Some ideas make us wonder “that’s genius, why did no one think of it before?!”
With its simple technical innovation, this prototype made by Yoann Loncle (Menhir Cycles) and Joël Dunkl (DID) is a perfect example.
Interview with Joël, Dunkl Industry Design.
You say this is a bikepacking bike. It looks more like an enduro bike to me!
This is the bike Yoann and I have made for the Concours de Machines 2018, in Bruniquel, France. The theme that year was off-road adventure, camping out and self-sufficiency.
We noticed that most people only go bikepacking once or twice a year, for two months max. It is rarely a year-round activity… We thought that buying another bike just for that would made no sense, especially with all the bikes we already have in our garages!
I totally understand it cost us 2nd place at the contest: we were criticized for not sticking to specific bikepacking geometry, staying with a more traditional trail bike geometry.
That made perfect sense to us.
Why a hardtail ?
We definitely wanted to keep a suspension fork and a dropper post. The reason for this was, that when out bikepacking, we often come across some killer singletrack which would be an absolute blast on a more trail orientated bike. But on our bikepacking bikes, it is harder to maneuvre, throw in sweeping turns and get air…
Yoyo comes from BMX and I ride enduro. We both ride for the sensations of speed and changing terrain!
So we built a hardtail enduro bike with a bikepacking option instead of an enduro-capable bikepacking bike.
Concerning tires too, one can try to pollute less!
Running tubeless
– Prefer biodegradable sealant
– Pop tyres with a compressor or a tubeless-specific pump instead of a CO2 canister
Running tubes
–Fix flats with patches instead of disposing tubes
–Do not throw away old tubes, many associations collect and upcycle them!
-CO2 canisters -even though they are recyclable- are pricey and not eco-friendly.
A mini handpump will work as well!
What is this valve on the downtube?
The main idea was to put a pump inside the frame.
Yoyo -who has an ingineer education- said “Yeah but if we make a hole here, we’ll have to braze a stainless stiffener… It will be a pain, rust will get in, it’ll never work!”
So instead of putting a pump inside, we kept the pump on the outside and used the frame as an air tank.
We installed a valve that creates an air chamber inside the downtube and toptube, which are connected by a small tube inside the headtube. These are airtight welded to the seat tube and bottom bracket.
How high a pressure can it take? Don’t you fear it might explode?
We ran initial tests with good old construction site plumbing pipes that we brazed and put a valve on. We managed to fit a tubeless fatbike tyre with this set up! The test was a success, everybody in the workshop was euphoric!
We calculated the tube volume, the theorical pressure capacity this kind to structure can hold, which is 150 bars / 2175 PSI! (Should we find a powerful enough machine!)
We can inflate the frame up to 15b / 215PSI with a good floor pump. This is enough to inflate two 27.5*2.85 tyres at 1.7b / 25PSI.
It allows me to play with pressures, I can add some air when I’m back on tarmac.
The huge advantage of this system is that it doesn’t require taking the wheels off.
It is clean, easy and only takes a couple of seconds.
So I do not hesitate to reinflate, which minimizes punctures.
Are sensations different when the frame is inflated?
Honestly, handling remains the same.
Still, it is possible that the internal pressure makes the frame more shockproof, like a can when it is full or empty.
I have seen Yoyo bail heavily once or twice, and the bike was just fine, not even a ding!
As for ride handling, I think this bike is very playful but also very demanding.
It’s an education on every ride!
Joël's Menhir-DID
- Frame: Menhir Choka
- Fork: Rockshox Pike 130mm
- Handlebars: SQ Lab 12°
- Stem: Funn Funnduro
- Shifter: Sram GX
- Brakes: Shimano XTR
- Headset: Hope
- Saddle: Fabric Scoop Sport Radius
- Seatpost: KS Lev Integra
- Derailleur: Sram GX Eagle
- Tyres: Onza Canis 27.5*2.85
- Dynamo hub: Shutter Precision PD-8X
- Crankset: Sram XX1
- Bottom bracket: Wheels MFG
- Pedals: One Up Components
The integrated cathole shovel is a reference to framebuilder Matthieu Chollet, who has a titanium one.
Where does this collaboration with Menhir come from?
I met Yoann at the 2017 Concours de Machines, in Ambert, France. I was part of the technical commission.
When Yoann came with his bike, my first reaction was to say “how beautiful!”
Not Yoann, his bike!
I loved the choices he made about geometry and components… His bike was the only one with 27.5 wheels, Jones bar, MTB brakes, a 1* transmission and a big cassette.
I literally told him “Damn, I’d love to ride that bike at the contest!”
That’s what I did, and the route wasn’t gravel at all! It was muddy, singletracks ; an enduro motorbike had passed through 2-3 days before and it was full of ruts…
We got on well. We thought it would be cool to have a common project some day. When we read about the theme of the 2018 Concours, we immediately had lots of ideas for a bikepacking-oriented enduro bike.
Do you have other common projects with Yoann?
Of course! Actually, Menhir was in Rennes and he is moving to the North Valley, where I live.
So we will go on working together.
Will this bike remain a prototype?
Initially, it was only meant to be a showcase bike for the Concours de Machines.
Considering the interest it roused, we will launch a Kickstarter campaign to make a a number of frames which should be delivered in october, in time for the hardtail season.
Follow Joël Dunkl and Yoann Loncle on Instagram
More information: menhir-cycles.com
