Not for the purists....but....

[Sprunghub]

http://cgi.ebay.de/HONDA-CB-750-Four-F1-26-Jahre-Stillgelegt_W0QQitemZ280360780482QQcmdZViewItemQQptZMotorr%C3%A4der?hash=item4146ce02c2&_trksid=p3286.c0.m14&_trkparms=65%3A10%7C66%3A2%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50

The rear end on this F1 is 'K'd ? to my uneducated eye ?  Is that simply a case of swopping F1 parts for K parts ? or is life more complicated that ?

[Bryanj]

No Tisnt its got a disc

[SteveD CB500K0]

But they've added a chrome guard and rear light unit from a K (?)

[JonnyB]

Front end F1, swingarm and rear wheel F1, Seat and Tank K?, I dunno it's a hybrid alright