Topic: CB 750 F and K parts interchangeability

[Martin Thomassen]

Hi

I´m in the very early stages of my CB 750 "cafe" project, which is centered around my 1978 Super Sport F2. Among other things, I would like to fit the side covers and foot rest/rear brake console from the K1-K6 model. Does anybody know if these parts are readily interchangeable with my F2, and possible what parts I will be needing (I guess I need at least the oil tank when converting to the K1-K6 side covers).

Also does any body know for certain what the max. tire width would be on the Comstar wheels (would 140/80-18 or 150/70 fit) in combination with the longer and wider swingarm of the F2 (or so I´ve heard) 

[seanbarney41]

Hi Martin.  I've seen guys make anything work anywhere, but there isn't going to be anything easy about your planned parts swaps.  The mounting tabs of the early k's and your f's side covers are totally different, even if you change the oil tank(I don't think the oil tank will bolt on either).  Early k bikes use a drum rear brake and your f uses a disc, so the footpegs and brake pedals are not gonna play well together either.

[70CB750]

What Sean says, these bikes don't mix well.

I am building - oh so slow - 78F engine to go in K3 frame and I will be using F fork and F wheels; that actually works - see my signature.

[Tugboat]

Note that the swingarm, sprocket carrier & upper rear LH shock mount are 10mm wider on the F2 (and 77/78 K bikes) than on the earlier bikes to make up for the wider output sprocket on the F2 which was used to make up for the use of the 630 chain on the later bikes. If using a later engine on an earlier frame, the quickest/cheapest way to keep your chain straight will be to use the 10mm offset rear sprocket (530!) from CycleX.. you'll need to change the front sprocket to a 530 as well.

http://www.cyclexchange.net/Chain%20Sprocket%20Page.htm