Custom Swingarm Bushings (for swinger conversions)

[T8erbug]

I just had a crazy thought that if drilling/reaming out the frame, getting a 16mmx1.0 thread tap off of ebay through the frame would probably make drilling/reaming the 16mm hole a lot easier, as the thread tap would probably be more likely to guide itself really straight through the hole, and ream out half of the metal at the same time. Then running a 16mm reamer through would be pretty easy.

I don't know if this is the best type of reamer to use, but here's the best of the 16mm I could find on ebay:
http://www.ebay.com/itm/180985951610

a 5/8" reamer I linked in that other post I mentioned seemed to be the style that I think would work the best. I am still in favor of having a 1mm thick 225mm wide spacer sleeve made.

So you want to tap the 14mm frame holes out 1mm to make half the hole then ream the threads out? That's not a terrible idea.. In theory it would keep the hole concentric. Hmmmm... Or maybe we're just going nuts to come up with a solution haha.

 

[Smurf]

T8 or Chuck,

If either of you guys can find a machinist to make up some spacers, I'm in. Don't want to ream or drill out the frame bushings unless I absolutely have to.

 

[Guest]

I am not sure what size spacers the 1100 swing arm takes but I just today installed a 96 Bandit 600 rear swing arm on my 78 1000, What I had to do was use the bearing race from the 78 [15mm center] in the bearings on the bandit swing arm as those were 20mm inside. The out side was the same on both bearing races, the length was a little shorter so I had to ad a shim washer to each side. Then I was able to use the original swing arm axle.With no frame drilling . Might be able to do the same with the 1100 swinger

 

[T8erbug]

I am not sure what size spacers the 1100 swing arm takes but I just today installed a 96 Bandit 600 rear swing arm on my 78 1000, What I had to do was use the bearing race from the 78 [15mm center] in the bearings on the bandit swing arm as those were 20mm inside. The out side was the same on both bearing races, the length was a little shorter so I had to ad a shim washer to each side. Then I was able to use the original swing arm axle.With no frame drilling . Might be able to do the same with the 1100 swinger

Unfortunately the GS750 and GS1100 bearing races have different inner AND outer diameters so this wouldn't be possible. I wish I wish I wish. ..

T8 or Chuck,

If either of you guys can find a machinist to make up some spacers, I'm in. Don't want to ream or drill out the frame bushings unless I absolutely have to.

Ben and I are going to see what we can do when he gets back.. I'll use my bike as the experiment ray:.. If it doesn't work then I guess we're all going to have a frame drill out party

 

[daturat100r]

Me not familiar with 1100 swing arm but presumably its setup similar to original s/a with a spacer between inner races but has a 16mm hole where you require it to take the 14mm bolt.A short length of turned bush inserted at each end of spacer will hold the spacer concentric and turned bushes inserted into each of the inner races will reduce the id to required 14mm.
Broaching was wrong term meant burnish and is unneccessary as no relative movement between parts once all clamped up so absolute perfect fit not so important

 

[mlymanz71]

Did you end up drilling out the frame or did you get some bushings mocked up?

 

[Guest]

Here is what my swing arm swap looks like. 16mm new bushings made, bushing hole in the frame, bushing installed, bushing welded in and the swing arm installation.

 

[Guest]

A few more.

 

[T8erbug]

A few more.

I can't view those pics. Any way you can give us a link or post them in another format??

 

[gearhead13]

I just drilled out my frame. The hole is not much bigger, so it guides itself, just let the drill and bit do the job, don't put any side loads on it. The strength of the larger bolt is partly why I went this way as I had already installed an 1100 in it. Why install a stronger swinger and use the weaker bolt and smaller bearings?
When I put in the 1100, I could feel the stock steel swing arm flex when I opened it up.

 

[gearhead13]

I just drilled out my frame. The hole is not much bigger, so it guides itself, just let the drill and bit do the job, don't put any side loads on it. The strength of the larger bolt is partly why I went this way as I had already installed an 1100 in it. Why install a stronger swinger and use the weaker bolt and smaller bearings?
When I put in the 1100, I could feel the stock steel swing arm flex when I opened it up.

 

[Guest]

I can't view those pics. Any way you can give us a link or post them in another format??

Dang I was afraid that would happen. I've been trying to use a different format even though they are in a JPEG format. For some reason anything I try ends up as text. Photobucket can't read them as jpegs either.

 

[Mark Harrop]

I'm going the same route on my 750...(have 1100 alum swingarm) and am waiting to see what the easiest/best solution is...

Like the tap/ream idea....

 

[T8erbug]

I'm going the same route on my 750...(have 1100 alum swingarm) and am waiting to see what the easiest/best solution is...

Like the tap/ream idea....

Tomorrow I will be on it. We will be going the drill and ream route with a drill press. Ben has a drill press at work that's pretty good size and I am going to tear down the bike tonight so I can take the frame in, turn it on it's side, then locate the center in the press. Once we do that I'm going to use wood shims and tie downs to hold it in place so we drill a straight hole that is concentric and will line up with the hole on the other side. I talked to him about machining a bushing that will slide over the 14mm and w/1mm wall thickness take it to 16mm but he said it would just be too tough/likely wouldn't get a good result out of lathing that up. When I mentioned to him my concerns about drilling out the frame he quickly pointed out the drill press and the ease of getting everything to square up. I trust him so we'll just have to see how it turns out. I'll be sure to document it thoroughly so you guys can either A) learn from my mistakes or B) do what I do to get a good result. HOPE FOR B ray:

 

[storm 64]

I agree reamming the frame will work fine. However, if you do not have a Drill press or Boring Mill and your motorcycle is togerther with engine in the frame. The other alturnitive is to make a new inner race and inner spacer.I didn't like the 14mm-16mm spacer idea. What I did was using H-13 tool steel I roughed machined it leaving .050 stock on it. Then I heat treated the race to 38Rc. I then finised machining it to the exact size of the 1100 inner race only with a 14mm hole. I made two sets I have one set left.I could make more if anyone is interested going this route... Norm

 

[postman_pat]

I have a GS750 and am converting it to accept the GS1100 allow swingarm. As many of you know who have been around here for a while or who have already done the swap the choice in conversion basically boils down to boring out your frame to accept the larger diameter GS1100 pivot OR machining your own bushings to make your 750 pivot work with the 1100 swinger. I have opted for the bushing route because I just don't want to take the risk of drilling into the frame and having holes that are not concentric. NOW to my question for all of you GSers. What material should I use for my bushings? What are the stock bushings made out of? Where can I get round stock for a decent deal? Lastly when I get this done there is a good chance I will have spare bushing material machined to the correct dimensions for a GS750-GS1100 swinger swap so if anyone wants to buy the rest of it I'll give it to them at my cost for parts (free labor). PM me. Answers one or all of these questions would be most appreciated! Thanks guys

Probably a bit late to the party but... have you considered aluminum bronze or, even better nickel aluminum bronze as a material. The aluminum bronzes have excellent surface hardness characteristics and are easily machined as well as being suitable for heavy impact loads. Excellent corrosion resistance too. They are used as bearing and bushing materials, and are also used as valve guides. I've machined up aluminum bronze swing-arm bushings with good results.

 

[postman_pat]

Or, Option B.

GS750 uses the 22x29x30 needle roller bearing.

GS1100 uses the 25x33x30 needle roller bearing.

Machine a sleeve with ID 29 and OD 33. Press fit into GSX1100 swing-arm, and then fit the GS750 needle roller bearing into the sleeve.

MUCH easier than drilling out the frame and less risk.

 

[storm 64]

Postman Pat, I like your option "B". With your option "A" are you saying,not using the roller bearing at all? My question is when tighting the pivot bolt wouldn't you be squeezing the swingarm bushings also? I'm starting to think there is no realy right way or wrong way of doing this... Norm

 

[mlymanz71]

Here is my only concern. Machining a new inner race for the 1100 swinger to fit the bearings for a 750 you would be looking at a 1mm wall on the race to make it fit in the swinger and I would be afraid the wall thickness would be too thin to provide adequate strength.

 

[storm 64]

I'm with you on that Mlymanz71. What postman is talking about I making a sleeve that presses into the swingarm. With the I.d.(of the sleeve) the diameter of the 750 roller bearing o.d. Then using the 750 roller bearing and its inner race. If I had a 750 roller bearing at the time I might have gone that route.