Swing Arm Bushings/Collar Fit
- Thread starter Finnigan
- Start date
barnett468
Coast to Coast
Finnigan said:
your bushings are too small or the end of them got smashed over when they were installed which can easily be fixed by filing the edge a little with a fine round file etc or the steel sleeve is to big . . if the sleeve is orig than the bushing is the problem.
.
barnett468
Coast to Coast
.
Ideally there should be around .0005" - .001" between the sleeve and the bronze bushing.
You should also move it up and down by hand after tightening the swing arm bolt to see if it moves freely.
Put some grease on the bushings and bolt.
.
Ideally there should be around .0005" - .001" between the sleeve and the bronze bushing.
You should also move it up and down by hand after tightening the swing arm bolt to see if it moves freely.
Put some grease on the bushings and bolt.
.
The steel sleeves are the internal bushing. The bronze bushings that are an interference fit in the swingarm are the external counterpart. If you were to assemble the steel sleeves, the center spacer, and end caps (if present - actual parts vary slightly but always achieve the same purpose) into the frame without the swing arm, the whole works will be clamped tightly and rigidly within the frame. None of these parts rotate when the swing arm moves. The arm and bronze bushings spin on the steel sleeves and is located between the two stationary end caps. Tangential play (how far the swingarm can rock side to side) is controlled by the amount of difference between the outside diameter of the steel sleeves and the inside diameter of the bronze bushings, so this difference ideally is as small as possible while still allowing the swingarm to rotate. Axial play (how far the swing arm can slide back and forth between the two sides of the frame) is controlled by shimming the outside ends of the bronze bushings under the end caps. This is usually ignored out of ignorance (most parts books do not even list the shims) but is none the less important.Finnigan said:
As has been promoted, hopefully your installation has deformed the ends of your bushings and this rightly can be addressed with a file. If you drove the bushings in with a hammer - no matter how carefully - this is almost certainly the case. Be advised that the issue hopefully is restricted to the very outside edge of the bore, and so you should keep your file angled so you do not remove material from the bulk of the bore. Having a close fit is why you replace the bushings in the first place, so you don't want to make it sloppy with a file! It is possible that the press fit into the swing arm has made the bore diameter small, but not in my experience. More likely they were the wrong bore diameter to begin with if there was no deformation from installation and the bore is still too small for the steel sleeves. Did you test fit the steel sleeves before installing the bushings? I would not attempt to ream them to the correct size. Push them back out and obtain the correct parts if this turns out to be the case.
Axial shims can be had at any bearing supply. I have never seen them available at a bike dealer. Most all of the ones I have are from existing bikes that have been cannibalized - yes, the factory shims the axial play. It is a trial and error process. I do the assembly "dry" - no grease, just a drop of oil or WD 40. When I have it shimmed to zero play, I take it back apart one last time and re-assemble with grease. The arm should be tight enough then to just fall by its own weight - pretty damn tight, and often a bit tricky to assemble. In 10 miles it will be much looser - just about perfect. You will absolutely notice the difference if you ride hard.
barnett468
Coast to Coast
Finnigan said:
xlnt, but i would still check for binding which will loosen slightly as mentioned, but i would also check for side to side play as mentioned, its obviously not a 200 mph bike and therefore a little side play wont hurt much, but since it is [or was] apart, if it has more than around .005" of side play when tightened, i would fix it but you can probably run .020" and not really tell the diff for your app.