing at the moment)
Tires: Maxxis Minion DHR II, Prototype
Drivetrain: Shimano Saint 9 Speed, 36t chainring
Brakes: Shimano XTR, 200 mm discs
Handlebar: TAG T1 Aluminum 780mm
Stem: PRO Tharsis 9.8, 50mm
Weight: About 17kg/37.4lbs.
More info: www.gamuxbikes.com

bigquotesI thought that I would run into trouble on the straights coming from a super stable Commencal Supreme, but with our suspension and geometry setup on the Gamux there are zero problems.Andi Kolb

Photo Leopold Hermann
Andi is running a chainstay length of slightly more than 460mm.

Photo Leopold Hermann
The dropouts are 3D-printed, to easily make adaptations to wheel sizes and chainstay length.

Photo Leopold Hermann
The links are also 3D-printed, allowing Gamux to quickly adjust or individualize kinematics.

Photo Leopold Hermann
Shimano Saint drivetrain with XTR brakes and 200mm rotors front and rear.
Photo Leopold Hermann
Kolb is picky about his tires, almost exclusively riding Maxxis DHR II on the front and rear and only switching to Shortys in extremely muddy conditions. In this case, he's testing some Maxxis prototypes.

Photo Leopold Hermann
Andi likes to run his bar with a lot of back sweep, but is currently trying to rotate it forward again to avoid dropping his elbows.
Photo Leopold Hermann
Kolb is very picky about his grips. TAG T1 Braap models suit him fine.

Photo Leopold Hermann
Andi prefers his setup on the stiffer side, running the rear end with 22 to 23% sag.
Photo Leopold Hermann
Welded in Europe, massive gusset on the top tube included.







81 Comments

  • 47 1
 That KHS top tube mold just refuses to die
  • 3 0
 Standover anyone?
  • 6 6
 That khs bike is sooooo ugly
  • 3 5
 Strong or pretty, pick one.
  • 7 15
flag freeridejerk888 (Jul 3, 2020 at 17:42) (Below Threshold)
 I choose both and got a Santa Cruz....@blackthorne:
  • 2 5
 @freeridejerk888: amen brother!!!
  • 3 0
 Liking that low set dual link, more please.
  • 23 1
 Looks like the old GT Fury
  • 16 2
 Ooh, in the first picture the Presta valves aren't perfectly centered with the word "Maxxis"
  • 13 29
flag fartymarty (Jul 3, 2020 at 12:25) (Below Threshold)
 Presta, yuck give me Schrader any day.
  • 3 14
flag vinay (Jul 3, 2020 at 14:01) (Below Threshold)
 @fartymarty: Yeah, I hate presta too. Is there a Schrader valve with the holes at the side of the stem (like Pepi or Cush Core) instead of at the end? I use a tube (ProCore) that would otherwise block the valve so that forces me to use Presta. If there is a Schrader alternative I'd get that in a heartbeat.
  • 3 3
 Cuntyy
  • 2 0
 Oh! good catch,
  • 3 5
 Presta is for weight weenies and roadies with super skinny rims. Be brave people get the drill out and give Schrader tubeless a go, you won't look back.
  • 2 0
 @vinay: I use either Stans or Joe's schrader tubeless valves. I've drilled all my rims out for as long as I can remember (since every rim manufacturer went to presta).

Can't you just drill 2 holes?
  • 2 1
 @fartymarty: I once tried to drill two holes in the sides of the rubber bottom part of a valve, but it was hard to keep these open. They'd constantly clog up because it is still a hole in a piece of rubber. Next attempt would indeed be to go all ghetto and use a long schrader valve from a tube, use the metal nut on both the inside as well as the outside and seal it with a perforated piece of tube. I'd only need something to seal and protect the bottom end because a valve from a tube obviously doesn't have that. But as it touches the tube (that does the ProCore duties), it shouldn't be sharp. Alternatively, I could close the inside of the ProCore airguide. Just thought that up, should probably work so I'll try that.

Indeed until I started with ProCore, I only used tubes (no tubeless) with Schrader and always drilled out my rims. ProCore is nice but their own tubes are absolute horror with the two way Presta valve. So soon enough I drilled a second hole for the tube and the original hole got a Pepi valve. Still stupid though. I switched from Presta to Schrader well over fifteen years ago, as occasionally the valve core would come out along with the valve cap. Now I occasionally still have that when I unscrew my (Leyzine) mini pump. I just don't get what people like about Presta. Even more odd, I don't get how we're being downvoted by simply stating we prefer Schrader over Presta. Would love to see one of those downvoters collect the courage, step up and explain how they were offended and what's superior about Presta.
  • 1 7
flag ricochetrabbit (Jul 4, 2020 at 5:36) (Below Threshold)
 Why not just use a schrader tube and call it a day? Tubeless is a pain in the ass for no added benefit in my opinion @vinay:
  • 3 0
 @ricochetrabbit: I haven't had a pinch flat in years. Last ride I had with tubes, 3 pinch flats in ~4 hours.
  • 1 0
 I have only got a flat on my bmx bike. Never the mountain bike. Maybe I have been lucky idk @fruitsd79:
  • 1 1
 @ricochetrabbit: have you ever heard about the tubeless benefits? Clearly not
  • 2 0
 Sure I have. I just don’t think the hassle of tubeless outweighs some of the benefits. Tube takes minutes. Don’t have to worry about seating, sealant, etc. I run tubeless in the rear..tube up front. @Bikerdude137:
  • 2 0
 @ricochetrabbit: if you have the right rim / tyre combo tubeless is nearly as fast to set up as tubes. You can pump them up with a track pump and don't need an inflator. I did 2 tyres yesterday (albeit without sealant) and it was done in under 10 minutes. The secret is having a good deal between tyre and rim - 1" wide Gorilla tape is your friend on this.

Adding sealant is easy using schrader and a Stans injector - you just inject once the tyre is seated.

I wouldn't go back to tubes, I would be fixing pinch flats and thorn holes constantly.
  • 1 0
 @vinay: I'll PM you, sounds interesting
  • 1 0
 @ricochetrabbit: it takes an extra minute for me, a 13 year old to do tubeless tires without even using tire levers, i don't seem to find any hassle, although there are some rims don't know any names) that make it insanely difficult to put tubeless tires on, i would highly recommend trying it on any new bikes that you get in the future because it might change your mind
  • 1 0
 Funny you mention that..yesterday I put on a new der baron, and it was th easiest tubeless setup I have ever had. Took 5 minutes. Tire went on the rim no problem..seated no problem with a floor pump. Didn’t even put sealant in yet. Hasn’t lost a single psi @fartymarty:
  • 1 0
 @ricochetrabbit: Actually I only started running ProCore two years ago (May 201Cool . Until then I've been running latex tubes with Schrader valve (so the green ones from Michelin) for probably a decade or so. I was quite happy with them. I ran them at about 1.5bar, I could swap them in minutes on a ride and patch them at home. It was pretty easy and good. For my current bike I was willing to give tubeless a shot, but I had a requirement that I would be able to do it with a mini pump. For just in case. That's why I went with ProCore (which technically isn't tubeless, obviously. But you are working with a tire that holds pressure so you're getting the same advantages). In the instruction videos, Steffi Marth installs them with a mini pump so that did it for me. I eventually always used the track pump at home but it is nice that it just seals instantly. You don't need to continue pumping a high flow rate to force the bead to seal as the tube already pushes it tight. Only downside with the complete system is their complex Presta valve. It clogs up and you can't clean it out. So I just drill a second hole (or actually, my rims are from Syntace so they already have the second valve hole, just had to drill it up to Schrader size) and I use a thin regular tube and a Pepi valve (others like Cush Core etc should work too). So I slide the airguide over the Pepi valve. When installing, I inflate the tube up to 3bar before I inflate the tire to 2bar (and unless it is punctured from the start, it doesn't lose any air at all in the process). I then continue to inflate the tube up to about 5 bar (should be between 4 and 6 bar) and shake it a little. The drop the pressure in the tire to what I want it to be and I'm good. Pretty quick process too. I like that I can ride low pressures without worrying about the beads burping. If I'm going tubeless(ish), I want to have my cake and eat it too!

I agree just tubes will always be quicker to install and if you're happy with what you have then don't feel forced to convert. Back in November I ordered the Tannus Armour system. It is a foam that goes between the tube and the tire, so the actual tire doesn't need air. I was willing to give that a shot and try it in a spare wheel. After I ordered it, they told me it would take another three weeks as it was quite busy. Ever since I've tried to contact them a good couple of times, no response yet. Seems like a nice middle ground between just tubes convenience and something that goes towards tubeless performance. Still seems like an interesting concept and once it drops I'm definitely going to try it. You'd just need patience. Like, a lot of patience. Eight months of patience and counting...
  • 1 0
 @ricochetrabbit: I ran mine today without sealant and it was all good.
  • 13 1
 2012 norco aline
  • 3 1
 Please
  • 1 1
 2020 Pivot Phoenix 29
  • 12 1
 Raw metal always gets my attention.
  • 10 0
 nice MDE Lumberjack Smile
  • 3 0
 I thought exactly the same!
  • 1 0
 Exactly the same links used by the look of it.
  • 2 0
 Hey @Stokedonthis Smile

Your eyes for sure are up to something here.
GAMUX uses the DH-Link system, developed by Federico Biora from MDE, but the Bikes are not produced by MDE and the manufacturing is completley independent from MDE.
So let's say GAMUX has taken the excellent kinematics from MDE and modified the frame to suit our riders needs.

Cheers
  • 6 1
 Finally a reasonably talk guy who is not preaching the idiotic reach mindset. Love the bike
  • 1 0
 Strang that the front triangle looks completely different from the one in their YouTube video. youtu.be/zNDG1UH9Jhg
Seems to be the second option that is mentioned in the second paragraph here. The front triangle from the video looks way more refined and seems to lend at least the top tube from the MDE Damper. Looking forward to see how this develops.
  • 2 0
 Hey @Inigo-Montoya Smile

You sure have deep MTB-knowledge Smile
You are right, we are trying some different tubings right now to modify stifness and durability of the frames.
GAMUX uses the DH-Link system, developed by Federico Biora from MDE, but the Bikes are not produced by MDE and the manufacturing is completley independent from MDE.

So let's say GAMUX has taken the excellent kinematics from MDE and is now searching for the ideal frame and tubing style, modifing the frame to suit our riders needs.

Cheers
  • 1 0
 Are you sure the links and dropouts are 3D printed? I don't know of a printing process that produces such a smooth surface finish.

*EDIT* OK, I can see the lines on the brake mount.
  • 3 0
 Indeed, or they've been smoothed out in a micro ball thing, but I don't really see the point of reproducing CNC shapes if it's 3D printed. These "chisel" shapes in the dropout are typical CNC shapes where your dependant of the drilling tools dimensions, if it's 3D printed you're supposedly able do model transitions as smooth as possible.
And all in all in that case I don't see what advantage 3D printing would bring over CNC, though I don't know the cost of each.
  • 3 0
 @Will-narayan: I'd have to assume that CNC is going to be cheaper than 3D printing for some time to come. At the very least less time consuming since the 3D printed part probably has to go into a minimum three-axis at the end to finish the bearing bores. There's probably going to be less waste, since you're not removing all the negative material, but the amount of energy consumed by the sintering laser has to be significant. Probably the least expensive way would be a forged part with minimal CNC finishing.
  • 1 0
 @BikesBoatsNJeeps: Yep. Also now that I think of it, you have to program the CNC routing, and this may take time or may not be tweakable even for small modifications, in that case I see the advantage of 3D printing.
  • 4 0
 Pretty sure there's nothing 3D printed on this frame, at least bit the parts mentioned. These are just normal milled parts.
(Which is totally fine and MDE makes some pretty milling)
IF for example the links were printed I would at least expect them to eliminate the pockets so they don't collect dirt...
  • 2 0
 I would call that statement "3D printed links and dropout" - a bullshit. And printed from what - ABS?
  • 2 0
 @Rainallday: at least their parts on the homepage all look suspiciously plastic-y...

Their statement is definitely not adding to the credibility

As opposed to atherton's lugs I also don't see the benefit of 3D printing those links
  • 1 0
 @nsp234: oh yes, those caps, spacers etc. But not high load parts like links and brake mount.
@Pedro404: looks like they just brushed the surface with sand paper a bit to make these lines Smile
Why make all these falls statements while just straight up using MDE frame?

By the way, why shifting cable not attached to derailleur on this bike (photo about rotor size) ?
  • 1 0
 Hey @Pedro404 , @nsp234 , @Rainallday , @Will-narayan , @BikesBoatsNJeeps

Your eyes did not fool you, the linkages on the bike are not printed (Editorial mishap by the writer i ques). But you can find picuters of the printed parts here:

www.pinkbike.com/news/tech-randoms-notarace-ixs-cup-test-session.html

We are currently testing different suspension layouts with different linkage configurations. 3D printing is helping us to acheieve this in a very short time without having to re-calibrate a CNC machiene for a single link. Also it allowes us to fully use AI-based generative design to develop stronger but lighter parts. This would not have been possible with CNC due to it's manufacturing limitations.

Cheers
  • 3 0
 A customized Canfield ONE. Nice to see custom geometry and kinematics. Customization must be the future.
  • 1 0
 similar but no. Regular MDE bikes . model 69
  • 1 0
 @jergus: Hey @Inigo-Montoya Smile


You are right, GAMUX uses the DH-Link system, developed by Federico Biora from MDE, but the Bikes are not produced by MDE and the manufacturing is completley independent from MDE.

So let's say GAMUX has taken the excellent kinematics from MDE and is now searching for the ideal frame and tubing style, modifing the frame to suit our riders needs.

Cheers
  • 2 0
 MDE bikes. Suspension is designed by owner Federico Biora and called I-link. Model of this bike called 69 and it was in MDE offer couple years ago.
  • 1 0
 So it is an I69?
  • 3 0
 That's almost identical to a Turner DHR.
  • 3 0
 For me it looks like a Turner DHR 2013
  • 3 0
 That looks an awful lot like the canfield linkage layout
  • 1 0
 What a nice 780mm stem, oh yeah what size bike is that, it's just a pro tharsis 50mm
  • 1 0
 So these Proto DHR II’s. Is it casing or are those knobs a little more spaced out?
  • 2 0
 "Welded in Europe" sure no sign of hi-qual anymore.....
  • 1 0
 Someone is demasiado picky picky picky picky picky....
  • 1 0
 so what is the chain stay length?
  • 1 0
 Slightly more than 460mm.
  • 1 0
 @DH1977: proper.
  • 1 0
 a modified/new version of the mde lumberjack
  • 1 1
 why are seattubes going around on both sides of the shock all of a sudden??
  • 1 0
 Cuz' it wouldn't work well if it intersected with Wink

More seriously, if by "all of a sudden" you mean as on every recent Santa Cruz and some other bikes, probably because it's a good place for the shock (low CoG) and also for kinematic (to have a good antisquat/IC with a VPP the links have to point in that area, therefore the shock can't be much further in the frame, or you'll add weight/links, etc) and technology may be better now to do it. I'm not sure Santa Crue could have done their current frames 8 years ago.
  • 2 0
 Flip flops.... seriously
  • 1 0
 i like the way linkage is laid out
  • 2 0
 2015 Daimondback DB8
  • 1 0
 Other then the top tube its a mighty fine looking rig.
  • 1 0
 Yes, awesome. I loved not paint alloy frame)))
  • 1 0
 It's like a norco shore made a baby with an old Giant faith.
  • 1 0
 Looks like a mountain bike with shockz
  • 2 1
 Nice Diamondback DB8!
  • 3 2
 Oh it's BEAUTIFUL.
  • 2 2
 Common, 184cm is a touch more than 6', give the guy a break
  • 17 3
 You're right, he's actually 6.0367 feet tall. Is that better?
  • 5 0
 @mikekazimer: don't listen to them, if you can round down 1cm to 6 foot I can round up 1cm to 6 foot.
  • 1 0
 Looks pretty damn sick!
  • 2 1
 Looks like a session
  • 1 0
 Looks like a TR500
  • 1 0
 Nice Lapierre

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