The Vulcain Cycles Magma Isn't Another Single Pivot Steel Bike
We first featured Vulcain Cycles in our 'Boutique European Downhill Bikes that Dare to be Different' article in 2019. The project is the brainchild of Julien Verbicaro, a former World Cup junior racer who went off to study mechanical design, started his own bike company at the age of 25 and designed and built the Magma downhill bike in Auvergne, France. Since that article, he's been testing his bike alongside a test rider and ensuring it is refined and ready for production.
Vulcain Magma Details
Intended Use: Downhill
Frame Material: Steel (aluminium rocker)
Travel: 200mm
Head Tube Angle 63.5°
Sizes: Custom (450mm reach pictured)
Weight: 16.75kg (no pedals)
More info: vulcain-cycles.fr
Intended Use: Downhill
Frame Material: Steel (aluminium rocker)
Travel: 200mm
Head Tube Angle 63.5°
Sizes: Custom (450mm reach pictured)
Weight: 16.75kg (no pedals)
More info: vulcain-cycles.fr
Julien has been through 4 further prototype stages since we first featured his bike in 2019.
While the new version of this bike doesn't look significantly different from the one posted two years ago, there are some crucial changes that Julien has been working on to improve on his first design. The first prototype ran on 27.5" front and rear but downhill design has moved on since then and the Magma is now designed around a mullet set up. The other change comes in the materials used. The front triangle on the production bikes will be built from Reynolds 921 and the aluminium rocker has been redesigned to be lighter and stiffer.
Reynolds tubing of various shapes and sizes is the bread and butter of many a steel frame fabricator
Julien uses Reynolds 921 for the front triangle and 853 for the swingarm
The thing that first drew our attention to this bike was the fact that it wasn't simply another cookie-cutter steel single pivot that you see in a lot of steel bikes. The four-bar design remains in this bike, but it has also undergone some revisions to prepare the bike for launch. The 3D printed parts needed to get the correct shapes are now 3D printed from 15CDV6 and the lower bracket is aluminum and now bolted on to the frame so it can be changed to accommodate metric or imperial sized shocks. The final refinements came in the form of improving the tire and chain clearance and reducing the machining for complex parts.
3D printed parts finish the frame off and allow Julien to design a four-bar system.
One of the advantages of Julien's small and in-house operation is that he can design the geometry of the bike to suit each customer. Some numbers are fixed, such as a 63.5° head tube angle, 438mm chainstays and 74° seat tube angle, but the rest can be decided by the customer when they order their frame. More info on the geometry options can be found here.
The production model will have a few further changes including black anodisation on the aluminum parts and a bolted, not welded, lower shock bracket.
Julien's propensity for the raw metal aesthetic goes as far as this crankset from Hope and braided hoses.
Julien has big plans for Vulcain and won't be stopping with this downhill frame. Next up will be a 160mm enduro bike that will be closely related to the Magma but with some tweaks to the kinematic for a more efficient pedalling platform. After that Julien will be starting to bulk out his range with an all-mountain bike, a hardtail, a dirt jump bike and an eMTB. He is also pulling together some budget to try and race the Magma on the World Cup circuit with a race team.
Magma frames start from €3,099 and are available via a Kickstarter now for a reduced price of €2,699, here.
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Maybe because it's a horst link?
In all seriousness, it's beautiful!
Just curious about why the lower pivot wasn't made out of a single yoke or the NDS dropout having an integrated braketab? Being 3d printed and all, it would seem cleaner and easier for production/alignment... I guess this is a prototype anywaysand trying to keep cost down.
-the Brits
Looking forward to seeing the 160mm bike you`re working on.
I`m a steel lover - aggro hardtail junky - and thinking about a full suspension machine in a near future to replace my quite obsolete Slayer SXC.
Stanton, Cotic, Starling and so on do great bikes, but if I can get such a wonder made in Auvergne...
I`ll probably get in touch with you one of these days
Cheers mec!!!
(where my fluids people at?)
Represent!
Nothing but respect for all these folks.
*OK, mine would be poorly designed, yet somehow still cookie-cutter hard-tails with questionable weld-strength that not even my family would like. And I would be surprised when I lost my shirt on the operation.
921 is stainless... Already decided to make that drastic of a material change without a prototype?
Not really the same as Starling.
Rest of the geometry parameters like chainstay and Headtube angle are locked to ensure a perfect behavior, in the way we have designed for it, whatever your size.
If we allow to change these parameters, we also take the risk to haves bikes that don't have a proper riding behavior between a small frame and a bigger one
It's not like I'd buy one anyway, so my opinion is even more worthless.
This to me is going backwards.
Straight down tube, not curved at the head tube junction.
Top tube and down tube are not welded together before joining the head tube, this is where the older bikes all cracked.
Pivot hardware looks tiny.
If you want to spend your money on this, go for it.
I wouldn’t touch this with a ten foot pole.
Do I have any idea if the material choice has any effect on your point? Nope. Is this the internet making me feel empowered to engage in conversations about which I know less than nothing? Yup.
The design you seeing there are for the prototype frames, final design will have proper bended tubing, with a tube that make support between the down and top tube.
All bike doesn't need to have tube joined, like steel frame, which have higher strenght than a alloy one. They doesn't need enough reinforcement, particulary after many FEA test that's saying there is no problem with 500kg of charge on it
Pivot hardware was already improved on final design, stiffe, stronger, and never crack in two years of hard test conditions with the old design.
cheer
I just don't understand this stuff. Why would i want a lower performing product, that's heavier and costs more?
How do you know it's lower performing?
Ok the price is higher than the other but steel frame is here to stand 3 times longer at least than an aluminium one.
I'm not here to say the magma is the best, but i really think it's a good one at least, or better than the actual offer we have
Steel is far less durable than carbon and unlike carbon is almost impossible to repair.
I have a welding ticket. I know a few things about steel.
The raw frame is beautiful without paint - sort of like if Dangerholm branched out from carbon into steel.
I'm not knocking your acumen as a welder or your claim that carbon can be repaired, but the claim that steel is almost impossible to repair is begging for some clarification.