Author Topic: Swing arm CB750  (Read 6505 times)

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Offline lucky

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Swing arm CB750
« on: October 20, 2011, 06:30:28 PM »
Is the Honda 1980 DOHC swing arm longer than the CB750 swing arm?

They are interchangeable with the CB750 SOHC frame.

Offline Danno

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Re: Swing arm CB750
« Reply #1 on: October 20, 2011, 07:30:39 PM »
I believe so if i remember right they are
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Offline lucky

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Re: Swing arm CB750
« Reply #2 on: October 20, 2011, 08:45:45 PM »
I believe so if i remember right they are

Thanks for that quick response Danno.

Now I wish we knew the length of both the 77-78 CB750K and the 1980 DOHC model. Anyone??

Offline Dyrden

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Re: Swing arm CB750
« Reply #3 on: October 20, 2011, 09:47:51 PM »
Its on this site in another thread.  Look up swing arm swap and its in the middle of the pages.

Offline I Zombie

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Re: Swing arm CB750
« Reply #4 on: October 21, 2011, 08:00:59 AM »
The DOHC arm is about 1.5 inches longer. The pivot tube needs to be trimmed about 3/8-1/2 inch on the right side in order to fit the 750 frame.
Here this link helped me alot.
http://forums.sohc4.net/index.php?topic=46599.0;all
« Last Edit: October 21, 2011, 08:08:03 AM by I Zombie »
78 CB750K

Offline 754

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Re: Swing arm CB750
« Reply #5 on: October 21, 2011, 08:37:15 AM »
The 77/78 are about 7/8 or an inch longer.. and a bit wider. You will probably need the axle adjusters, and back block pieces..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

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73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline 754

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Re: Swing arm CB750
« Reply #6 on: October 21, 2011, 08:39:43 AM »
Get your flack jacket on, even suggesting a minor increase of wheelbase on here is usually followed by a few posts telling you your bike will never handle properly again.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline I Zombie

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Re: Swing arm CB750
« Reply #7 on: October 21, 2011, 08:46:15 AM »
The swap went pretty well on my 78K, rear axle & adjusters fit fine, only real fun part was opening the pivot holes on the frame for the bigger bolt to pass through.
I guess the link I posted is junk seeing all the pic's are gone, with the size differences & length references, sorry.
« Last Edit: October 21, 2011, 08:47:53 AM by I Zombie »
78 CB750K

Offline lucky

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Re: Swing arm CB750
« Reply #8 on: October 21, 2011, 11:40:37 AM »
Get your flack jacket on, even suggesting a minor increase of wheelbase on here is usually followed by a few posts telling you your bike will never handle properly again.

Thanks for the heads up 754.

Offline lucky

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Re: Swing arm CB750
« Reply #9 on: October 21, 2011, 11:42:02 AM »
Get your flack jacket on, even suggesting a minor increase of wheelbase on here is usually followed by a few posts telling you your bike will never handle properly again.

Thanks for the heads up 754.

Also it makes no sense because Honda is the one that increased the swing arm on the 1980 bikes.

Offline Duke McDukiedook

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Re: Swing arm CB750
« Reply #10 on: October 21, 2011, 12:34:08 PM »
What makes no sense to you? The fact that the handling of your bike will change by lengthening the wheelbase? Honda changed the length of the swingarm on the 80 CB750, so what?

I could fit one of those outrageously long swingarms that people slap on hayabusas on my 750, doesn't mean that I really should. What is wrong with the SOHC cb750 swingarm that you can't use it? They have them all over feebay and odds are they have a few in your local moto boneyard for probably a few sheckles.
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Offline Retro Rocket

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Re: Swing arm CB750
« Reply #11 on: October 21, 2011, 03:28:45 PM »
Get your flack jacket on, even suggesting a minor increase of wheelbase on here is usually followed by a few posts telling you your bike will never handle properly again.

Thanks for the heads up 754.


Frank, no need to dramatize mate, we talk of monoshock conversions where the wheelbase is 6-8 inches longer, that does screw up the handling, and when we talk handling mate we actually include CORNERS..... ;D ;)

Quote
Also it makes no sense because Honda is the one that increased the swing arm on the 1980 bikes.

It makes sense if you know what you are talking about, they  changed just about everything else including rake and trail and swingarm pivot to steering neck dimensions as well, which is vitally important in making a bike handle well {it was also 1979}.  Sticking on a longer arm lowers the bike at the rear changing cornering clearance, rake and trail, so it DOES make a difference to the way the bike will handle.... 
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline 754

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Re: Swing arm CB750
« Reply #12 on: October 21, 2011, 07:11:37 PM »
 Maybe they are changing it for TRACTION or LOOKS, some of us care about that...
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Retro Rocket

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Re: Swing arm CB750
« Reply #13 on: October 21, 2011, 11:21:55 PM »
Maybe they are changing it for TRACTION or LOOKS, some of us care about that...

He was talking about handling and so were you, that is what i replied too. Seems your version of handling is going straight down the highway.   Generally,  handling also includes corners.... :P
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.