Author Topic: 1976f swing arm swap to a 1972 cb750 frame?  (Read 1378 times)

0 Members and 1 Guest are viewing this topic.

Offline la ca fe

  • Enthusiast
  • **
  • Posts: 139
1976f swing arm swap to a 1972 cb750 frame?
« on: September 24, 2015, 09:24:37 AM »
I have a rear end to a '76f frame (wheel, swing arm, brakes...) and am wondering if it will be a easy bolt on to a '72 frame?
Will the sprockets line up? Or is there any fabrication needed?

Thanks.
1973 cb750
1977 cb750k
1975 cb750 f

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 19,905
  • Saver of unloved motorcycles.
Re: 1976f swing arm swap to a 1972 cb750 frame?
« Reply #1 on: September 24, 2015, 09:31:58 AM »
 The drum to disc brake conversion is the obvious problem. At minimum the brake stay will need to be modified to work on a drum brake or if you go with disc brakes the master cylinder needs mounted.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline 70CB750

  • Labor omnia vincit improbus.
  • Really Old Timer ...
  • *******
  • Posts: 14,802
  • Northern Virginia
Re: 1976f swing arm swap to a 1972 cb750 frame?
« Reply #2 on: September 24, 2015, 09:43:29 AM »
I used 78F engine, wheels, forks and swingarm in 73 frame.  See my built thread:

http://forums.sohc4.net/index.php/topic,115305.msg1299318.html#msg1299318

rear brake uses CBR900 Master cylinder and I also had to replace the left rear top shock mount.
Prokop
_______________
Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline la ca fe

  • Enthusiast
  • **
  • Posts: 139
Re: 1976f swing arm swap to a 1972 cb750 frame?
« Reply #3 on: September 24, 2015, 09:51:58 AM »
Will the sprockets line up if I use the rear disk conversion?

I am hoping to do a direct bolt on, '76f rear swing arm, disc brake hub and 17" Hondamatic aluminum spoke rim. I will fabricate rear sets.
1973 cb750
1977 cb750k
1975 cb750 f

Offline 70CB750

  • Labor omnia vincit improbus.
  • Really Old Timer ...
  • *******
  • Posts: 14,802
  • Northern Virginia
Re: 1976f swing arm swap to a 1972 cb750 frame?
« Reply #4 on: September 24, 2015, 10:08:16 AM »
They did for me, since I used 78 engine and wheels.


Here is some info on sprocket carriers, all the way down on that page:

http://www.cyclexchange.net/Chain%20Sprocket%20Page.htm
Prokop
_______________
Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,912
  • Bought her new 4/75
Re: 1976f swing arm swap to a 1972 cb750 frame?
« Reply #5 on: September 24, 2015, 12:50:26 PM »
Will the sprockets line up if I use the rear disk conversion?

I am hoping to do a direct bolt on, '76f rear swing arm, disc brake hub and 17" Hondamatic aluminum spoke rim. I will fabricate rear sets.

Should be fine as long as you are not using a 77 or 78 engine. The output shaft of the 76 F is the same length as yours, just doesn't have the chain oiler that you do.

I'm doing a 78 engine in my 75 F frame. Different output shaft so I gotta change everything behind it including swing arm and rear sprocket carrier and I'm having an adapter custom made for the left upper shock mount.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline la ca fe

  • Enthusiast
  • **
  • Posts: 139
Re: 1976f swing arm swap to a 1972 cb750 frame?
« Reply #6 on: September 24, 2015, 10:31:36 PM »
Thank you very much!
1973 cb750
1977 cb750k
1975 cb750 f