R69S Model Years...Early vs. Later

[mike m]

I am looking into buying a fully restored R69S. I thought I read that there were significant updates and upgrades (as there normally is...) over the years during the course of the R69S's model run.

Could someone be so kind to briefly outline the improvements made in model years? Is there any that should be avoided?

TIA!

 

[darrylri]

BMW came out with the R69 in 1956 as a replacement to the R68. This was the start of the Earles fork bikes. In 1958 there were a number of minor changes that were made to update all of the twins; a different spoking pattern for the wheels is the most noticable thing.

In 1961 BMW made some more changes and internally began calling the R50 and R60 the /2s; At this point the R69 became the R69S and lost the manual spark retard lever. It's compression was bumped up and the bike went from 35 to 42HP. During the rest of the 60s, BMW made a number of running changes, but probably the most important are these four:

In 1964 BMW added a vibration damper to the front of the crank on the R69S, necessitating a new front cover that is pushed further out for clearance. The damper was supposed to reduce the number of broken cranks, but it was problematic because the rubber rarely lasted more than a couple thousand miles and made a real mess inside the cover. The repros that BMW is selling today seem to have a good reputation, however.

In 1966, BMW changed the timing chest cover and added a small, separate cover over the oil pump drive. This fascilitates the addition of a tachometer, which otherwise required milling a hole in the front cover to gain access to the cam.

For 1967, BMW changed the heads to accept long reach spark plugs (3/4", rather than the older 1/2" plugs). The heads were cast from a new alloy, and bear the casting LK (lange kerz, or long spark plug) near the spark plug hole.

Late in 1967 BMW brought out the R69US model, with telescopic forks. The frames of these bikes had all of the sidecar mounts elided. The final drive ratio was changed and BMW began recommending a 4.00x18 tire in the rear.

 

[mike m]

Thanks Darryl, great info.

 

[72598]

I believe DarrylRi is wrong on a couple of points, by a factor of one year. (further research reveals conflicting info on these years)

The R69 started in 55 not 56. (the R69 came out mid year in 55 not 56)

The R69S in 60 not 61. (these are dates first made however the imports to US may have been a year later) Vech and Duane both list 61.

http://w6rec.com/duane/bmw/slash.htm

These sites list 60

http://www.ibmwr.org/otech/chassis.html

http://www.motorcycle.com/manufacturer/history-bmw-motorcycle.html

To the OP try the above links, should answear your questions.

 

[darrylri]

The confusion here is that I am talking about model years, not calendar years.

BMW typically made model year changes during August, when all of Germany goes on vacation. So, 1961 model bikes would start being produced in September of 1960.

My own 1961 R60/2 was built in December of 1960.

There is further confusion because it was typical of dealers to register a bike as being of whatever year it was sold. There are many examples of bikes that BMW Mobile Tradition (now Classic) says are from one (model) year but which are registered 1, 2 or even more years later.

Also, some of the changes were "running changes", and appeared beginning with a particular frame number. Those could happen at any time.