A brilliant, interconnected suspension design that even used tuned mass damping! Buy the book here - www.amazon.com/Car-Suspension... (or from Amazon in your country)
Back when I was a mischievous student, we spent an interesting afternoon in a local carpark, trying to make a turn a 2CV over by stupid driving - we failed completely! What a machine!
The 2cv... my first car. Not ashamed to say that there where big tears dripping from my eyes when it was strapped to the truck in 2001 for its final voyage.
I avoided those dreaded tears by hanging on to it. Bought as a student in 96, but alas 2012 put in storage till I'm finished restoring another car. It served me as my daily and I drove throughtout Europe with it. Fondest memories!
I feel your pain deeply. I got my van from my dad for the princely sum of £250 in '92. I thrashed it for 4 years, going everywhere and using as a courier wagon in London. Then it failed the mot and needed welding on the chassis that I couldn't afford. It wasn't in anything like good condition so the truck came... now I wish that truck would return with its cargo.
This isn't just a highly informative video about the 2CV suspension, it's an object lesson on how to construct an educational video. Succinct and with visuals that illuminate the narration beautifully. A BIG hat tip to you!
Hi Julian. Great video, . You don't mention that you can raise or lower the ground clearance, front or rear, with a few turns of a spanner. I usually gave a good ground clearance on my 2CV's as I drove a lot on mud (and I mean MUD) roads. I was head of Quality control of the assembly plant here in Argentina. We did some quite interesting test projects - a water cooled engine and also a four wheel drive model. The latter was done by lengthening the main shaft of the gear box and coupling it to a second, inverted box at the rear of the car. You could almost climb up a wall with this one! Thanks again for your video.
My first car was a 2CV. Drove it for 10 years and then in more modern cars (boring) the next two decades. Now I'm back behind the wheel in a beautifully restored, light blue 2CV. And now it's fun to drive again.
Had three in a row before upgrading to the DS. Together those 3 2cvs brought me around 500.000 km through all of Europe and beyond in the eighties - including as nice side trips as journeys to the Turkish-Iranian border, to Crimea via Romania and Moldavia, to Mauritania via Tarifa-Tanger, to the Nord-Kapp and Ireland via Man (the Isle of). Never ever broke down needing anybody's help all those years and kilometers. Could not say that for any other cars I had, even with the DS being pretty reliable, too.
And the Citroen Xantia was the total opposite regarding roll angles. Almost none! Still holding the world record in the "moose test". en.wikipedia.org/wiki/Moose_test#Current_champions
Yes the 2CV is a milestone in car engineering: A 4seat, 4door saloon car weighing in at 500kg not been bettered since. Have to remember that the design and prototypes were completed by 1939, hidden from the occupation and served to restart post war Citroen, notable update: added one more headlight. Also of note that these "mass dampers" were banned from being used in F1 5years ago.
The mass dampers in F1 were a little different right? They used the momentum of a spinning weight on a thread to dampen the wheels if i'm not mistaken.
@@fergusoddjob Yes they were different in construction (weight and space constraint) but the principals are the same store energy of the wheel movement and use it to counteract the wheel movement.
A-series Citroen owner over 35 years, I still drive my 1974 Dyane daily (a really rare car now but basically completely the same as a 2CV mechanically), still yet to be surpassed in anything modern as far as off-road ability, comfort, simplicity and ruggedness (for a 600Kg car). I'm amazed it never caught on, imagine the packaging and space-saving possible today with a completely flat enclosed suspension system such as this but modernised. A legend.
ABS and ESP are legal requirements now in most countries. Unfortunately, making these work on a suspension like the 2CV would mean reinventing them completely as the car behaves completely differently than one on standard MacPherson and derivatives for which it was developed - eventhough the car's road holding capabilities make them pretty much useless. Also, tire sizes - this system works very well with small, light wheels : the heavier wheels we use now wouldn't work as well. Now, an electric car with a completely tuned electronic ABS/ESP system would make complete and perfect sense for this kind of system.
My mother had two Dyanes , both with the brilliant centrifugal clutches. Never, ever, went wrong and they were the best cars I have ever driven in my fifty-three years of driving. Astonishing engineering.
My driving instructor drove a nissan sunny, but my dad would give me the odd lesson in his Acadian van, a van version of the dyane, and boy the first time i went around a big roundabout i felt all at sea! I passed and he sold it to me for a pittance. Later, when I was really dialed in with it my mate was following me in his E30 325i sport on the eastern perimeter road at Heathrow (when concord used to cross it) and I hammered it over a couple of biggish roundabouts and a few straights. When we got to the lights at the other end, my mate was shaking his head. He couldn't catch me and said the tires were squealing. Yes, these cars might roll about but they held the road well. And being able to go virtually anywhere made it truly versatile.
You are so right. But the general public, nor the motoring journalists never understood the greatness of Citroen technology. Be it the 2CV or the fantastic DS.
Long time ago, I visited Paris. One day, I saw a 2 CV driving on a street covered with cobblestones. The wheels were dancing up and down, but the car was floating like nothing I have never seen before.
I think Citröen invented the diagonal meshing cog wheel which is what the logo is based on. The gear leaver was like the handle of an umbrella and came horizontally out of the dashboard. The A/C were two flaps under the windscreen that you turned a knob to open and let the outside air in. It had no petrol gauge other than a yard long dip stick like you have for your oil. Both headlights were mounted on a pipe which you could rotate by turning another knob, this was your dipped headlights. I was stopped by the police once and accused of speeding, I said "in this?" and they wandered off. Just so much fun to drive.
It wasn't a dip stick but a long piece of leather the headlights were dipped in the same way as to day just with s switch. You gout adjust the headlights depending on the load of the car! Notice that you only had a small speedometer with cable was also used to power the windscreen wipers! This car was so amazing to me that a drove Citroens ever since.
You just had a different model. Mine had a dipstick not a piece of leather. There was a knob on the dashboard that turned a cable that had a worm screw at the end, this turned a cog on the bar that held the headlights.@@51bikerboy
Yep I owned a 2CV for quite a while in the 70's. It was a great little innovative car, I realized at the time what a great suspension system it had, the little 602 CC flat twin engine never let me down. Yeah it was a little slow on acceleration but would do its max speed of 73 mph all day and sip gas while doing it. I guess my only complaint was that it was rather flimsy. Loved it though, had a great roll back sunroof too. These were cars that had character not like the dull boxes we call cars today.
I used to spanner for a 24 hour 2CV race race team. Yes, there is a race series for these! It's the slowest race you'll ever see but so much fun to watch. All the 2CV's had their suspension lowered, which also took out some of the roll. They ran a slightly wider tyre too (145 x 15 instead of the standard 125 x 15). I used to hate these cars until I got involved with the races, now I love their simplicity and admire the engineering that went into them. Truly a great car!
The 2CV was my first car for 10 years and 360.000 km.... crossing western Europe than as a one man RV....and it never fails. A special feature of this suspension was: you could simply get more ground clearance by turning a screw at each of the 4 horizontal hubs.
Before I ever drove a 2CV I was a passenger in a Mehari which weighed even less. We were heading out onto a city road being repaved, traffic maintained. Ruts, dips, raised castings all had me braced to have my teeth rattled loose & compressed vertebrae. Well. It was velvety smooth! Noisy yes. Sublime smoothness that was incomprehensible to me based on past experience. That was about 45 minutes before my first drive in a used 1968 DS21. Mind blown that day on different levels. Nearly daily I still drive a very well worn ID19 in non winter weather. But that 2CV suspension was my first exposure to the parallel universe of genuine Citroen engineering.
I love them! Once I challenged a cocky BMW-owner to a race. Only condition was I chose the track ... The 2CV did the stretch double as fast as the 3.23i !
I was able to take a 2CV to a slalom race one time several years back and it was an absolute blast. The audience was leaning in with the car, I could not stop laughing and it never under- or oversteered. No, I did not win but I had the best time of all of the competitants ;-). Also driving down a sidewalk barely even recognizing it amazed me. It drove me to Citroën, taking an ID19 out completely sold me and a lot of years later I bought a Citroën Xantia Break which I absolutely loved. Sold it last year due to a lot of bad luck in the last months with it (never the car's fault) and will never forget it. Luckily my parents could take over a Citroën CX Préstige from me and so I can still feel the absolutely mind boggling ingenuity of old Citroën every now and then and it all started with that hilarious 2CV ride.
I used to laugh at 2CV drivers, then I got a lift from a girl at work who drove one like a maniac. I'll never forget the thrill of bouncing around in that rattling tin can fearing for my life, I've wanted one ever since.
Great vid. Citroen should bring the 2 CV back!! If they could bring it in at an affordable price, it would be a hit!! I would definitely take a look at one. Will look for your book. Cheers!!
My dad built a few boogies out of 2CV frames. We've never seen anything eat up bumps offroad like that. It looked like a lizard, each leg moving independently. It was amazing
Found this very interesting, never been in one, back in the 70s when we all had our Escorts and Capris we use to call these motorised deck chairs how wrong we were
Drove 4 2CVs over many thousands of miles, on a poorly maintained British country backroad, you could set a pace which owners of larger more expensive cars were reluctant to risk their BMW etc, until the road climbed uphill !!!! Your description of the ride on a farm track reminds me of a lift i gave my brother in-law along a track which he had eased his own car - slowly..... Alarmed he asked how fast are you going? 30mph !!! No problem at all . One other unusual feature of the 2CV suspension is as it leans into a faster curve, its wheelbase alters. The compression of the suspension arms flattens the angle to the chassis. While the notable body lean lifts both inside arm pivots, shortening the inside wheelbase. Certainly a smoothly driven 2CV moving at speed (50+ mph) thru bends, just leaned and stuck to the road, on its narrow tyres. Superb packaging
I have seen these cars driving in films, and wondered why they looked so weird when they go over bumps, they self level as they go forward! This explains everything!
This is really interesting. Always loved the 2CV's and the last time we were in France there was still quite a few getting around. Never knew about that suspension, amazing.
The seats are made of several layers of canvas, stretched by rubber bands. The comfort is fabulous. The benches can easily be taken out to enjoy the evening around the fire. We went all the way to the polar circle to see the midnight sun while camping at 4, our first car trip!. From Lyon to Bodø (Norway) and back, 6500 km in 2 months. We only had 2 problems that we fixed with the tools provided. It's the only car I really regret! I've often gone to the mountains with her, the steep slopes don't scare her and she's very docile on the snow, if you don't go up, you go in reverse and you're fine!
Your fascination with the topic is super infectious. I’m not really a book person, but watching this video was a ton of fun, so i’m probably going to watch more. On the topic of tuned mass dampers: The channel practical engineering has a great video on what they are and how they work.
Nicely explained Julian. It baffles me why the logic behind the 2cv suspension has not been applied to the UTV/ATV market. As far as I have been able to find the A series citroens are the only production vehicles to use tmds and leading arm front suspension. I wonder why? Howarth's Africar tried to reapply the logic. Hydro-elastic/gas applied the interconnected front to rear. But the whole package of leading/trailing arm, addressing the high frequency and low frequency damping seperately, and interconnecting front to rear remains a the exclusive territory of the A series. I still dream of changing that ... But too busy farming at the moment. However my air suspension and tmd ideas continue to develope. Somewhat influenced by your rolling air spring fizzy pop bottle accumulator from a decade or so ago too! ;-)
I don't think it would work well for ATVs at all. The trick with linking the suspensions is that the whole car basically sits on an inverted pendulum. That's great in the sense that torque induced by bumps doesn't pitch the car, but it also means any torque directly acting on the body causes much _stronger_ pitching than with independent suspension. Specifically, acceleration buck and brake dive. That doesn't really matter for a car as weakly powered as the 2CV, but it would be painful too dangerous for a vehicle with high center of mass and short wheelbase like an ATV, used in steep terrain.
@@leftaroundabout kind of... But with the leading and trailing arms, it anti dive and anti squat. Anyway it has bugged me so much I am now building an SJ 413 with interlinked suspension as bit of a play to see how it turns out.
Fascinating explanation of the suspension of my 2CV6s which have shock absorbers replacing the friction dampers. A little firmer than the earlier design. 45 years of 2CV6 addiction in Australia and 550,000 kms. More Smiles per Mile.... Yippee
An incredible vehicle that I drove many tens of thousands of miles. On long drives it required competency to achieve momentum, but its ride on rough dirt roads was phenomenal. Everyone should be made to drive one as part of their driver training.
excellent tutorial. the 2cv is a great vehicle. simple and durable. long ago, I drove a 2cv in europe on a 3 day road trip. the first hour was a driver adjustment to the vehicle: it has quirks. but once adjusted, I loved the vehicle. I long for the simplicity of cars back then: nearly mechanical everything. I have wondered ever since if it could be modified and upgraded to meet today's standards (emission, safety, etc).
It is very nice that you pay attention to the special aspect of the 2CV. I drove it for years. I enjoyed it a lot. okay, it was noisy and slow, and when it rained it leaked here and there, not much but still. The crash safety was also not ideal. No power steering or braking assistance, so no car for the faint of heart. The car was also designed for farmers and they do have the necessary power. Now you are talking about the great suspension. But the engine was also very special. Its thoughtful simplicity is as amazing as its suspension. Perhaps you would also like to make a video about that which I will look forward to with joy. Driving in winter was a pleasure. The big wheels plowed through snow with the greatest of ease. Where other cars slid off the road, the 2CV just drove on. Transporting large items with it was easy. If it didn't go through the tailgate, you opened the roof. No space? Then you pulled the back seat out in no time. Hood, tailgate, doors were easy and quick to remove from the car. I have very fond memories of the time I drove it.
There was no way Chrysler could computer design a 2cv-copy...it appeared impossible!! They finally decided to import one and strip it completely to solve the mistery....this was more than 40 years after the 2cv was put on the market...... I worked on and drove a lot with 2cv’s....absolutely a fantastic design in every aspect not just the suspemsion....
I lived in Spain for 5 years and the Citroën was very popular. At first I thought there were serious suspension problems the way they moved and cornered. Never saw any ever flip over. I kinda liked the pick up truck version, highly useful.
Thanks Julian, very interesting to see this coupling of independant swing arms. I owned a Lexus LX470 for a while, the suspension was partially sprung and partially hydropneumatic. A great car to drive considering it was 2.5t.
I enjoyed the excitement and passion you talking with. This sheds the 2CV in a new light for me. I see some comparison with bicycles: my friends ride a full suspension mountainbike. I ride a Klunker (cruiser bike) without suspension, but with narrow rims and FAT 3.0 inch tires. No suspension needed ;) Thanks!
My dad owned a 2CV Special. He lives in the French mountains in Ardèche region. I remember we were passing everyone while driving mountain passes, uphill and downhill. It was GLUED to the ground. Totally amazing. A 500kgs 35hp race car was for sure!
La suspension des dernières 2cv special restait très souple, mais beaucoup moins que celle des premières 2cv. La dernière avait des amortisseurs à chaque roue au lieu des batteurs, les suspensions avant et arrière n'étaient plus connectées, et une barre anti-roulis avait été ajoutée. Heureusement car sinon en charge, elle aurait penché jusqu'en butée à des vitesses bien inférieures à celles que vous avez vécues, et son pare-choc avant aurait tapé le sol lors des freinages brutaux en charge (expérience vécue avec une 2cv de 1975).
Had a Dyane and 3 2CV’s when I was young. Having very little money to run a car at the time these were great cars if you were on a limited budget. Superb ride and comfort as stated, great mpg and very easy to work on. Back in the day there was actually 2CV racing !
Intriguing suspension. I recently designed a custom chassis, around the custom shape of a car design of mine. This almost reminds me of my chassis design
there is a 2CV museum locally where I live. There is a one off car where the owner made completely hydraulic suspension (back in the day, not recently) really cool and complicated.
I remember once having travelled as a passenger in a 2CV. It was a strange experience when the chassis went around the corner and the bodywork carried on straight ahead. Everything ended up going in the same direction in the end so no problem but it was an odd experience all the same.
Great design. Citroen have always been genius inventors in the automotive industry, BUT why hasn't this design survive the times and been used in most of the modern cars? Thank you :-).
The interconnection between the front and rear suspensions is good for grip but worsens pitching and front dive when braking. So much so that on the latest enand faster 2CV and Dyane, Citroën has removed this interconnection.
My Dyane (related design) was one of the most comfortable rides I've had. My current A Class, by contrast, rides like a bag of bits (though superb in many other respects). Interesting.
You know, I was thinking the other day if front to back connected suspension would make any sense since there arent any around and quickly concluded that it doesent make any sense. Really interesting.
It actually makes a massive amount of sense. You always have disbalances in the forces acting on wheels: you have heave, pitch, roll and warp events while you ride, and you can always make use of forces that act on one pair of wheels to counter the forces on the other pair, etc. You can google "fully dependent suspension" and "mode decoupled suspension" for more info; it's not used on road cars, but it's used in some racing prototypes.
Back in the day after the pub…..we held the unofficial lap-record around the Aviemore centre car park,complete with some of the first ever speed humps, 2CV with James Bond bullet hole stickers floated over the humps…….it was called the Yellow peril……two loony’s ,roof down in the snow…..great entertainment for all watching even the disco bouncers cheering us on…..happy daze 👍🚀
Just one thing to note about your drawn diagram. The spring are very close to each other inside the tube and don't have that big gap you showed. This helps with the loading/unloading and the inter-connection. Under heavy braking for instance the front spring compresses heavily, this then unloads the rear spring and the rear of the car goes down at the same time as the front lowering. All four wheels get planted in the tarmac and it really feels like that to the driver. Another reason why the braking is so good on these cars, less than 600Kg's, huge in-board discs, clever brake force distrubution and of course that inter-connection. They can really stop! even with no brake servo and zero electronics.
@@alaindumas1824Les toutes dernières 2cv avaient des disques à l'avant. Ces disques résistaient un peu mieux à l'échauffement, mais n'étaient pas tellement plus puissants.
It's the opposite. Compression from the front is transmitted to the rear and therefore lifts the rear. Under braking load the 2cv dives more than any other car.
@@HenriBourjade the dive (and squat under acceleration) is the direct consequence of low pitch stiffness, which is expressed as pitch natural frequency in this video.
Thanks for your explanation,which I agree 100% with!! But another big advantage of the suspension design is how it saves weight!! Very simply put you can compare a car with a bridge bridging the gap between rear and front suspension which normally is the distance between centre front axle to centre rear axle....now look at the 2cv; the forces of the front axle are offset apr 40cm to the back at the back offset 40cm to the front!! The ‘bridge’ only has to cover the gap between the pivotpoints of the suspension arms!! In front of the front tube just a very lightweight frame to carry engine and gearbox,behind the reartube even less weight just to carry fueltank and the luggage.....the passengerseats are located on top of the bridge....truly genious!! (until you get involved in an accident...) I remember a smal article in a Dutch car magazine in the 90’s: the Chrysler company in the USA was so puzzled/intigued by the low weight of the 2cv
Love the details in the design of the 2cv, from lawn-chair seating to basically being able to remove the entire bodywork with an adjustable spanner. Suck a knack for hilariously simple dirt-cheap solutions that work absolutely brilliant.
Never understood 2CV suspension before, I was a Xantia owner just for the incredible Hydropnuematic Citroen experience, what a car, proper French engineering, only beaten by the stunning XM...what a design.....buying the book
Carroll Smith's last book detailed the "perfect suspension" that interconnected diagonal dampers. I believe the McLaren MP4-12C uses something similar. Lotus developed an active suspension that used 50 hp to run. The system made it onto the 1989 GM CERV III concept car.
Remarkable choice to explain the handling of a bump starting with the rear axle. We usually drive forward, bumps hit the front suspension usually a little earlier than the rear….
It makes no difference whether it is the front or rear wheel that moves upwards over a bump: the wheel at the other end pushes downwards, reducing pitch.
@@JulianEdgar I understand that of course, it’s just a strange approach to how the car would encounter any bump. It’s an extra mental jump I had to make to follow your explanation.
Very nice Video thanks for that. In my student time I had 3 2 cv's, the first a 60 model, vith a 12 Hp 375 cm3 motor. That had the mentioned suspension with friction dampers asnd inertia dampers with the wheels. Later Citroen skipped this and mounted hydraulic dampers, but the earlier model had the best handling on rough roads. I crossed the highest pas in europe the Gross Glockner, with 3 persons and vacation luggage. We passed big Mercedes and "Yankers" boiling in the side, but the little engine tugged on , slowly but without stop. I later bought a 24 Hp with gearbox and installed in the old " 2 CV" what a speed monster😂 rounded 95 km/h, and topped 128 km/h with a special tehnic on the autobahn in Germany. We waited fore a big lorry, when he passed, we got in the slipstream and of we went., In this way we got a petrol consumption of 28 km/l!! Fantastic for 3 students with lean purses. Later I got a CX, and now a Citroen C5, fantastic cars with the Hydrapneumatic 3 + suspension, but sometimes I miss the old 2 CV's, their charm is fantastic
That bell crank arrangement is similar to what is used on many motorcycles with mono-shock absorbers. The also benefit that the amount of leverage on the spring changes as the crank moves.
Hadn't even finished watching to the end, but I felt compelled to start my comment; Excellent video for several important reasons. Just your style alone is great. The use of drawings, brings the visualization of the words right straight to understanding. Clear concise voice at a normal speed of words, I drop out if it takes a lot of effort to guess what was just said. Clever idea to have your presence (lower right) but not in the viewer's face plastered on the screen at arbitrary moments , like a game of 'peek-a-boo' . . . lol. That whole idea there brings the video itself to a feeling of an inter-office chat between two colleagues having a discussion on perhaps a collaboration of ideas on a given project. In your words 'brilliant' Finally, the subject (to me anyway) was compelling. Any design of complex mechanisms brought to such simplicity and economics is fascinating.
