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Discussion Starter · #1 ·
Bike is a '05 EX500. I pulled the slack out of my chain for the first time ever and found the axle pulling bolt on the right side to be incredibly sloppy and doesn't really do the job right. I tightened the axle and think it's on straight but I'm having a hard time telling for sure. I've read about a string technique and I tried to replicate but again I don't think I was doing it right. I know there are a couple tools available for checking the how straight the chain is which will inform how straight the rear wheel is or vice versa. Any recommendations on one of these tools are a good demo online for how to do the string test? I'm going to have to take it into the shop if I can't figure this out, and if it's anything like a pedal bike chain I'll be in the shop a little too much for such a simple piece of maintenance.
 

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Providing that the swing arm is concentric (which they usually are) you can take a measurement from each edge of the tire to a fixed point on either side of the swing arm to center the wheel.
I find it amazing, with all the technology poured into today's sport bikes, that you can not rely 100% on the chain adjusters marks for an accurate alignment.
 

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Edit: I guess you have to be a member to directly access that thread at EX-500.com

Here is the first post copy and pasted (courtesy of FOG). There's videos and questions in the rest of the thread.

The String Thing
Motorcycle rear wheel alignment

(Pictures at the bottom)

This applies to chain driven bikes the have two sided swing arms
The most common cause of a lot of the shakes and wobbles that afflict single track vehicles is, they are not on a single track. This set of instruction will fix it.

Mount the bike upright on the center stand or a race stand or lacking those, a pair of cinder blocks and 2X4s.

Wrap a long string around the back tire as high up as it will go without fouling some other part of the bike. A piece of tape will hold it.

Run the string forward on both sides and tie them to a set of moveable objects.

Check to be sure the string is just touching the same part of the tire on all four points and not touching any other part of the motorcycle. Move the front stands so that the string just lightly touches the front edge of the rear tire and is not bent over it.

Now the strings show the path the rear tire is taking on its way to the point where the front tire was. I said that strange sentence to illustrate the point of what were doing here.

Now turn the handle bars to make the front tire parallel to the strings.

Now measure the space from the string to the front wheel rim on both sides. Both measurements should be the same w/in 1/16”

If they are you’re done.

If they are not: adjust the rear wheel chain adjusters to correct the error.

Re- set the strings and measure again. Repeat till OK.

Rocking the Forks

While the bike is still rigged for the horizontal work, do this.
Before we go into the vertical plane it’s important to be sure your front forks are parallel to each other. Forks are often not. This can be easily corrected.
Obtain a flat piece of metal or glass about 3” wide and long enough to span the forks.
Rock this piece across the bare part of the fork tubes just below the bottom triple clamp.
By rock I mean the plate should touch both tubes evenly from top to bottom. If it rocks like a chair with a short leg, that means your tubes are twisted.

To fix this loosen all the pinch bolts on the triple clamps the top center triple clamp nut and the front axel.

Now with you a knee holding the front wheel twist the bars till the plate doesn’t rock.

Then gradually tighten all the bolts while constantly checking the “rocker” till all is tight and the plate doesn’t rock.

Re check the center alignment of the front tire.


Vertical alignment
Not a necessity but if you want to be really really good about this alignment thing.

Your wheels are really big Gyroscopes and as such the angle or Tilt they are on will determine which direction they want to roll in.

Example: Roll a bike (pedal) wheel first straight up and down the with a slight tilt to the right, then left. See what I mean?

Now back to those two Gyros: The back one is much larger, Guess who rules?

While the bike is still rigged for Horizontal alignment.

Rig a plumb line near the rear tire as close to the wheel center as possible.
Measure from that line to the top and bottom of the rear wheel rim, and shim the stands till the rear wheel is square to the earth. That is parallel to the plumb line.

Now rig another plumb line near the front wheel.

Measure from the line to the top and bottom of the front wheel rim. Both of those measurements must be the same.

If so you’re done.

If not:
Depending on how bad, you may be able to adjust this condition.
If worse than ¼” you have a bent frame
If less than ¼” try this:

If the wheel tilts away from the line at the top extent that fork tube in the triple clamps 1/8” conversely shorten the opposite side the same amount.

Re check. Go another 1/8” if necessary.

Re check the horizontal alignment, because you just moved the wheel to the side.

Suplemental instructions: Adjusting the alignment and chain slack

Loosen the big castelated nut, Release the 2 12 mm lock nuts from each other. With the big nut snug but not tight use the 1st 12mm nut against the end cap to adjust the wheel position, mind the chain slack. when a satiafactory alignment is achieved tighten the big nut to 80 lbs. FT. Be sure you have not affecxted the alignment. the back off the 12 mm 1st nut and retighten it to the frame Only finger tight. While holding the 1st nut with a wrench tighten the 2nd nut against it to preserve the settings and secure the end plates. There shoul be no tension on the end plates except the finger tight.


That’s it. No alterations or changes to these instructions will work.
FOG

Thanks to retsmah for these images:

Some pictures of my setup



Not a whole lot of clearance here...


This was about as high as I could get the string without hitting the center stand on the right side.

*MODERATOR NOTE*
Added Video 8/7/10
KS
 

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Discussion Starter · #4 ·
Here:

Login

Edit: I guess you have to be a member to directly access that thread at EX-500.com

Here is the first post copy and pasted (Courtesy of FOG)
I've tried several times to create a login on that site and each time my request is rejected.
 

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I've tried several times to create a login on that site and each time my request is rejected.
That's really weird. I've been a member for almost a year now. Not sure if you can email a MOD or something? Very valuable site.
 

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Discussion Starter · #6 ·
That's really weird. I've been a member for almost a year now. Not sure if you can email a MOD or something? Very valuable site.
I've looked around and couldn't find a contact e-mail. None of the member information seems available to non-members.

Although the wiki is still quite useful.
 

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Providing that the swing arm is concentric (which they usually are) you can take a measurement from each edge of the tire to a fixed point on either side of the swing arm to center the wheel.
I find it amazing, with all the technology poured into today's sport bikes, that you can not rely 100% on the chain adjusters marks for an accurate alignment.
you can on my R6. the swingarm is cast not welded together like a lot of bikes are. it's 100% accurate. I've had it measured with a laser alignment tool.

the easier way to align bikes is by the chain and sprockets with the motion pro chain alignment tool. it's $15.
 
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