Wider swing arm for my tracker?

[bradshaw106]

I am in the process of swapping a set of cb750 wheels on my bike. I have the front all done. But the rear wheel is physically to wide. Does anyone know of a swing arm that is wider at the axle? I am considering machining down the face of my Cush drive hub a 1/2" or so.... But it's still going to be tight..
Any ideas??

 

[hmusket]

I would suggest trying to find a wider swingarm before machining the cush hub, you may run into problems with the sprocket and or chain. What year cb750 wheel do you have? I have a 1975 cb750 swingarm and its about an inch wider at the rear than the xs650. Unfortunately its too wide where it would mount on the bike, and there's no extra metal to cut off at the pivot. Is your goal to have an 18" rear wire wheel, or are you using Comstars?

 

[gggGary]

The big hooha is chain aligned and wheel centered how is that working out? Is that what the cush trim is about>

 

[hmusket]

I don't think he considered the chain alignment, good point, only trying to get the wheel to fit in the swingarm, thats why he wanted to trim the cush.

 

[gggGary]

The EASIEST way to widen a swing arm is to lengthen it. Two swing arms and slugs, cut, weld. As you go longer it get's wider............. you will need a longer axle too.

 

[bradshaw106]

I have definitely considered the chain alignment. That is what I was working on when, I found the wheel don't fit.... The wheels I'm using are a set of hayashi racing wheels from a cb750 there a mag wheel.
I was trying to research possible Honda swing arm swap but could not find a pivot length... Hmusket do you think you could pull some measurements of your arm for me?
I also didn't know if any of the common swing arm swaps were wider? Ie. Fzr600 , radian, ninja 250, gs 500 ????

 

[member3480]

You can put 4" into swing arm and it will widen it a little but if i were you change the arm out completely with a different arm. I have done many on XS 650 and its work but looks good in the end or you can have a wider arm made up any size you want. I do square tube arms for $650.00 and size you want. You can also do like i am doing on this CAFE bike GPZ550 mono. Stock arm is going to look funny if you try to make it wider. What size rim do you have??? Here is a KZ in mock up long arm 200 tire XS mono and i have a GSXR 750 thats going on XS frame

 

[hmusket]

The 1975 cb750 swingarm measures about 9 1/4 at the pivot vs. about 7 3/4 for the 650. Length is about the same I think, I forgot to measure it. However there is no extra to cut off at the pivot. You might want to investigate a Kawasaki 1000 swingarm. You might be able to modify it at the pivot, should have the same axle diameter ..size as the honda and yamaha.

 

[bradshaw106]

The rim is only 2.5". I can get to fit in the swing arm, but just barely.... And I still need to add some sort of caliper mount
On the gpz550 arm how wide is it at the axle? Is it 17mm bearings?

 

[WacoBrian]

i have a 3"added to a stock and it is 9 1/4 insde with out ajusters with axel

 

[bradshaw106]

I took a tape measure and stuck it thru the wheel and eyeballed it to be about 8" wide. So if I figure 1/2" or so to center the wheel then the caliper bracket at another 1/2" it might fit at 9.25

 

[bradshaw106]

I have googling the heck out of different swings arms trying to find dimensions.... My head hurts. Right now I'm leaning towards a gs500 swing arm. Does anyone have experience with them?

 

[bradshaw106]

From what I found the pivot of a gs500 215mm. Not sure on bolt size?
It is also about 2.5" longer. What are the effects of lengthening a swing am?
Also not sure of axle diameter?

 

[hmusket]

I remembered those hayashi wheels and checked out your album. You have a nice build going there, I like the front end. Earlier I mentioned the KZ1000 swing arms. Checked a couple out on eBay, and downloaded pics. They would be wide enough at the rear, and the pivot looks like you can cut it to fit int the 650. Of course, without seeing and measuring its hard to know for sure. I had a KZ550 that I just sold so I could afford to buy another XS, one that I can ride, still a member of the KZrider forum, so I'll post a question to get some info.

 

[bradshaw106]

So I did a little digging on a kz1000 arm.
20.5" long from pivot to end of adjusters
9" pivot width and 9" axle width
16mm pivot bolt.
Hopefully some will respond to your question and confirm this info.

 

[member3480]

GPZ 550 arm is 9" and KZ arm may fit but the outside can only be cut a little because of outer bearings. Stock XS 650 arm 3" over is still 8 1/2 inchs doesn't change with 3"
Six inches it changes to 9 1/4 i have both here.
What you need to know is front measurement on swingarms because a lot of them just like XS have bearings at both ends and really does not leave much to be cut off. What is the size of a XS 750 that may work. GS1100 is a very common one that a lot use but its a square arm not round. How much are you off and with that thin of a rim what tire do you have?

 

[gggGary]

XS750 is shaft
TX750 has basically the same dimensions as XS650.

 

[member3480]

I thought the older XS 750 triple was chain was that shaft?

 

[gggGary]

I thought the older XS 750 triple was chain was that shaft?

All the ones I owned were.

 

[hmusket]

No replies, posted question on KZrider and dotheton. If the KZ pivot is 9", eyeballing the pictures, it looks like you could take of 5/8" on each side without effecting the swingarm. But that just a guess without seeing the internal of the swingarm. I measured the pivot bolt of my 650, it was about 5/8", which is close to 16mm. One of the problems of not living near any boneyards is not being able to see parts. Whatever swingarm you decide would be the best for your needs, you might just have to ante up and buy it and see what happens.