When I align my rear wheel on my new 2012 sportster custom using the 'center of the swing arm shaft to the center of the rear wheel shaft' method, my adjusters are usually a different length by ~1/8 - 3/16". And the 'gap' on each axel slot is also different.

Anyone else notice this on their bikes?

Note: I used all the correct tools and the measurements are dead on and the wheel is centered inside the rear fork.

 

Need to really look and think about what you are aligning. At least on a Softail there is a big tolerance (1/32") for the axle center-line. Most important is the fact that you are aligning the rear sprocket to the motor sprocket. Since there is only two wheels, the handlebars really are what aligns the wheels. With the rear off the ground and bike in neutral, roll the tire as it turns going forward and insure the belt is centered on the sprockets. How does that look? What is your alignment tolerance for axle center-line say in your service manual? On my bike the adjuster are exactly the same. I do throw one side off just about .008 of an inch measured with a dial caliper to better align belt. I installed an extra lock type nut exact same distance from the end of my adjusters to make it easier to measure.

 

Get a 6' long fluorescent light bulb, lay it up against the front/rear tires like a straightedge.

If your axle adjusters aren't the same distance from the swingarm pivot, somethin's not right.

 

Both the swing arm shaft and the rear axel are in perfect alignment according to the manual. The measurement from the center of the swing arm shaft to the center of the rear axel shaft is exactly the same length on both sides.

But the 'adjusters' are different lengths by about 1/8" and the gap in the rear axel slots are not the same on each side ???

 

The important measurement is from center of swingarm bolt to center of wheel axle, they have to be identical. don't worry about how many threads are showing on the adjustment bolts, different lengths showing is common and a non issue. My alignment is set perfect and I have a different amount of threads showing on my alignment bolts, it's always been that way.
I made a tool out of 3/16 steel rod. it is a few feet long with a 90 degree bend at one end, the rod at the bend is a couple of inches and ends in a point. I put the point in the dimple on the swing arm bolt then I have a rubber o ring on the long part of the rod which I line up with the center of the rear axle. I then switch it to the other side of the bike and compare it, it should be the same. I also use a piece of masking tape on the end of the wheel axle bolt to mark the center since it is hollow.

 

Sorry then - sounds like I misunderstood what you were describing. If the distance between the center of the swingarm pivot to the center of the rear axle is the same on both sides, the wheel is properly aligned to the swingarm.

As to the adjusters not sticking out the same length on each end of the swingarm, I'd suggest that you jack up the back wheel, loosen everything up, and ensure that the adjusters are both seated properly in the hollow end of the swingarm. The situation you're describing sounds like one of the adjusters isn't fully seated in the end of the swingarm. If after doing this you still see a delta, then measure the components themselves to see if they actually ARE the same (length of threads on adjuster, slot in swingarm).

I've never seen a swingarm w/that much of a variation from manufacturing vagaries, but, who knows?

As mentioned in my first reply - you've got two alignments to be concerned about: 1) Rear wheel in swingarm 2) rear wheel in line w/front wheel (this is where the 6' fluorescent tubes come in).

I don't know how the rubber-mount XLs adjust the engine/swingarm relative to the centerline of the frame, but, on my FXRT, this adjustment is made using the spherical-end engine mounts. Your FSM should have the procedure, the 28 yr old manual for my bike does.

 

I am using a VT Hollow Axel Plug Alignment plugs in the rear hollow axel and a Motion Pro alignment rod.

Measurement from center of swing arm bolt to center of rear axel shaft is dead on.

Just can't explain the difference in adjuster lengths and the gap difference in the rear axel shaft slots???

All parts appear normal and new from factory.

Is this common?

 

There is no hollow end at the back of the swing arm.

This is a 2012 sportster custom, the ends of the swing arms appear to be a cast iron design with slots for the axel. And these ends are then welded to the swing arms.

Maybe I should measure from the swing arm bolt to the slots to determine if they are the same distance ( length ) and not offset from each other?

 

The whole reason harley does it this way is because they are not worried about the accuracy of the adjuster bolt lengths or the positioning of the axle "slot" in the swingarm. I think your reading too much in to it.

 

I think you may be right, all my other bikes were metric with adjustment marks on the swing arm slots and were accurate.

old ways die hard