Topic: RE: 1996 CB750 Swing arm on my 1976 CB750 Will It Work?

[chewbacca5000]

I was browsing Ebay this morning and came across a swing arm for a 1996 CB750 which uses the same type of shocks as our bikes and would like to know if it would work on my 1976 CB750.

My goal is a cheap performance enhancement to improve stability at speed.  My thought process is honda may have improved this part in 20 years since they first started making these bikes.

It would be great it it worked then there would be no need for me to do the brass busing thing.  A cheap bolt on swing arm with better performance is what I am after.

Thanks!

[chewbacca5000]

I found this thread that talks about the 91 to 03 Nighthawk swing arm http://forums.sohc4.net/index.php?topic=42527.0, and it looks like it will take some effort to make it work.  Is anyone a 91 to 03 Nighthawk swing arm? 

Also, will it provide a handling boost at least on par with the bronze bushings?

[754]

 That one looks like it may fit OVER the frame , not between (just my theory)
Get a measurement, of widest part at pivot and the ID of the hole...ie, bolt  size. Then we can tell you more...

[chewbacca5000]

Ok here is a couple of diagrams from the thread http://forums.sohc4.net/index.php?topic=42527.0, where they did the rear tire swap.  There are no measurements of the pivot.

Let's say the pivot fits would there be a performance improvement over stock? 

[754]

 It looks longer, and back shock mounts are different..if they are wider apart, mounting you shocks (you also have to get) may be trickier .
 I dont have a problem with the length, will increase straight line stability, but change your handling.
 WARNING DISCLAIMER; someone will come along , and tell you tour handling will be detrimentally changed, EVEN if they own bikes with 8 inches longer wheelbase than a CB 750!
 Make your own choices, hundreds of people arehappily  riding on longer swingarms...

[shinyribs]

Message the seller and ask him for some measurements. I just got a ZX arm off ebay and thats what I did. I was looking at two other arms,but they were too wide at the pivot. The ZX is almost a bolt in! except for the monoshock,of course.

As far as improved handling goes,I don't know. If you retain all of the original mounting points (pivot,axle and shocks) then you are not changing any of the suspension geometry,so the only gain you could possibly have would be a stiffer arm. Are you riding hard enough to flex your arm now?

Regardless,if you wanna do it...do it! Mods are always cool!

And I'm with 754 with the longer arm affecting handling in a bad way. When you adjust your chain throughout its life span you can ultimatley shove the rear axle back almost 2'' and nobody ever complains about that. Sometimes it's mind over matter. Unless you would be stretching it a bunch,like 6-8 inches,I wouldn't worry about poor handling issues.

Let us know how it works out!

Just message the seller,it's your best bet.


SANY0056 by Shiny Ribs, on Flickr

[754]

 The ZX arm looks good, I would try bolt on shock mounts , if you dont want to mess with monoshock..
How wide is it? does not look superwide in the pic. 
 I ran a 6 over arm, but probably will change to 4.5 inch..

[chewbacca5000]

Message the seller and ask him for some measurements. I just got a ZX arm off ebay and thats what I did. I was looking at two other arms,but they were too wide at the pivot. The ZX is almost a bolt in! except for the monoshock,of course.

As far as improved handling goes,I don't know. If you retain all of the original mounting points (pivot,axle and shocks) then you are not changing any of the suspension geometry,so the only gain you could possibly have would be a stiffer arm. Are you riding hard enough to flex your arm now?

Regardless,if you wanna do it...do it! Mods are always cool!

And I'm with 754 with the longer arm affecting handling in a bad way. When you adjust your chain throughout its life span you can ultimatley shove the rear axle back almost 2'' and nobody ever complains about that. Sometimes it's mind over matter. Unless you would be stretching it a bunch,like 6-8 inches,I wouldn't worry about poor handling issues.

Let us know how it works out!

Just message the seller,it's your best bet.


SANY0056 by Shiny Ribs, on Flickr

I sent him a message and may pursue if the width of the pivot is about the same.  Just looking for a quick alternative with performance benefits over stock.

[chewbacca5000]

It looks longer, and back shock mounts are different..if they are wider apart, mounting you shocks (you also have to get) may be trickier .
 I dont have a problem with the length, will increase straight line stability, but change your handling.
 WARNING DISCLAIMER; someone will come along , and tell you tour handling will be detrimentally changed, EVEN if they own bikes with 8 inches longer wheelbase than a CB 750!
 Make your own choices, hundreds of people arehappily  riding on longer swingarms...

Thanks 754 I agree a little longer should not make too much of a difference.  Mostly looking to improve straight line handling at speed, but I do like the twist too.  Not sure how it would hurt the twisties?  Also, is my thinking correct that swing arms have improved and that a swing arm from a CB750 might offer handling benefits over a 76?

How hard is it to put the bronze busing in?  I looked at Hondamans book and other write ups and it seem rather challenging.  I do have an extra swing arm to mess with so that helps.

[shinyribs]

I put bronze bushings in my '76. It is not very hard,really. Putting the bushings in a freezer helps a lot. You can tap them in with a hammer and a socket easy enough,but I like to use washers and all thread rod to pull them into place.That way you know they will get started straight and no worries of getting cocked. If you dont have a piece of all thread,you can use the s-arm pivot bolt,you will just have to restack the washers from time to time as you run out of thread.

Muuuuch easier putting the new ones in than getting the old crusty ones out!lol

Most of the places that sell them are getting $45+ for the bronze bushings. You have to keep in mind that place like VintageCB750 charge "Vintage" prices. I got mine off ebay for $25 shipped.

[chewbacca5000]

I put bronze bushings in my '76. It is not very hard,really. Putting the bushings in a freezer helps a lot. You can tap them in with a hammer and a socket easy enough,but I like to use washers and all thread rod to pull them into place.That way you know they will get started straight and no worries of getting cocked. If you dont have a piece of all thread,you can use the s-arm pivot bolt,you will just have to restack the washers from time to time as you run out of thread.

Muuuuch easier putting the new ones in than getting the old crusty ones out!lol

Most of the places that sell them are getting $45+ for the bronze bushings. You have to keep in mind that place like VintageCB750 charge "Vintage" prices. I got mine off ebay for $25 shipped.

Thanks I think I got a piece of all thread laying around and may mess with the extra swing arm in my spare time.  Would like to improve the handling a bit.

[wick]

So. Any info. On the. Size of. The. Nighthawk ' pivot point ?


Thnx