Funky chain stuff

[Nomad]

I recently pulled off my wheels to replace the tires and in trying to align the rear axle properly with the right chain tension, had a little hiccup.
I have a 1996 M900, to adjust the chain tension it is a nut on the back of the left side swingarm, there is a little indicator of how far out this nut is so you can match it on the right side of the swingarm and assure that your rear wheel is properly aligned.
The hash marks on the chain side are about dead center with the indicator (axle is in the middle of the adjustable region).  However, on the left side, If I try to loosen the nut to make the proper alignment, the nut has to be pulled so far out that the piece of metal it holds to the swingarm fall loose and dangles.
     Is this an issue of a chain that is too short, or am I overlooking something simple?  I don't understand why the nut would have to be so loose, not even finger tight, to align in the middle of the adjustable region and have the covering of the swingarm fall off, it doesn't make sense.
Thanks for any insight.

[Speeddog]

That 'nut' is actually a bolt.

It cannot push the axle forward, if you loosen that bolt you then need to push the wheel forward.

[seevtsaab]

when you losen the adjusting nut - that side of the axle does not automatically move to the front.

Knock the tire forward or if you care to rap on the adjusting nut to get it flush with he end of the swing arm.

And btw it's recommended to align the rear sprocket to the full run of chain (or other similar methods),
as opposed to referencing the alignment plates on swing arm.

[Nomad]

Thanks guys, my mistake on the "nut/bolt" nomenclature.  I did try loosening the axle and hammering the right side forward with a rubber mallet, but it didn't seem to have much effect.

Could you please elaborate on "And btw it's recommended to align the rear sprocket to the full run of chain (or other similar methods),
as opposed to referencing the alignment plates on swing arm."

I don't understand exactly what you're saying.

[Speeddog]

The alignment plates are usually a very loose fit on the axle and the swingarm, and are not a good measure of actual wheel alignment.

[OldDuckRider]

I've had good luck using this alignment tool for my belt and chain drives:

http://cgi.ebay.com/ebaymotors/Rear-Wheel-Alignment-Tool-Harley-And-Customs-_W0QQcmdZViewItemQQhashZitem53e373f798QQitemZ360298313624QQptZMotorcyclesQ5fPartsQ5fAccessories



Dave

[Nomad]

The alignment plates are usually a very loose fit on the axle and the swingarm, and are not a good measure of actual wheel alignment.

So how would I make sure my wheel is properly aligned, short of getting the tool recommended in the next post?  Ditto for the front wheel I guess, mine appears to be closer to the left fork than the right.

[Speeddog]

I visually align the rear wheel with the front wheel.

[Nomad]

So is it more important to eyeball that the front wheel is centered on the rear wheel, or that the front wheel is centered on the forks and the rear wheel is centered on the swing arm?

[Speeddog]

IMO, it's most important that the front and rear wheels be in line.
Also important that the front wheel is centered in the forks.

With that, and with everything else undamaged and properly assembled, the chain and sprocket alignment will be good.

[WTSDS]

Rear wheel alignment and chain tensioning are best done with  the 'bike on a rear stand.

Ignore all marks, measure from the rear edge of the swing arm to the rearmost of the axle nut flange on both sides. You can use a ruler or a piece of cardboard for this measurement.

Go very easy on those adjusting bolts, or you will strip threads of the gizzers they thread into.

Looking along the top run of the chain will tell you if the rear wheel is properly aligned.

[Düb Lüv]

i measure from the center of the swingarm pivot to the center of the rear axle, and do that for both side. with a visual alignment follow up to check straightness of chain.

[Howie]

i measure from the center of the swingarm pivot to the center of the rear axle, and do that for both side. with a visual alignment follow up to check straightness of chain.

This method works for me too.  Some prefer to line up the sprockets, like Chris Kelley,one of our sponsors.
http://www.ducatitech.com/info/wheelchange.html

Also do not overtighten the chain!  The chain adjusters need to be retightened after the axle nuts or they will come loose and possibly cause damage.  Do you have torque specs?

[64duc]

I visually align the rear wheel with the front wheel.

  +1  I've been doing this for 40+ years. Works for me.

[seevtsaab]

I align the rear sprocket to the front sprocket, assuming that put the rear works in proper alignment.

I lay a straight edge along the rear sprocket and insure it aligns with the inner edge of the outer link plates of the chain, if you can picture that.