A couple of years ago Semprini posted the below:-
Wonder if anyone could throw some light on my speedo problem. The unit on the bike (A65S from Germany) is a km/hr one which flutters badly, so bought a repro grey-faced one from a classic bike company . Checking with my phone GPs
, it seriously under-read the speed. He sent a second one out, this one reads 24mph at an actual 30mph. My original is SSM 5000/04A 1000. The gearbox is stamped 2:1, the rear tyre is a newish 4.00 x 18. A new cable has been fitted. A sticker on the base of the repro says M=2.0
I now have the exact same problem on a B441, does anyone know of the resolution? I know I should have a 1:25 drive with a 1000 speedo OR a 2:1 with a 1600.