Topic: Stiff swingarm

[-JP-]

I rebuild my cb750 k2 swingarm with bronze bushings. Swingarm was also powdercoated. I installed the swingarm back to the bike and now the movement is quite stiff. Can it be the powdercoating making this problem or is there something else wrong? I had to tap the swingarm in to the position where the axle goes thru with a rubber hammer. Is this normal? There are only the bushings in the swingarm and the end caps. So there is nothing extra making this friction. Swingarm moves up and down when I grab it, but I have to use force. I'm thinking it might mess up suspension if it's tight as it is.

-JP-

[Medyo Bastos]

how thick was the pc on the ends before installing bronze bushings?  it doesn't take a lot to make things stiffen up...

[pjlogue]

The swing arm should drop under its own weight (no tire attached) when the end nuts are torqued down.  The powder coating might cause some extra friction if it is built up on the edge of the swing arm bore.  Since it was powder coated are you sure you really cleaned the bore of the swing  arm from any sandblasting residue?

When I coated my 750 swing arm I had taped over the end of the bore so no powder coating got on the edge.  If buildup on the end of the bore is your problem it should disappear if the end nuts are loosened.  You can carefully remove the coating with a dremmel or a razor.

-P.

[-JP-]

how thick was the pc on the ends before installing bronze bushings?  it doesn't take a lot to make things stiffen up...

I'm not really sure about the thickness. Old oem paint was blasted off and then pc.

[-JP-]

The swing arm should drop under its own weight (no tire attached) when the end nuts are torqued down.  The powder coating might cause some extra friction if it is built up on the edge of the swing arm bore.  Since it was powder coated are you sure you really cleaned the bore of the swing  arm from any sandblasting residue?

When I coated my 750 swing arm I had taped over the end of the bore so no powder coating got on the edge.  If buildup on the end of the bore is your problem it should disappear if the end nuts are loosened.  You can carefully remove the coating with a dremmel or a razor.

-P.

Ok. Thanks. It definately won't drop under it's own weight.

[754]

How much pressure ? If you got a fishing scale measure it..
Is suspect it will run in in a few hundred miles.
 FWIW Harleys use.  Around 8-12 lbs at the axle IIRC.... Different bearings.. But I am addressing will abit of preload hurt things..

[riffman12]

I had a similar issue with my PC'd swingarm and bronze bushings. In the end I figured out that the tiny layer of powder coat on the edge of the swingarm was enough to make the bushings stick out slightly further than the collar. It should be the other way around. We're talking fractions of a millimeter here.

I took the end of my bronze busings and lightly filed them and rubbed them against some sand paper. Eventually I got it to where the collar stuck ever so slightly past the busings and the swingarm moved freely.

Hope that helps

[-JP-]

How much pressure ? If you got a fishing scale measure it..
Is suspect it will run in in a few hundred miles.
 FWIW Harleys use.  Around 8-12 lbs at the axle IIRC.... Different bearings.. But I am addressing will abit of preload hurt things..

Well I was thinking the same thing that maybe a couple of miles will loosen it. I don't have a scale to measure it. Everything is in place like it should. Just can't figure out whats wrong with it. I double checked the bushings that they were the right ones. Maybe I have to take it off and have another look.

[-JP-]

I had a similar issue with my PC'd swingarm and bronze bushings. In the end I figured out that the tiny layer of powder coat on the edge of the swingarm was enough to make the bushings stick out slightly further than the collar. It should be the other way around. We're talking fractions of a millimeter here.

I took the end of my bronze busings and lightly filed them and rubbed them against some sand paper. Eventually I got it to where the collar stuck ever so slightly past the busings and the swingarm moved freely.

Hope that helps

I will look in to that. Thanks a lot.

[Rookster]

When the new bushings are driven in they can deform.  Was it difficult to get the swingarm collar back in?  Many times the bushings need to be honed or reamed back to size in order for the collar to fit correctly.  Unless it is really tight it should wear in over time.

Scott

[-JP-]

When the new bushings are driven in they can deform.  Was it difficult to get the swingarm collar back in?  Many times the bushings need to be honed or reamed back to size in order for the collar to fit correctly.  Unless it is really tight it should wear in over time.

Scott

Swing arm collar went in easily. If you mean that pipe with the grease grooves. There were no problems. Only problem is that the swing arm is too wide to fit. I had to use hammer to get the holes line up. I also had to tap the axle in. It was greased but it was impossiple to push it thru just by hand.

[disco]

Like Riffman says......unless the swingarm collar protrudes ever so slightly beyond the swingarm itself, then it will bind up. I think the bronze bushes are slightly 'dimensionally off' as mine did the same & I made sure there was no PC in that area. Lightly file as previously mentioned so that collar is slightly proud.