Let's Talk Cyclecars

A good while ago I made a post to request information and comments on an unusual prototype here in this thread. Here it is:
http://www.jalopyjournal.com/forum/showthread.php?p=5553227&highlight=hinged frame#post5553227
Since then I've found a couple of links with a smattering of details, but no engineering drawings unfortunately:
http://www.flickr.com/photos/mrscharroo/6014628651/in/photostream
and
http://www.isetta-owners-club-gb.com/rare_7.htm
Although the Prvenac car is a bit larger than cyclecar dimensions, I thought its clever design might capture someone's imagination, as it has mine.
"So, what do you little maniacs want to do first?"
Zerk, Jul 24, 2012 Report​

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Hello Zerk,
and other interested!​

A few words about PRVENAC – could be translated as „The First-born (son)“, almost from the first hand! Trough long period, from early youth, I was interested in that micro-automobile (bubble-var), after I saw one not-so-good newspapers photo... Than, some 15 years ago I was positioned almost in the middle of history! I met one of the creators and son of another, got a lot of documents and fresh memories from the main actors. Than, being involved in lift industry (elevators), I became familiar with company “DAVID PAJIC – DAKA”, where Prvenac is produced in 1958... Because of my hobbies, I was connected with Institute for Engines and Engined Vehicles based at Faculty of Mechanical Engineering, as part of Belgrade's University – where all testing was done...
Next time about that story, but just a few sentences about Prvenac.
It was designed, constructed and tested as prototype for mass-produced “people-auto”, in a style of bubble-cars popular in Europe during years after WW2 period. There were negotiations with BMW, that failed: they didn't want competition for Isetta and even didn't want to sell components (engine and transmission). There were contacts with Yugoslavian industry, but nobody was seriously interested. Anyway, era of such micro-cars was near its end in Europe and they were replaced by small but real automobiles. Even in Serbia, started production of FIAT 600d under license, by factory ZASTAVA, later more known abroad by infamous business affair with selling YUGO in USA...
Therefore – everything was finished with this first prototype, that soon disappeared: probably that many components were removed (stolen), and the rest was sent to junk-yard... Only some curt-cases stayed for some time, about authorship, patents and intellectual-property rights.
Designed was the second prototype with more aerodynamic body of metal monocoque construction, with better suspension (coil-over-chock springs), better engine and transmission. Except small model for testing in air-tunnel, nothing was made. I still have blue-prints for that second prototype, got from than alive creator.
A copy from old newspaper is attached (the same one that started my occupation with Prvenac)...

Ciao, Zoran​

 

The newly protoed 'Elio' bears some resemblance to 'Sportsmen', and 'Super Modifieds', with its narrow 1 person width, center steering...2 occupant design places passenger behind the driver, maybe eligible for the Sturgis run. (wear proper attire...)

We have some open wheeled front suspension, (independent 'A' arms, ala 'Street Rod') and its center rear wheel seems to emulate an extreme narrowed rear, (just at a glance)

The 85 MPG ploy may be just the ticket for drafting some of the 'progressive types' into our fenderless circle...Get their feet wet...then pour 'em into a 'T' bucket.

 

I now have a Facebook page for the Jappic recreation

https://www.facebook.com/pages/Jappic-recreation/288202517984662

 

Saxon (Saxson) steering gear for sale on ebay - would be great for a cycle car build. Check out Model T Haven listings. It would be mine if it wasn't a left hander

 

Are you sure you can't disassemble and rotate the crenk 180?

 

I dont think so - I could fit the mounting bracket at right angles to the chassis rail or modify the mounting bracket - but I wouldn't want to limit its chances of one day finding its way back onto a Saxon.

 

I remember seeing lots of Zastava 600s when I was in Athens some years ago. It'd have been a relatively easy route to a diy 850TC if I'd had any money: rather appealing because my dad had had a slightly-Abarthized 600 before I was born.

 

Hello Ned,​

For some time, I didn't hear for once very popular term of "Abarthised" Fiat 600, or Zastava 750... For all of us born around middle of the century, Abarth was legend, no mater if auto was modified in some back-yard garage or bought as original in Italy... Having a lot of Zastava 750 around, the simplest way was to have "sport" auto (for races, rallies, show-offs...) was to buy some Abarth parts in Trieste: camshaft 013, double-carburetor, pistons, valves and springs, better exhaust... Than, appeared problems with non-adequate suspension, braking, steering - never end for modifications. Lucky guys, bought second-hand Abarth TC, or Corsa 850 imported and registered them somehow, and the luckiest bought new racing variants of 850 or 1000.

For other, there were possibility to buy Zastava 750 Special with 32 HP, or version with 850 cc and some 35-36 HP... they are still popular between enthusiasts, gathered around club "Nacinalna Klasa" (national class, as used once for racing class)... Some had autos tuned quite well, with engines up to 1000 cc, new MacPherson suspension at front, disk-brakes and so on... One guy made exact replica of Abarth 850 TC, buying all original parts. Experts say that it is as original car! Cost him up to 10,000 euros... Only “papers” are on Zastava 750 with 25 HP!

My late father had 3 zastava 750, in spite that could have bigger auto, but he like them and knew to repair them... The last of them I got after his death... I would be glad to have one again!

Ciao, Zoran​

 

PRVENAC – Part II.

In spite the fact that Prvenac was patented (after construction) and that I have great admiration for both authors and other involved, I often questioned myself, was it invention( new industrial project ~motored vehicle) at all:

1. diamond wheel layout was old more then half a century;
2. rear-wheel steering – tried before, as the main steering or in combination with front-wheel steering;
3. egg-shaped aerodynamic body wasn't new in 1958;
4. central-mounted engine with total weight distribution of around 25% on every of 4 wheels – tried successfully before;
5. motorcycle engine in small automobile – nothing new;
6. remote control for gear-box – quite extraordinary and probably the most problematic solution (more about hat later);
7. only suspension wasn't used on similar vehicles before, as I know!

So – about design, construction and work of suspension!

Ned Ludd was right and one of the rare persons that noticed that: Prvenac was practically double three-wheeler, with bases connected on the same middle axle where there were two powered wheels. Combination of tadpole three-wheeler (rear-wheel steering) and delta-trike (front-wheel steering) – good or bad? Probably that it had good and bad elements of both type vehicles, and some by its own. With light weight, small power and low speed, over bad roads of that period: nobody expect and need great performances and excellent road-holding... Probably that not one of bubble-cars had that?

All motored vehicles with three (or more axles) have strong strains on suspension and on chassis, some torsional, some longitudinal, some transverse – and combined... In the case of Prvenac, that is avoided by the fact that each axle is freely and elastically suspended at the ends of triangular (geometrically) frames, with vertically moving over the part of the circle of maximum radius. Long leaf springs positioned longitudinal and parallel to each other, are connected at the middle of the front and the rear frame, with chassis/body unit on them.

Moving of the axles is following:

1. the front axle (one wheel) could be lifted/descended at the end of the front frame (leading arms) with the center of rotation on the central axle (two wheels);
2. the middle axle (two drive-wheels, presented as rotary connection of the front and rear frame) could be lifted/descended with the center of rotation on the front axle;
3. the rear axle (one wheel) could be lifted/descended at the end of the rear frame (trailer arms) with the center of rotation on the central axle;

Although all 3 axles are connected in-to dependent-spring system, their movement is not interacting. Maybe something is lost in translation, but could be clear if I scan and post sketches from patent.

Attached are photos of diamond style automobiles, that are NOT as Prvenac, considering its special suspension... Maybe later some more text with photos and sketches.


Ciao, Zoran

P.S.: I finally found Tony Marshall, famous by his work dedicated to micro-cars (especially BMW Isetta), that was and still is interested in Prvenac... Therefore, I will send to him directly all the further information.

 

... and, a few more diamond-style automobiles, that are NOT prvenac!
Ciao, Zoran

 

I once had a Berkley, an 800 pound fiberglass two cylinder two cycle motorcycle engined car that powered the front wheels by chain drive. The car looked like a baby AC.

 

Hello,
A few sketches for better understanding of suspension and steering of micro-car PRVENAC!
Ciao, Zoran

 

... and, one more that was too big for the previous message!
Zoran

 

... and, a few photos of chassis that show better how Prvenac suspension work.
Ciao, Zoran

 

That is extremely interesting. There seem to be some clever pitch-rate shenanigans going on: that is a field of enquiry that has sadly been abandoned, now that the Enclosure of the global motor industry is complete.

I suspect that much the same benefit could be achieved in an apparently conventional format if each wheel in the diamond arrangement were replaced by an interconnected pair and, because the wheel movements at each corner are the same for one member of each of two pairs, those members in each case be reduced to one wheel, bringing us back to four wheels and not eight. My apologies if you are now completely confused But I've long been aware of the equivalency between interconnected suspension and diamond/combined-trike layouts.

 

Hello Ned,

In spite that I wasn't an engineer (or maybe because of that), it seems to me that I understood your explanation of possible solutions for interconnected suspension systems (cantilevered arms for axles?)...

When my son was a kid, he had small all-terrain loon-module, with such combinations of axles and double pair of wheels on each axle.... It was good for any kind of terrain, no mater how uneven and twisted it was (great toy for me!)... Later, I had small hand-masseur tool with even more wheels - similar results for all parts of body... At the end, Prevenac's system could be the simplest and still efficient?

If we could say "ordinary" diamond chassis layout wasn't forgotten, but with "normal" suspension... One variant had TRABANT engine/transmission and trans-axle with suspension for middle axle/wheels!

Ciao, Zoran

 

... and, a few more!
Zoran
P.S.: It seems that we are a little of topic: from the start - Prvenac wasn't cycle-car and all other shown not near to one?

 

... from me - the end with Prvenac, diamond/rhomboidal chasis and so on!
Ciao, Zoran

 

Alldays and Onions cycle Car?
I bought a bunch of alldays midget parts a week back and am thinking this could make a unique cycle car while I search for parts to built a veteran. Its about 1000cc 10hp water cooled originally conventional shaft drive - not bad for 1909. It is a nice compact light unit with ali crankcase.
I am thinking convert to chain drive, wooden chassis Jappic inspired with a good measure of steampunk. Apparently they were good hillclimbers in there day although that may have been the 1600cc - am still learning having exhausted the inter web rather quickly.

 

Hello Kume,
Really great veteran engine! Is it complete?
I suppose that it is twin-cylinder... Is that some kind of reduction transmission visible on the second photo?
I wish you joy and sucess in following work - keep us informed.
Ciao, Zoran

 

Thanks Zoran
Yes 2 cylinder - originally has cone clutch/flywheel with seperate gearbox and conventional rear on canter-levered springs. The chassis looks like a bed frame - very light angle iron and 1&1/2 inch pipe. Magneto ignition which is probably what you are referring to

Kume
is .

 

Nice engine. With chain drive that might be a good candidate for friction drive.

 

Hello Kume,​

Yeees - that must be transmission for magneto!
That Alldays was quite cute light car, similar to many European light class - voiturettes. They were ancestors of cycle-cars, but were traying to be more serious, like small but real autombiles. So, making cycle-car with that engine should be good way to use it. Jappic chassis is wonderful and Ade made it in magnificient way - but, it looks to me quite complicated? Maybe, something simpler as his Cahter-Lea, or Grafton...

Ciao, Zoran​

 

I agree with Motoklas, something closer to the Chater-Lea is more period-correct than the significantly later Jappic. Probably more usable, too.

 

Yes I quite agree - I guess I was referring more to the aesthetic of the jappic but yes the charter Lea is a more appropriate model or the anzani which also looks to have a light frame . I am thinking wooden frame with a canvas body with quarter eliptics all round and may have to employ a few austin seven running gear parts to get the Mk1 rolling.

 

Hello Kume,​

Of course - you could build everything that you want and that you can!
Wooden chassis and body frame with canvas over it - nice air-craft tradition!
Could be light, simle and cheap - but, nice looking... There are a lot of examples with cycle-cars built in such a way.

Ciao, Zoran​

 

Hello,
on my Youtube chanel Rosozo i have 4 videos when i was building my Salmson S4c Special.My next project will be a an aero engined racer with a Curtiss engine.

 

Hi Rolfzoller, and welcome!

If you like, please post some pictures of your Salmson on the Specials thread. I'm sure you'll also enjoy the Aero-Engined Vintage Racers thread. Enjoy!

 

[hello All, I have been trying to find some more info on this little beauty, can any one help???

 

That's a Panhard & Levassor "Sans Soupapes" badge. Indeed, a cursory search leads me to a publication of a Dutch Panhard club, which makes reference to the "Lame de Rasoir" (Razor-Blade), a record-attempt car with a 1½-litre four-cylinder sleeve-valve engine (p. 12). There was a 5½-litre version as well. Notable was the novel columnless steering system: the steering wheel was attached to a ring gear attached to a large centreless bearing that ran around the outside of the driver's legs. The aim was to reduce the frontal area, but the resulting driving position was apparently "extremely uncomfortable". In the interests of weight saving and aerodynamics the only brake it had was a single transmission brake, which must have been scary.

The 5½-litre version set a number of very short-lived speed records in 1926 at Monthléry, most notably the 5km at 139.2mph. The records fell to a British attempt shortly thereafter. A subsequent attempt to regain them resulted in the instant death of driver Marius Breton, after a blowout.

I can follow the Dutch of that article, but I lack the Spanish necessary to learn much more from this page. Some more pictures, though:









Marius Breton 1892-1926

According to the Dutch article the cars themselves have "gone up in smoke."

How did I do it? Spotting the PL badge helped, but mainly it was the Google search-by-image feature. It's extremely useful. Open a Google Image Search tab, go back to the tab with the page containing the image you're investigating. Click on the image, drag it first up to the Google tab and then down to the box that says "Drop image here." A wealth of info pertaining to that image comes up.