BMW R12 vs Zundapp ks 600

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ssparatrooper
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Re: BMW R12 vs Zundapp ks 600

Post by ssparatrooper »

The R12 with its "lazy" engine LOL i have forgotten how many time these magical 600s are stuck in the mud wheelspinnig in a clockwise motion only to be passed by my faithfull old "Uschi"

i agree the 600 is a revvie engine but that will only work on tarmac that silly front fork they have on them makes riding solo an alien expierence, the foot gear change being the best thing (it feels more modern) the R12 is a plodder but a very smooth ride as a solo and feels responsive and will pull out of corners with ease, you cannot change gear as fast as on the zuendapp 600 because you have a hand change on the R12 like a car

I like the look of the 600 very art deco? but it has too many silly over engineered parts (wheel bolts for instance) needle roller crankshaft the stupid back to front battery, coil, lightmachine configuration means when the battery is dead it dont work and you cannot bump start it! the R12 works the other way round magneto to start the engine and a dynamo to charge the battery=allways works probably why mine was build in 39 and surrended in 45 at klagenfurt and still runs on the original clutch, pistons, magneto from the war!

it is by far the nicest bike i have ever had and coming from an ex racer of 250 aprillia missiles (proper ones not those silly suzuki engined turds) that is quite a comment, i would even like to plod it round brands or mallory just for a laugh! maybe one day LOL
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Enigma
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Re: BMW R12 vs Zundapp ks 600

Post by Enigma »

KS600 stuck in mud??? These bikes are very similar and even have the same 3,50 – 19 wheels. As far as I know the KS600 swept away all competition as a gespann and won the terrain races it competed in pre WW2. Even the 1000ccm category was won.

When it comes to alien experiences all theses museum pieces have some peculiarities. The front fork of the KS600 was changed as well as the frame after WW2. I simply love plate framed bikes and I know it is not the most comfortable way to travel. What worries me most are the brakes. The technical side is another question. The problems caused by over engineering are possible to fix like locking the wheel bolts. In the original manual it is stated that all the lubrication points should be filled with grease every 5000km and the “Vierkantschrauben von Zeit zu Zeit nachzuziehen”. If one bothers to tighten the wheel bolts on a regular basis they should do just fine.

The R12 is a design from 1929 and it works very well. Efficient at the job it was supposed to do. The lightmachine is a very nice but primitive way to live with faulty batteries. If you look on the post WW2 BMW designs their post WW2 design was a single block engine with a lot of similarities to the KS600. Including the electrical system. I once had a BMW /5 from 1973 and the engine had the same arrangement. Another factor one should bear in mind is that the electrical components are more than 60 years old and personally I will rebuild my KS600 to 12V and replace the electrical components with modern electronic devises that works better. The lightmachine on my R12 will only be renovated. Fortunately I have some NOS components if anything breaks down. In general the KS600 was a superbike when it came and it is true that crankshafts are a problem. (As they are on the R12. I had my R12 crankshaft renovated a Staschel Kurbelwellen in Bremerhafen where they have the original specifications bought from Hoeckle that made these crankshafts. )

When it comes to original parts my KS600 is now almost 100% original. Even the steel pannier bags are original. (Found one in a barn and another one on the garbage dump, lol.) The only missing parts are the rubber /steel spring handle that is on the back seat and the bicycle pump. What will be done now are technical modifications to the engine and replacing the interior components of the Kardan. I have decided for a rebuild despite the fact that I have NOS oversized 3.01mm needles for the crankshaft. The consequences of a breakdown might ruin the crankshaft completely.

When I got the KS600 the R12 kind of just faded away. A very well made bike but outclassed and outdated by the KS600. It might be that I go for a R75 Gespann instead as my next project.
Last edited by Enigma on Mon Dec 28, 2009 7:03 pm, edited 1 time in total.
schwarz engel
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Re: BMW R12 vs Zundapp ks 600

Post by schwarz engel »

as previous mentioned ss paratrooper , down to the the ability cross country of the krad handler , others are better than some! :D theres an interresting film on u tube under ss kradmong showing evan the big krads struggling! my engine is my weopon.
as prev mentioned by enigma the bmw design was pre 30,s production for the zundapp 600, 1938 to 1941.
both machines really were a civi bike but utilised because thats was all there was,good for western europe blitzkrieg , not so good for russland.
hence the wh identifying the krads shortfalls and initiating the design for the big boys both bmw and zundapp 750,s, a focused production run.
i know you know this just plonked it in for those who are are yet to experiance hot motors and cold feet!!and to experiance hanging over the seat changing a fuxxed plug
enigma i had a ks 750 that when inspected the rollars and krank were spot on , it was juli 43 krad but usually theyve seem to of had it.so basicaly if you plan to ride any krad on the road you are going to have to spend a serious amount of cash to upgrade your 70 year alte machine.
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Enigma
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Re: BMW R12 vs Zundapp ks 600

Post by Enigma »

Schwarz engel, you are indeed right. Both bikes are civilian machines pressed into service. The KS750/R75 was meant to replace them but as in all wars they stayed in service till the end. You are also right that old crankshafts might be OK. Mine is a borderline case concerning if it really needs to be renovated but I have decided to renovate this bike only once and to maintain it so that it will last at least my lifetime. I reckon between 1500 and 2500Euro’s will be the final price tag for the technical part.
ssparatrooper
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Re: BMW R12 vs Zundapp ks 600

Post by ssparatrooper »

well i must just be a nazi kenny roberts then!

:lol: and modest of course :roll:
ssparatrooper
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Re: BMW R12 vs Zundapp ks 600

Post by ssparatrooper »

one thing that would put a spanner in the works would be the cold in russia, batteries often exploded in the cold leaving the faster KS600 in the snow where the magneto powered R12 would start, a good part of hot motors and cold feet to read is when they are near moscow after Helmuts trusty BMW was turned into its component parts by a russian jabo they are trying to start a zuendapp in the cold, they even light a fire under it but to no avail and end up being towed away from the russians laughing while being towed by a cooks truck! aparently it eventually started after about a kilometer or two.

i would have one though just to keep the krad halle door open while i got "Uschi" out :lol:

lock wire did indeed solve the wheel bolt problem, along with a special tool to get them in and out, i allways did wonder why they were made with the wheel bolts designed to "un do" when you go forward being a left hand thread? i might be wrong there but i do remember something like that?? and it would destroy the drive plate behind it.

all fun aside they are a lovelly looking bike with their own valve tapping sound they do have a terrible turning circle due to those gurder fork things, i have a side car for one in the garage if anyone want to buy it, just the boat but it is original!
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Enigma
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Re: BMW R12 vs Zundapp ks 600

Post by Enigma »

As you have been riding Italian quality products you obviously must be quite able and most likely related to Kenny Rogers somehow. Or maybe you have a R17 engine????

The cold climate in Russia was more suited for the R12. No doubt about that. And it is a very well made machine. The Kardan is a far better construction, but old-fashionedand expensive to manufacture. The fit and finish on the R12 is beautiful. But in the end it belongs in a different age as it is a design from 1929. The KS600 is a very late inter bellum construction. The wheel bolts are weird and has square heads. It is possible to get new ones with unbrako or any other type of heads made if they are a problem. And yes, they have left-hand threads. You will find the same on some other vehicles. I had a Dodge WC-54 once that had wheel bolts with left hand threads on the left side and normal threads on the right side. The reason why it was like that was to prevent them to undo if the bolts became loose. I agree that the fork is not the best part of the construction. And I see the reason why it was changed after the war.

At the end of the day they both are extremely good looking. I have always had a weak spot for plate framed bikes and boxer engines. And the KS600 engine was extremely modern when it came. We just have to make a choice or to get them both, lol, if you cannot decide. I might be interested in the sidecar. I have had some weird desires lately concerning having one. I have an early STEIB munitions trailer for motorcycles somewhere with remnants of Reichswehr green colour on it.
ssparatrooper
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Re: BMW R12 vs Zundapp ks 600

Post by ssparatrooper »

did i speak to you years ago about sum carbs and then a very old gentleman from howe green purchased them from you?
AKA Harvey nightmare

small world perhaps!
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Enigma
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Re: BMW R12 vs Zundapp ks 600

Post by Enigma »

As I have not sold any SUM’s it was not me…..
schwarz engel
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Re: BMW R12 vs Zundapp ks 600

Post by schwarz engel »

bit more for the chit chat, my first zundapp had a mutilated rear drive plate drilled out to 12mm right hand thread soon found they fell out ,!no go go!!.i struggled again after the plate was re drilled 10 mm left hand thread , because all the wheels i had to use had become slightly elongated , movement , so basicially because the krads wernt maintained correctly after the war they got shagged out.ime sure i read once that you could reverse 2 0f the 3 cores on the licht machine so that you could start a dead sammlers zundapp, never tried it so dont know, cant imagine it would be much fun on the steppes of russland.a bit fiddly!! :twisted:
daveydachs
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Re: BMW R12 vs Zundapp ks 600

Post by daveydachs »

I used to have the problem of wheel bolts coming out on the rear wheel of my ks600. I replaced the plate they bolt into with a new one that wasn't worn to buggery and I've never had the problem since, I even doughnutted the bike to hell to test it, those lovely sideways forces used to send the bolts a flying.... no need for lockwire or loctite, happy bunny!
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