Rear Drive for Britta :-(

[trolle]

Hi nhmaf

I have been doing a little research in the OEM catalogue and came up with these results:

r65 LS October 1983 European:  FINAL DRIVE DRUM BRAKE I=31:9=3,44  09/1980  33111241092 $966.97
r65 LS October 1983 USA:         FINAL DRIVE DRUM BRAKE I=32:9=3,56 1 09/1980  33111241093

r65     October 1983 European:  FINAL DRIVE DRUM BRAKE I=31:9=3,44 1 09/1980  33111241092 $966.97  
r65     October 1983 USA:         FINAL DRIVE DRUM BRAKE I=32:9=3,56 1 09/1980  33111241093  

r45     October 1983 European:  FINAL DRIVE DRUM BRAKE I=35:9=3,89 1 09/1980  33111241091

If I understand you right, the r65 will accelerate better but have a lower top speed  in all gears if mounted with a final drive having a higher ratio like the drive of the R45.

With the 31:9 ratio the fifth gear speed at 1000 rpm is 13.75 mph thus giving a (hypothetical) top speed of 110 mph, with the 35:9 ratio of the r45 the fifth gear speed at 1000 rpm will be 12.16 mph with a top speed of 97 mph.

The speed limit on Danish highways is 130 kph ~ 81.5 mph, with the European ratio this corresponds to 5900 rpm, a level at which my engine has no vibrations and sounds real nice. If I mount the r45 drive the rpm will increase to 6700 at the same speed. At this level the engine is still running very nicely but there is more wear and fuel consumption.

On the other hand I will have more power for acceleration when driving in town or on the small roads.

I have just bought an R45 final drive for $110.

Sorry for the thread degradation.

greetings from a stormy, wet and warm (45 F) north

trolle

[suecanada]

Hey John, There's a rear drive on the ibmwr.org marketplace under airhead parts!

BTW I got a email failure notice with what I had as your email address.

[nhmaf]

John,

Did you ever get this sorted out or a replacement final drive ?
I ask, because I recently purchased one on fleabay as a backup for my R65LS and for  use on a future sidecar project. But if you are still stuck without a final drive
for Britta and want one to fix her up again, in the pursuit of good karma I will sell it to you for what I bought it for.  Otherwise I'll keep it in my box of critical airhead parts,
with lumps of kryptonite hahaha  !