I recently bought a 1980 Sachs Hercules Prima w/ the 505 1D engine/transmission. It ran when I bought it, but I can't quantify it much more than that. I opened up the transmission to clean it out, and cleaned the piston/bore/head while I was at it. After putting it back together, I noticed that the amount of friction required to pedal it (even without the rear wheel connected and without the piston/flywheel engaged) seemed really excessive. It could have been like this when I bought it.. I don't know. But I've compared the amount of friction to my Puch, and it's like an order of magnitude more than the Puch. I've since reopened the transmission to see of any bearings were misseated, but found nothing that looked amiss. Are there any usual suspects that might be introducing the friction?