Topic: 1978 cb750f swingarm on 1978 cb750k frame

[Dime]

I am wondering if the 1978 cb750f swingarm is a direct bolt up to my 1978 cb750k frame?

The reason I am wondering is because I will be running disc brake on the rear and the f swingarm is already setup for the disc.

Otherwise I have to cut the bracket off of mine and weld it to the top like the disc setup whereas the bracket for the support in on the bottom of mine for the drum setup.

Thanks in advance.

[Alan F.]

Right here in reply#5

http://forums.sohc4.net/index.php?topic=139745.0#lastPost

[Dime]

Right here in reply#5

http://forums.sohc4.net/index.php?topic=139745.0#lastPost

Ok so it seems like the f swingarm and the k swingarm is the same for 78 except the f is setup for disc brake.

Thank you

[Jerry Rxman Griffin aka MuthaF'er]

On the left side, the 77 and 78 F and K both had the double row output shaft bearings which both created the 10mm offset all the way back. Front sprocket cover, swingarm, chain guard, shock mount, rear sprocket flange. That is all equal.

The one piece I do not know is the difference in the lengths if so of the 2 swingarms. 

[Dime]

On the left side, the 77 and 78 F and K both had the double row output shaft bearings which both created the 10mm offset all the way back. Front sprocket cover, swingarm, chain guard, shock mount, rear sprocket flange. That is all equal.

The one piece I do not know is the difference in the lengths if so of the 2 swingarms.

I went ahead and ordered the f swingarm.  Will report back I'd there is a difference in length

[70CB750]

i have done the same combination for Red - and she is a K3 frame with 78f swingarm, disc brake in the rear and 914rr rear master cylinder. 

[Dime]

i have done the same combination for Red - and she is a K3 frame with 78f swingarm, disc brake in the rear and 914rr rear master cylinder.

I think a master cylinder came with the parts stash in the kz1000 ltd stuff. Will have to double check. Definitely have the caliper and floating mount. Didn't have the mount support but that is coming with the 78f swingarm. I think I did pretty well on the 78f swingarm. $92 Canadian to the door.

[newday777]

i have done the same combination for Red - and she is a K3 frame with 78f swingarm, disc brake in the rear and 914rr rear master cylinder.

What is this 914rr rear master cylinder?

[Jerry Rxman Griffin aka MuthaF'er]

On the left side, the 77 and 78 F and K both had the double row output shaft bearings which both created the 10mm offset all the way back. Front sprocket cover, swingarm, chain guard, shock mount, rear sprocket flange. That is all equal.

The one piece I do not know is the difference in the lengths if so of the 2 swingarms.

I went ahead and ordered the f swingarm.  Will report back I'd there is a difference in length

I have both but... didn't measure haha. The 75 F swingarm is in my parts cave and the 77/78 is on my second F where I used a 78 K engine. I had to make the updates due to the 78 engine in the 75 frame.

[Dime]

Just wanted to report back that the 78 cb750k and the 78 cb750f swingarms are both the same length.

The f swingarm is working out perfectly for my application.

[newday777]

Is that a Morris Mag?

[Dime]

Is that a Morris Mag?

I believe they are Kawasaki versions on them. Running a 19" out front. Both came off a 1981 Kawasaki kz1000 ltd. Have the front end from that bike going on as well.

[newday777]

Kawi started using Morris and then made their own with exact copies.

[Alan F.]

Just wanted to report back that the 78 cb750k and the 78 cb750f swingarms are both the same length.

The f swingarm is working out perfectly for my application.

It's always nice when past experiences of forum members all come together to make moments like this possible. In a few years someone will find your threads and learn key pieces of information too.

[Dime]

Kawi started using Morris and then made their own with exact copies.

Cool, I didn't know they were exact copies. Thank you

[Dime]

Just wanted to report back that the 78 cb750k and the 78 cb750f swingarms are both the same length.

The f swingarm is working out perfectly for my application.

It's always nice when past experiences of forum members all come together to make moments like this possible. In a few years someone will find your threads and learn key pieces of information too.

For sure man. I really appreciate any and all help I get from the forum be it answering my questions or doing a forum search. I am learning so much.