Forum bmwbike.com

Hi Mark,
My 1960 R50 n° 561145 has a 25/8 rate in is final drive gear, and the speedometer is a 0.75 . Is this correct?
The rear wheel is 18 -4.00 (this is not correct, I know) .... and with the 4th gear the bike cannot reach the top speed (130-140 Km/h) and the maximum RPM ; do I need to change the tire?
Thanks.
Michele

Hi Michele
The speedo that you have is correct, and the rear tire should be a 3.50 x 18". The reason why you cannot reach a higher speed with the R50 is most likely due to the larger tire. I would change it if I were you.

Only the R69S changed to a 4.00 x 18" later in the mid 1960's and therefore the speedo was also changed from a 0.75 way speed to 0.77 to correct the reading due to the larger tire.

Hope that answers your questions.

Best regards,

Mark
Mark Huggett GmbH