Vintage BMW Motorcycle Owners

I am looking for some suggestion's for R69s tires, Max's in NH have Metezer Block C. I could run 3:50 x 18 front and rear, what about a 4:00 on the rear and why would I want to.

Paul

I do Metzler C block on all my /2's. Regardless of what you get you will want to stick to 350 front & rear on an Earles Fork bike. The 400 is to tall and wide and has a tendency to cause the center stand to be a little shaky, you will also notice some handling issues with the bigger profile tire in the rear.

My US bikes have 350 front and 400 rear, Continentals on one and Metzler C blocks for the other.

Checkout Pirelli or Avon modern,round profile tires. They transform the riding experience. They don't tramline as much, and cornering is much more enjoyable. I tried the Metzeler and I am glad I went tp a modern tire. If you are a rider,and plan to do any freeway the modern tire is far superior.

I run a 4.00 on the rear of my late R69S. BMW introduced a new rear end drive 27/8 so they recommended that the taller rear tire be used. I've not noticed any issues with handling or use of center stand with the taller tire.

http://www.beemergarage.com/documents/267.pdf

I run the Metzler 350 C Block on my /2 and Im very happy with them. No issues. I only wish I got more milage out of them.

Heidenau!

Same size front and rear is a must. Heidenau K34 or K36.

jwonder wrote: ↑

Tue Aug 16, 2022 4:54 pm

Same size front and rear is a must.

James -

I never understood that. How is a "must"? BMW indicated that with a change in the final drive, a larger tire should be fitted. If you don't use the "right" tire, then I guess the speedometer will have some error in it.

Just curious as to how important this really is...

Kurt, Great question and one I ask myself as well.

All I know is that when I was new at vintage BMW's, I put a mixed set on my 1966 R 50/2 (3.5 front and 4.0 rear) and the motorcycle was horrible handling. I replaced the rear and it was day and night. I am not alone in having this happen either. As for the larger rear in the later years, no geometry changes were made to the motorcycle so who knows. Not really sure on that.

Maybe Vech or someone else can help fill us in.

Kurt, I just read the service bulletins and it is very questionable on why they made the change. One bulletin says they are for sidecar and the other says it's for "higher speed". Read the bulletins below.

See:

https://vintagebmw.org/library_data/249.pdf
https://vintagebmw.org/library_data/261.pdf
https://vintagebmw.org/library_data/243.pdf
https://vintagebmw.org/library_data/267.pdf