As Pinion states, your rear wheel is supposed to be trued with an offset (see the PM, but I think it's a half inch). Yours probably was not. This is a fairly common occurrence, and since your bike came with an 18" rim, the hub was almost certainly laced up to the present rim at a later stage. In the late sixties and seventies everyone was swapping their OEM rim for an aftermarket 16.

Along with a bent swingarm (rare, but it does occur) the other likely culprit are the swing arm bearings. These are rarely serviced by owners, and most old Sportsters need them replaced. Bad swingarm bearings can, indeed, cause your symptoms.

 

MW,

Thanks. I will check the bearings. I appreciate your help.

-Steve

 

I have a 1970 also .. this has happened to me.. Moonwolf is right.. one way to tell if your tire is straight with the swing arm is to look and see if it is centered on the swing arm..this is near the mounting to the frame. Look at the curve in the swing arm and see if it is equal on both sides.. if you change it by too much it won't be able to line up with the front tire.

The only thing I can see to do is the 1/2" offset .. but I want to check and see if this will throw my alignment out.. I use two 8 ft. 2x4 placed along the side the front tire, a framing square helps to get the bike perpendicular. You can do this with one board also. Just check both sides. Look down it to be sure it is straight.

I doubt the swing arm is bent... you would have to be in a pretty bad collision to bend it.. especially side to side.



Jim

 

" The main problem I think is that someone else ( I assume ) other than you laced up the 16 inch rim and hub. In doing so I believe the wheel was laced up with the rim offset to the right side.
Between the two swing arm members is a set amount of space.
Everything that sits on the axle (spacer, hub, brake drum etc) also has an overall dimension out to out. This sits on the axle as I said and the rim has to be centered over this mass.
When you build a wheel up you have to pay close attention to get this correct. I think the builder of your wheel missed this.
The good news is the fact that is fairly easy to correct.
If you are interested in doing this or checking out the offset just let us know...............pg"

**Yeah PG, I am interested in finding out how to do this. Can you send me the link or information?***

Thanks, Steve

 

Steve, there is no link that I am aware of (although I am sure one could be found)
I will include how to build a wheel here for you. If all you want to do is change the offset of the rim relative to the hub, then it only requires you to loosen spokes on the side of the rim that is too close and tighten the spokes (by the same amount) on the other side of the rim as I described. Also, work in half turns of the nipples.
When you have the rim moved over to the new location you will be using 1/4 turns of the nipples to get a final true on the wheel.
Half turns of loosening and then tightening control the wheel movement so that you do not wind up 'building a wheel' instead of just moving the rim over. Any questions just let me know.......pg

 

You are the man!!!

Thanks so much, Steve

 

I have done a little more research and in reading an article in AI, one doing a conversion to disc, one of the factors was the rear wheel and how it fits to the swing arm.. you can't change the way it centers in the swing arm.. that has to stay the same.. as far as I can see this is one of the quirks with Sportster's. What I did do is shim the fender struts, the left one was shimmed off the fender and where it attaches to the frame was left alone.. and on the right side I shimmed it off the frame about a 1/4" and then added some spacers to fit between the fender and the strut.. you have to play with this a little, inside your fender the heads of the bolts must be kept to a minimum or they may cut a nice groove in your tire...

I have doubts about loosening the spokes to make changes.. it is a whole lot easier to shim the fender over a little..

Jim

 

Jim,

Thanks. I was looking at all of those possiblities when I first noticed the wheel not in plane w/ the fender. I did ponder this approach, and it may be that I use a combination of both ideas.

I plan to install the new 16" wheel I purchased this Friday. I have been in communication w/ the person who built the wheel. He says try it like he set it up, and then change it if needed, like the way PG has described.

At least I know my thoughts on how to tackle and rectify the problem is realistic.

Gear heads are mathematicians and problem solvers, they just don't realize it. Although, I am sure some do !!

Thanks for the help all-Steve

 

Not meaning to insult you, but perhaps you have never built a wheel before.
Positioning the rim where you want it to sit relative to the hub is part of building a wheel. The range that exists for you to locate the rim's position goes from the spokes being completely vertical on one side (with the opposite side spokes at an extreme angle) to the reverse of that. Somewhere within this distance lies the point you, the wheel builder, want to place the rim. This is done by adjusting the spokes nipple engagement.

To suggest placing spacers to offset the fender from where it sits in the frame is just incorrect. That is not the way to place the rim in the correct position.
By the way, the track of the rear rim needs to follow the same track of the front wheel. Look into wheel building a little more please......pg

 

I think I would agree totally with you here. "Shimming over the fender" may get you away from rubbing there, but not the right way to do it for someone who takes pride in their bike.