A Closer Look at the Production Privee CNC'd Downhill Bike

Feb 8, 2021
by James Smurthwaite  

In January, Production Privee broke the news on the team change that nobody saw coming. As a company that primarily specialized in steel hardtails, it came as a great surprise to see them unveil a CNC'd aluminum downhill bike for Alex Marin and the Brigade downhill team.

Although Production Privee's name is the one primarily attached to the bike, it was actually created in partnership with Forestal Bikes. Forestal is another Andorran brand and they own a production facility in the small principality. The two brands announced they would be working closely together in March 2020 with the aim of creating "bikes that break the mold". We saw the first fruits of their endeavours with Pavel Alekhin's custom titanium dirt jump bike unveiled in December last year.

Production Privee titanium dirt jumper

From what we can tell, Forestal will continue working on its upcoming eMTB, while Production Privee will make handmade and unique frames from the same factory. This downhill bike is primarily an R&D exercise for the brand and the first step on a path that should eventually allow them to, "design, engineer and manufacture [a bike] in quite short notice". Although Cedric Gracia is involved with the Forestal Group for testing purposes, it's the Brigade Team that will be taking the lead on this project.

The Construction


This downhill bike has been a surprisingly quick project to pull together for Production Privee. In-house manufacturing apparently meant that after the design team scribbled for a month, the engineering and machining stage of the project took just three months and then the bike was ready. Production Privee admit that a large part of this project is R&D for future projects and say that the advantages of using CNC production are " the freedom of shaping, thickness management... the ability to modify design, geometry, structural, kinematics parameters quiet fast."


This isn't the first time we've seen a CNC'd downhill bike. Most recently, Isak Leivsson was testing a 200mm version of Pole's Machine that could well have been the longest World Cup downhill bike ever. There is a key difference between Isak's Pole and the Production Privee's bike though. While both bikes are milled from aluminium in 2 separate sections, the Pole bike is glued whereas the Production Privee is welded.

There are quite a few machined-in flourishes, including these swirls on the downtube. and an integrated seat clamp

At the moment, Production Privee is keeping any geometry or other numbers close to its chest although they will tell us that each bike will be tailored to the needs of its rider.

Suspension


The suspension system is based on Forestal's Twin Levity system. This is a linkage driven single pivot that has been adapted from the Forestal Syrion eMTB, although Production Privee have played around with the leverage ratios and travel to suit it to downhill. Apparently the brand would have been willing to go back to the drawing board if the Brigade riders weren't happy about the performance, but the first reviews from Alex and the rest of the team have been enthusiastic, so it's the system the team will be sticking with.


What's next for Production Privee & Forestal?

From what Damien Nosella, founder of Production Privee, will tell us, this bike is more of an R&D project than a serious commercial proposal, although the brand has said a production version could be available by 2022.. He said, "using alloy is part of deeper R&D program we’re carrying. As we are starting our production facility with the targets of setting up new manufacturing processes, being able to CNC and weld alloy are a small part of what we need to achieve... It’s more a milestone needed to be achieved leading to new stuff that we will implement during the year." Damien has also told us that he hasn't yet fully turned his back on steel and that only parts of any future chassis will use CNC'd aluminium.

Reading between the lines, we're expecting Production Privee to combine new school and old school production techniques in a similar fashion to Actofive's very impressive P-Train that was released in May last year. There's no timeline on any future projects yet but what better place to test a new direction than in the furnace of World Cup downhill? We'll be watching the Brigade team very closely to see how their new frame gets on.


116 Comments

  • 68 8
 I don't see the advantage over a carbon frame, a great project for tweaking your CNC skills, but isn't this just a more expensive way of making an aluminum bike? It's like the ancient Sumerian saying, "If it ain't broke don't weld it"!
  • 79 4
 I'd imagine that the advantage over a carbon frame is not having to spend $100k on a mold that may or may not have ideal geometry.

Less clear on the advantages over just welding some aluminum tubes together though.
  • 36 4
 You must appreciate the art behind it to find it valuable.
  • 33 2
 @toast2266: but if you can cnc a bike couldn't you cnc a mold? Isn't that what hope does?
  • 12 0
 genuine question

why carbon fiber molds are too expensive?
  • 6 0
 @toast2266: I guess you can vary the thickness of the metal at lots of points to save weight? Only a guess but maybe you can make the equivalent of some super complex butted tubes?
  • 15 0
 @Noeserd: Realistically one mold is a lot less than $100k. A size run of frames might cost $100-150k total. But the molds are expensive because, among other reasons, they're machined to much tighter tolerances than that frame. You can still see the tooling marks on that frame, but those would be polished down in a mold. The molds are also just bigger pieces of metal that are designed to be used over and over.
  • 69 2
 Making molds for carbon fiber bikes isn't as simple as machining out the cavities in two blocks of aluminum. There are also bladders and foam inserts needed for the interior spaces. Then sometimes geometry has to be changed in order eliminate wrinkles and voids, or facilitate de-molding. With all the hand-work and time involved, its a lot up-front to develop. Also, every carbon part is paired by a few trash cans full of waste material (bladders, breather cloth, tape, etc...). Aluminum machining just leaves behind chips for the recycler and some coolant.
Making traditional tubular frames requires that you either use off-the-shelf tubes, or pay for the tooling to draw and hydroform custom ones. By contrast, aluminum welding and CNC machining are two very well understood and easy to control processes that require no special tooling. It also gives engineers ultimate freedom over wall thickness and tubing sizes.
Bonding aluminum, like in the Pole Machine, is strong, but the process is hard to control perfectly, and the end result has a finite lifetime. Welding, on the other hand, is even stronger and lasts for the life of the base material (given proper post-heat treatment).
  • 8 0
 @Noeserd: usually the metal material used for the mold is very expensive. Especially in a large enough chunk to do a frame. The mold has to have the same thermal coefficient so the mold and the part can expand and contract at a close enough rate during fabrication.
  • 6 0
 @Thirty3: I would assume that's what they're alluding to when they say "As we are starting our production facility with the targets of setting up new manufacturing processes, being able to CNC and weld alloy are a small part of what we need to achieve."

They're getting dialed on their CNC equipment so they can start producing molds. And they're figuring out geo so when they do make molds, they make it right.
  • 9 1
 @Thirty3: not the same at all. A mold has to be finished perfectly to avoid damaging the carbon and coat, and resist a big number of times, plus a mold is not just a cnc piece. It has also systems to close and open, to vacuum and to be handled.
It's clearly not the same thing nor the same job
  • 6 7
 But is this better then what the Athertons are doing
  • 2 0
 @toast2266: i think you nailed it
  • 3 0
 @splsce: good question
  • 2 0
 @splsce: Yeah, the Atherton frames use pre made mass produced carbon tubes between the lugs. That’s much less labour intensive than a full frame.

For this CNC’d frame from an environmental perspective, metal is better than carbon, because carbon is just reinforced plastic. Aluminium is very easy to recycle.
  • 4 1
 I still don't see the need for CNCing aluminum. While ugly, the Nicolai/Geometron bikes perform amazing, and you can prototype different geometries way easy with tubing. I guess we wouldn't be reading about this or talking about it if it was just welded tubes....
  • 1 2
 @uribefache: it would be a greater work of art if they fillet braised the join instead of welding it. The weld just looks so clunky against that beautiful machining. I used to own a Cannondale hardtail frame that was Fillet braised, was a real thing of beauty.
  • 2 0
 @RossD123: Not an expert but that would have to be a very delicate and precise machining operation. And while the dimensions might approach a butted tube, the material properties would not.
  • 1 4
 @toast2266: this CNC frame is almost the exact same process as making a carbon mould, you'd need the same machine time and programming for each iteration. Probably similar amounts of waste too. Neither is particularly efficient and tubes are always going to be more econmical (if thats your priority)
  • 1 0
 @Noeserd: They aren't.
  • 9 0
 @landscapeben: technically those Cannondale frames weren't fillet brazed. Fillet brazing primarily references joining steel tubes with a brass filler which is generally then filed down. Those Cannondales were welded and then the joins filed smooth. Similar effect in the end but very different processes.
  • 1 0
 @blanc: good point, I’m curious about the recyclable “revved” carbon from GG in that application
  • 1 0
 Do companies have just one mold for each frame size and model? Seems like production would be incredibly slow if they do.
  • 1 0
 @als802: Depends on the size of the production run. Generally there are a few copies of each depending on the size of your facility. Otherwise, yeah, it'd be a real slow day in the bike factory.
  • 2 0
 Something something "...man with a CNC machine, everything looks like an un-milled billet"?
  • 1 1
 CNC is the most reliable manufacturing method, as it has way less human interaction. Carbon is the least reliable since most carbon frames out there are made by hand. That and if you ever need a replacement part, its viable for a company to just fire up the CNC, mill out the part and send it your way, with the cost of only material and minimal labor, and that can be for bikes that are currently not in production anymore.
  • 3 0
 @Jhall303: Love reading pb comments for the interesting knowledge like this.
  • 2 0
 @Jhall303: woah, too much see thru didgeridoo
  • 1 0
 @toast2266: The real issue with carbon is not the mould. The real skill with carbon is the layup and using the right sort of carbon in the right place in the right layup to get the desired characteristics. That’s where the real skill and engineering is and that’s what take the time if it is done properly. Machining an aluminum bike is realatively easy and there are a lot of people with the knowledge of wall thicknesses etc
  • 1 0
 @alexsin: Huh! Well I live and learn, thanks for explaining that to me, genuinely appreciated Beer
  • 1 0
 @Noeserd: Anything you either make money off, or have fun with are more expensive. You're not just buying the thing, you're also buying a livelihood, and/or happiness too. Capitalism at it's finest.
  • 2 0
 I will never own a carbon mtb. Far too many jagged rocks where I ride, I've seen my mates carbon bikes get eaten where trusty metal just gets scratched and dented. Cracks me up seeing people wrap their precious frames, I beat the crap out of my stuff.
  • 1 0
 @uribefache: MARICA
  • 2 0
 I don’t see any advantages to carbon frames at all. What advantages does it have over aluminium? It’s generally slightly lighter and that’s it. Aluminium’s cheaper, stronger, more durable has better resale value, has a better feel than carbon and can be recycled. Honestly carbon only exists so the bike industry can extort an extra grand out of people by tricking them into buying a plastic frame made on the cheap by slaves in China.
  • 3 0
 @thenotoriousmic: while there is some truth in your statement, that is for a more appropriate forum not so bike related, but aluminum get's brittle over time, so it a has a limited lifespan.
  • 3 0
 @justinc5716: Additionally, aluminum frames will likely require forged parts as well, dropouts, yokes, shock mounts, etc as well as all the tools to check frame alignment. The costs upfront for an aluminum frame can be close to that of carbon.

The real cost savings for aluminum vs carbon happens once you go into production. The materials and labor are just cheaper. Even with CNC you can see the PP has forged links and dropouts. But otherwise it's just three processes, mill 2 halves, weld, and assemble.
  • 2 0
 @thenotoriousmic: Carbon is dramatically lighter, and when done correctly (BMC comes to mind) is more durable. You can't just cherry pick data, or I would show you that pretty much every single kona supreme from a decade ago snapped, and then conclude (wrongly) that aluminum is not suitable for mountain biking. The same can be said for ride quality- well designed carbon rides very, very good.
  • 1 0
 @morewhitenoise: Tubes are probably more economical if the frame design is simple. Looking at this bike, it's anything but simple. I would guess that having the entire frame CNC helps to make the process more simple. I can't imagine how difficult it would be to build that whole bike with tubes. You would have to deal with a lot of Heat from the welds, distortion, and you would probably still have to CNC a ton of pieces to make the tube welding possible. This is probably the easiest fastest way to create a prototype.
  • 2 0
 Some of the answers are really mind blowing ...
Carbon fiber bikes are more expensive because of the cost of the mold (which must be cnc machined) even if less resistance is required to this mold compared to forging, so maybe no’s that much expensive
Also this is a difficult material to work and requires to be worked by hands to do the junctions between the two sides of the frame
For metals , most of the times , pipes are made by rolling , which creates a better mechanical characteristics as the fibers of the metal are concentrated, while when you machine with CNC on a big bloc , you just cut the fibers.
Also CNC involves most of the times lots of waste as most of the material from the original block is machined , and can generate costs
Forging is the manufacturing process that gives the best mechanical properties as it keeps all the material fibers , so basically , for instance for a pair of pedals , CNC doesn’t mean anything, and it would be ridiculous to prefer it over forged pedals
  • 1 1
 @hamncheez: not true, my mate Josh a 200lb mx racer / stunt rider trashed the living daylights out of the originally blue and white operator for over 6 years and never broke it.

That’s the thing though, finding high quality carbon in the bike industry is like finding chicken teeth. Take most carbon frames to Mclaren or someone like that and they’d just laugh at you. It’s the lowest possible grade of carbon built cheaply in China and that’s why it performs so badly compared to alloy at least with alloy you’re getting premium materials. I’m sure carbon done correctly could outperform alloy if you spend enough money but we’re not seeing that currently with these cheap carbon frames.
  • 2 0
 @thenotoriousmic: I can second this as I work for an aerospace company that has very tightly controlled carbon fiber manufacturing processes. Once I brought in a broken part from one of my frames to one of our manufacturing engineers. He said it suffered from poor consolidation of the laminate (not enough pressure applied during molding), and porosity. It would have been thrown in the bin if it had come out of our factory.
That being said, the raw materials are pretty much the same. The difference comes down to manufacturing controls and tolerances, where the bike industry is woefully behind aerospace (perhaps understandably) and likely behind automotive (any auto engineers out there wanna comment?).
  • 1 1
 @justinc5716: Exactly and then ask how much it would cost to make a bicycle frame to their standards. Carbon is a con.
  • 29 8
 Need to sort out them welds, not the cleanest welds ever... Considering the whole frame is CNC, best off getting a top class welder to put the two halves together. Other than that though looks pretty well made.
  • 22 1
 That welder... for sure... lied on his resume.
  • 6 4
 @LucaP: but you know Pinkbike...always downvoted for stating the truth XD
  • 2 0
 Even some shallow spots. Yikes.
  • 2 0
 @mkpfaff: $15 an hour welder vs a $50 hour welder.
  • 14 1
 Go have a look at the welds on your car/truck/motorcycle frame.
  • 3 0
 Should really be robotically welded to stack the puddles perfect or get a clean straight bead. use a robot to cut it, use a robot to weld it...
  • 2 1
 @emptybe-er: but they are purely structural, this a frame they have gone to the extent of cnc'ing it for aesthetics with no performance advantage over any other frame, they are clearly visible throughout the whole frame...so if you are going to put that much effort, time and money in at least get the welds on point to, there is little spots on there that even look cold welded.
  • 5 0
 @LucaP: Orange finally gave him the boot.
  • 2 0
 @Danzzz88: I see your point. Side note though, I think these cnc’d frames probably serve more than solely aesthetic purpose. Moving welds away from stress-concentrated areas makes a lot of sense.
  • 1 0
 @Taildragger: This.

@emptybe-er: Very true; but, ugly beads are one thing. Im fine with that. If your not getting proper penetration like on the back end of that top tube, take it back to the kitchen.

This is a boutique race frame! Cmon. I have CC students that could call that out.
  • 2 0
 @emptybe-er: Bought an Harley few years back, I was shocked by the welds vs the price I paid.
  • 1 0
 @inonyme: I just watched a vid showing the inside of a rolls royce turbo prop engine. 4k hp and the main thrust bearing’s aluminum housing had bird shit looking welds. Not pretty but they held up just fine.
  • 7 0
 @inonyme: How can anyone be shocked at the value/price paid on a Harley? You pay for the name/image, they are the most over priced under performing motorcycle on the road...
  • 1 0
 @emptybe-er: Comparing robot GMAW welds on a steel trellis frame or sheetmetal unibody to a TIG weld on machine-porn aluminum bike frame is hardly fair. Those welds are trash by any bike frame standard. To top it off those welds are far easier to make than your typical aluminum bike frame as they're quite straight. TIG welding small diameter tubing like is the case in any traditional frame is far more difficult as your torch angle and feed hand position have to constantly match the tangent angle to the tubing.
  • 1 0
 @maxxx: yeah I get it’s not apples to apples aesthetically speaking. However, this bike was built for R&D, it’s used for testing and the welds aren’t perfect, so what?
Immaculate welds are a waste of time and resources on a project like this; if it was a production prototype to show off I’m sure the welding would be more aesthetically pleasing.
  • 1 0
 @emptybe-er: You're not wrong, but for all that's gone into the machining, its a shame not to seek out a welder who can lay down some consistently decent looking welds. Myself and other hobby TIG welder friends could have done a better (looking) job.
  • 20 0
 Imagine cleaning the dirt out of those crevices. Bit of a busman's holiday for the dentists
  • 19 0
 Prototype? Sounds perfect to send in for a field test.
  • 5 0
 That’s what Pole would do.
  • 12 3
 Can someone point me to the privee?

I'll see myself out.
  • 10 2
 I just cringed whilst scoping the top tube... oof!
  • 6 1
 I agree with the general skeptism on this construction method for anything other, and even, prototyping... But this thing has fantastic lines. Just one of those bikes that looks fast standing still.
  • 3 0
 I read stuff similar to this from time to time "Apparently the brand would have been willing to go back to the drawing board if the Brigade riders weren't happy about the performance," and wonder exactly how the riders feel about it.
  • 4 0
 Any other machinists sick of the massive cusps, step down, ballnose finishing on flat surfaces & general poor finish on machined bike parts to "look CNC" ? Think Hope started the trend and seems to be contagious!
  • 2 0
 Thank you!!!! Scanning has a time and a place, but these days people seem to use it everywhere. And let’s not even get started on the cusps!!!!!
  • 4 1
 Stoked, so glad to see more development in Alloy. Have no desire to own a carbon bike, has no draw for me and have just seen too much carbon damage from transport and shuttling. Not really for me.
  • 3 1
 Sorry, buy I really don't get the extra complexity here. What's the point of being different in this case? And that megalong abrupt welds? Pole had a think with their assembly/glued thing but here...
  • 1 0
 Here we are, reading about it, hearing the name of a brand that hasn't even released a product around the tech.
  • 2 0
 Welds can create stress risers so moving the welds from highly stress concentrated areas to low and spreading that stress out is the idea.
  • 3 2
 "unveil a CNC'd aluminum"

Quit using an apostrophe where an "e" would do just fine. Past-tense of "CNC" is "CNCed". Apostrophes are for contractions and possessives.

Same with "spec'd" or the even worse "specc'd": it's "specced" or even just "specified"; or maybe "equipped" is better, until you guys turn it into "equip'd"...
  • 2 0
 I want to see a production privee steel downhill bike, shan no(insert numerical digit here), that would be a thing of beauty and going by the rider feedback on all of the shan no5 bikes it would be a weapon as well
  • 1 0
 Would be amazed if that bike came out straight considering the manufacturing process.

I'm surprised these bigger outfits aren't using AM junctions with welded tubes like what Sturdy cycles and Huhn cycles are doing: so much more accurate and significantly less wasteful both in energy and material terms (never will machining a whole frame out of a billet of virgin aluminium ever be considered environmentally friendly, probably not even compared to carbon moulded frames).

But if you want to replicate the look of a carbon monocoque frame in aluminium for a prototype without investing in stamping tools I guess this fits the bill-et.
  • 1 0
 Do you know what does into metal AM? It's not efficient or environmentally friendly & 100% of the swarf from machining will be recycled.
Neither make any sense for any kind of volume and with DMLS/AM Metal / what ever you want to call it, if you can make it any other way, then you should - from a cost prospective. Only place for DMLS is producing parts which cannot be made any other way
  • 4 0
 good looking steed there mates.
  • 4 0
 I love being Privee to new designs!
  • 5 1
 That's what I like to see. Metal bikes with welds! Can't beat it!
  • 4 0
 Like the old school Cannondale bikes? Beefy beautiful welding
  • 2 0
 @splsce: Or even better, the Ventana welds.
  • 2 1
 Sad to see all that wasted potential all thanks to poor welding. It’s covered in undercut and craters from not ending the weld properly. Looks like an apprentice welded it or maybe the machinist.
  • 1 0
 Raw finish. Its single pivot. Looks like you might get a bottle in main frame and it probably has enough seat tube to fit a 125mm dropper. What's not to like?

I'm expecting some backlash here...
  • 2 0
 (Seinfeld; Kenny Rodgers Chicken episode) Kramer; ... Kenny? ....Kenny?.................Kenny?
  • 2 0
 But it doesnt carry a water bottle.
  • 2 0
 Production Privee bikes always look like works of art to me.
  • 2 1
 I like PP as a company and I liked the Shan GT i owned. But this is fugly, sorry.
  • 1 0
 I agree, but will be down-voted. I don't like the way CNC'd bikes look and especially with that huge non-uniform weld down the middle of everything. Has sort of a homemade feel to it, even though that's far from the case.
  • 1 1
 Ok here’s the deal. I came here to say “looks like a session” but decided I’m more mature then that.

Looks like a stump jumper!
  • 1 0
 That didn’t feel right.

LOOKS LIKE A SESSION!! Wooooooo

Ah there we go!
  • 1 0
 Can we please stop using "CNC" like it's some impressive new technology? Just say it's machined goddamnit.
  • 2 1
 stumpy don't drink that glass of liquid mercury... too late.
  • 1 1
 is this what happened when stumpjumper and knolly suspension got welded ???
  • 1 0
 It clear that's a 27.5 lower... Not lot of clearance ahaha
  • 1 2
 I'd think it was cool if it was 100% CNC'd with little or no welds, otherwise its just a longer route to the same destination...
  • 2 1
 Those swirls give me the creeps
  • 2 0
 I'd ride it
  • 1 1
 Seems like an unnecessary amount of welds compared to building it traditionally
  • 1 0
 I see the 2019 raw silver stumpy evo every time.
  • 1 0
 2008 called. Want their head tube angle back.
  • 1 0
 Prototype Suntour coil shock?
  • 1 0
 Yes, it will coming soon... said SRS on insta. I think it is more interesting to look at the tire clearence of the SRS RUX! Holy S***! its a 29er in a 27.5 fork?
  • 1 0
 @biketiff: I thought the same, pretty crazy that they can fit a 29er wheel in there just like there. From the side, tire clearance looks very snug though.
  • 1 0
 Tire clearance of the RUX Big Grin WTF?
  • 1 2
 Looks nice but if it’s like any of the other PP stuff there’ll never be any stock...
  • 1 2
 thats just a more complicated diamondback DB8. same linkage design single pivot. i was expecting more
  • 1 0
 That's allot of gooch.
  • 5 5
 looks like a stumpjumper
  • 1 3
 That's a lot of pivots for a single pivot.
  • 2 4
 Stumpjumper on steroids
Below threshold threads are hidden

Post a Comment



Copyright © 2000 - 2021. Pinkbike.com. All rights reserved.
dv56 0.016241
Mobile Version of Website