Gamux Reveal Updated Prototype Machined Gearbox DH Bike
You may have seen our earlier article detailing Gamux's efforts as they test and refine their prototype CNC machined gearbox downhill bike over the course of the season.
Since the Les Gets World Cup at the start of July, the team has been very busy. They set to work to make the most of an extensive testing period that concluded at the french round to fine-tune their prototype downhill bike. The outcome of this period was a desire to change the rear end of the bike and try and refine the kinematics to achieve the stiffness and ride feel they wanted.
The result is the new prototype. This bike, they say, manages to realise a lot of the changes they established needed to be made during testing. Once built up, they received this model two weeks prior to the Lenzerheide World Cup. This is the last prototype. The prototype is "98%" of what the production bike will be. The pre-order slots are open via their website and available for a small deposit.
There will be some minor alterations in terms of fine-tuning aesthetic changes for the production run. The final bike will be slightly less angular and will feature a new symmetrical rear end.
The new single-pivot setup.
The frame kinematics and frame stiffness will largely be the same, and the production bike will feature changeable dropouts so the rider can choose between three different chainstay lengths. The production bike will also feature flip-chips to change the leverage curve to optimize it for air or coil suspension. The frames will also come with headset adjustment cups to give the rider options of plus or minus 5 or 10mm and a zero offset option.
A large difference since the model in Les Gets is the change from a four-bar to a linkage-driven single pivot. This was mainly done to achieve better stiffness in the front triangle while also saving nearly a kilo in weight. They also hope to remove another 600-800 grams with the production model.
The Gamux is nothing if not slightly unconventional, even if it does come in a sleek alloy package.
Down and up, or up and down. Either way, this is a great solution to the sometimes unfavoured grip shift on other Pinion-equipped bikes.
The bike uses a Pinion gearbox to keep the weight low and remove any vulnerable componentry such as rear derailleurs. It features an interesting two-paddle system for gear changes, which is one of the neater gearbox shifting solutions to date and, in my opinion, far outdoes the grip shift you may well associate with Pinion. Gamux also feels that the Pinion gearbox offers lots of reliability that couldn't be achieved with standard gearing.
In terms of production, the bike is available for pre-order which will conclude in October. They are aiming for delivery in February. In terms of build kits, there is the option of frame only, as well potentially both Manitou and Ohlins setups.
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dirtmountainbike.com/dirt-100-2015/empire.html
Edit: not sure how I feel about this outside plus thing. It used to just be PB plus, back when I was supporting an independent website that I loved, that I had, but I'm not really sure I want to be associated with outside. Has a different feel and different standards.
I thought of the same bike the moment I saw this. I'm guessing the downvotes are because people are picky over the empire being cast with some finishing machining which is quite different from this.
www.pinkbike.com/photo/12167463
I'd just buy some nu'uns!!
Sand is cheaper as we make a wooden pattern to make the sand moulds, probably better for your needs as they're not under pressure or much tensile strength like motor or hydraulic parts. Sand casting is more prone to the inherrent flaws of casting and better for lower production rates.Then they're still gonna need some last CNC work for precision
But still, if your'e only wanting a few parts a year, then CNC from billet would be more cost effective
I’m more concerned here as to why is a very inefficient manufacturing method being used to make a bicycle.
-Black Elk
Cool concept, anyway.
This is an attempt to reduce cycle time, tooling, and will come at a significant weight penalty. Theoretically the above design could be done with two sides facing the machine. If they were to make it feature more hollow areas it would take minimum twice the handling into and out of the tooling/machine. It also would require bonding of frame halves together. Which in theory compromises the performance of hollow shapes, but IMO not to the same extent as the I beam shape does.
I would be interested in one (in theory) if it didn’t go down the I beam path. Still, I think this is a very cool achievement.
They said they want to create a customer only frame. Meaning you choose the model and with in the limits of its design you choose the geo. That is a pretty easy way to make custom frames. Do that with regular tubing and I doubt you are faster because of all the other things you need to do first.
I also dont think you are faster if you are a real small company if you do the traditional way. Frame Welders are way more rare in the EU then just a machine engineering contractor. I have 30 companies around me, 50km max. Guess how much frame welder ? Zero...
I saw how much training Nicolai put into their welding guys. You need a already trained person who took 3,5years to get that degree and then train it inhouse for another year. Before he ever can touch a real frame.
CNC tooling on the other hand is way more easy.
A friend of mine works at a company that makes cars with 3D printed chassis and is saying that their cost is pretty much on par with the forgings done in high end car chassis, like an Aston Martin.
If they are trying to be a small boutique, 100% custom geometry bike company, why not go all the way?
I never looked to deep into the process so I cant say shit about it otherwise then there are not that many that do this and have a capacity.
The only other thing I know is that the printing is just not as fast as Milling that thing.
Also you need to engineer it different then a milled frame and it could be that they don't have that kind of knowledge right now.
Would be cool to se a bionic printed FS frame though.
But, the opportunities available with 3D printed frames could be really amazing. Suddenly internal routed housing is structural, and why can't you just thread your rear brake housing into the frame at the head tube using the internal routing as your brake line. Funny shaped frames are just the bonus.
A CNC machinist is about 4-5 years of training, it’s no less of a trade than a fabricator. Plus you need to couple that machinist with a machine worth hundreds of thousands of dollars (50,000 will get you an entry level 3 axis with a small work envolope, a 5 axis machine with a good size envelope will be above 200k and you haven’t bought any tooling for it yet).
Those 30 machine companies near you are going to laugh a CNC bike frame idea out there door. There is far more profitable jobs they can and will do with their machines.
I don't talk about a regular fabricator, I don't know if your actually involved in development and the stuff we deal in QC for just get one contractor that's good enough.
Not to mention that its so easy nowadays to get the CNC ready. Most of them can and will chug the CAD. Do you need a machinist still for that ? Yes but he doesn't do that much then correct it a bit and over watch the machine for a bit. Did you wrote your programs on the oldest type of machines? I did and it was so freaking slow. I also laugh about the new machines because they are so f*cking fragile and under engineered.
Yeah they will laugh and will make Trickstuff brakes instead
There is a reason why, beyond a few overpriced frames no one is CNCing entire frames.
I haven't welded a bike frame, but am planning on doing it here shortly, but I have welded up several small race car frames. Getting everything to hold tolerance is so much harder when dealing with a welded piece than a machined piece.
I do agree though that a wholly CNC'd bike is quite wastefull, and that is why I was wondering why they didn't go for a fully 3D printed frame for this type of application, of super low volume, and customizable bike, that seems like the right method to me.
The best part about this is that you get a better riding frame too.
Post weld machining can be done with simple and basic hand tools available to even a hobby builder.
As for 3D printing, same machine cost time is the same and still requires post machining, add to that an inconsistent dendritic structure of the material and you discover why not much of anything that is load bearing is 3D printed.
I use 3D prints for very small items for investment casting. (Smaller than your fist) Some of these prints take up to 7 hours if they are complex. Expand that up to the size of a frame. Factor in the cost of running a laser for that long and the cost of the printer medium and you can understand why 3D printing anything large is inefficient. 3D printing on that sort of scale really only has its advantages in providing internal component details that would be impossible with more conventional methods. It does have its place.
Making bicycle frames? If you want to spend 20k then I guess.
Printer media price is coming down dramatically all the time. The speed is pretty quick since newer machines have as many as 13 heads.
They can control the grain structure of the material by what angles that the lasers are at. People are printing hypercar chassis out of aluminum, so I think that it could be figured out how to make a bike frame that is strong enough.
I haven't done a cost analysis on what it may cost to print a frame but maybe I'll ask my friend that is quite familiar with the newest printers. I'm not guessing that they would be super cheap, but I kind of bet it would be under 20k.
I have billed out v12 block's out of Al. The so called waste would be the same for this frame. You don't need a thick slab.
They are print parts of chassis’s, and well it’s a hyper car, there not exactly high production or cost effective vehicles.
And for that added cost, even if I’m being hyperbolic, what are you getting for your extra cash apart from “I have a 3D printed bike”?
That’s funny
Besides that you are still comparing big apples to little apples. Ally frames are still stiffer than comparable steel or crfp
Would you rate aluminium ove Cfrp for a flexors joint?
It might be you who is lacking understanding if that’s what you’ve reduced the conversation too and perhaps cannodale is better off without you.
I'm not saying that making a 3D printed bike is the most economical, but the economics are changing constantly in this area. The reason you would want to 3D print a bike is pretty obvious. If you wanted to try a new design you could do the computer work and then just print it and have that new front triangle or whatever part, the next day, no real fabrication needed. There is very little wasted material, no machining tool wear. If the economics work, a company like the one in this article could 3D print their custom one off designs for customers instead of CNCing the frames. You are able to totally optimize the structure, without needing to compromise or work inside the confines of traditional manufacturing methods, like low manufacturing ops or needing to use common tooling.
Since this tech is changing so fast we will probably know where it will be heading in a few years, likely right as all the manufacturers switch over from carbon frames to all printed frames.
For me, I'm not a fan of the grip shift, nor the two-cables from one shifter look. I have had a play on one and the odd ride but I've never owned a bike with one so who am I to say really? I do I think though that it's seen as one of the barriers for a wider uptake of the Pinion system. Horses for courses though. Cheers
It's the shifting mechanism as a whole system that needs to be considered instead of individual components.
It typically happens when you don't know something real well and you find yourself coming in hot, into a corner that is going to pop you up a bit of a hill or rough, flatter section. Big advantage to be able to hit the brakes, then get one full pedal stroke in, while ratcheting up 3 or 5 gears real quick. When I used grip shift I would have to move my hand over to get to the shifter then twist. Definitely couldn't do that while on the brakes.
I wish pinion really paid attention to our cries for a trigger shifting mechanism. It is a significant obstacle for me to buying a gearbox bike. The cinq shifters are a step in the right direction but not nearly enough to get me on a pinion equipped bike, which I would happily pay a premium for over other boutique frame/bikes
@chopper-uk cinq.de/en/shifting-technology/428/shift-r-tour-for-pinion These are the ones you want for an MTB. Still not anywhere near as good as the big Ess’s triggers and bloody expensive but a massive upgrade for me.
Why did I mention effigear at all? Because they use the Pinion mounting now.
www.effigear.com/en/86-The-Mimic.html
Cheers for that. Makes sense
I find I'm often shifting coming into sections where I know I will exit with more speed, or I need to gear down for something more technical. If you make a mistake, and need to pedal to make up time, it's probably a good idea you in the correct gear. Sometimes throwing in a couple pedal strokes from time to time to gain some momentum may be required as well. Adding into the fact, that being in too high of a gear in the wrong sections can inhibit suspension performance (sustention layout dependant).
The amount of gearing on the other hand is less important, as I would typically shift across maybe 4-5 gears during a run.
Either way dammit we need to see more raw aluminum bikes. I love a good carbon bike but I’d get an industrial shiny metal bike over a plastic one any day.
Also, say what you like about the performance, but an inverted dual crown fork will always look so much more badass than a conventional fork! *
* Except the Monster T - that was in a class of its own, haha!
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