Help! Rear wheel spacers/alignment

I would like to ask for your experienced opinions on a custom rear wheel and swingarm set up I am trying to install on my 79 MKII. I have the wheel installed and it looks like it is off to one side by about 1/16" (.063). When I measure from the swingarm to the rim or to the tire, one side is 1/16" longer than the other. How much of a difference does this make? The rear sprocket seems perfectly aligned with the front and the wheel is perfectly straight. To center the wheel, I would have to move it 1/32" (.031), which means having custom spacers machined, etc... Is it worth it???

Thanks!!

Post edited by: 79MKII, at: 2006/07/15 22:10

if the wheels arent inline i think it would track funny,im not sure all far off it needs to be to make a major differance though.

Where is everybody? I haven't had any luck looking on the web either. I assume that things are best when the front and rear wheel centerlines are perfectly aligned, but how much of a difference would 1/32" make? I'm not even sure who could machine the spacers. Any help would be appreciated.
Thanks!

on mine i decided instead of adding shims on top of spacers it would be better to just machine new wheel spacers .just mill the one side down to what it needs to be then make the other just a little bigger to make up the differance you need.

What would be worse out 1/32" on wheel alignment or the same on sprocket alignment? I bet chains and sprockets are not too forgiving of misalignment.

Well, I just wasn't comfortable having the wheel off center, so I went and had the spacers machined today. As close as I can measure using a 6" caliper, the wheel is centered within .001 or .002. I think that's close enough for me! I also checked the sprocket alignment and it seems good too. I'd like to check that a little closer, but can't seem to find a good thread on it. Anyone remember that being covered anywhere before?
Thanks

im sure if you were measure many stock bikes .001-.002 would seem awful close.

wireman wrote:

im sure if you were measure many stock bikes .001-.002 would seem awful close.

That's what I was thinking! I wish I would have thought to measure my old set up before I took it apart. Now that the wheel is centered in the swingarm, I hope the swingarm is centered in the frame! :blink:

I've seen one swingarm manufacturer state on their website that up to 20mm misalignment on wheels was perfectly acceptable! I wouldn't go that far, but I certainly wouldn't worry about a mm or two.

For sprocket alignment I usually use a length of rectangular bar that I am reasonably happy is straight and press it across the face of each sprocket to see if it aligns with the other. I go for less than 1mm misalignment on this one.

To check front to rear wheel alignment I use 2 pieces of 2x2" box section aluminium pressed against the side walls of the rear tyre and extending forward to the front tyre. You can then measure (with a friend) both sides from the box to the front tyre.

I agree with Lorcan. You want the sprockets to line up by using a nice sturdy straight edge. The centerline of the rear wheel will fall where it will, so to speak. I've heard 1/2 inch isn't much to worry about, but I've never personally done that. I've also read where some motorcycles have an offset rear tire from the factory.

When the sprockets are lined up, measure and make custom spacers.

If the rear wheel is offset too much for your taste, then maybe something could be done to the sprocket mounting that will allow the wheel to come back closer to the centerline.

Have you seen the spirit levels with built in laser. I got one cheap from Princess Auto. Place against rear sprocket and shine laser on output shaft.

first get the chain and sprockets dead nuts inline.

if the rear tire is off from the front tire-side to side axis, get a good measurement of that. (center of tire)

the side to side measurement will be how to space front sprocket.

follow suit with the rear wheel make spacers or shims

modified bikes equals modified problems