EX 500

Joined
May 12, 2007
Messages
150
Location
Rochester Minnesota
Bike
2006 ST1300
STOC #
7969
I thought I would check with the collective wisdom here and see what you'all have to say.
My son just bought a 89 ex 500 with about 25k miles on it. The way he describes the problem is that when he takes both hands off the bars that the front end develops a rather vigorous wobble. According to what he has read on the ex 500 forum, the answer lies in the rear wheel alignment. He says that the rear wheel is aligned to the index marks used when adjusting the chain. I'm inclined to think that either front or rear or both shocks are toast. Any opinions? How difficult is it to rebuild the front/rear shocks and how much is he looking to spend. He lives about 9 hours away so I can't just drop down there to see just exactly what is going on.
 
Joined
May 15, 2009
Messages
219
Age
48
Location
Denver, Colorado
Bike
2008 ST1300
Hello, I had 2 different Kawi EX 500s. Both were the first generation like you've described, an '89 and a '92.

I'd experienced the same issue on my '89. My first attempt was to install the heaviest bar end weights I could find. This did help greatly but the problem still existed. After reading some of the same information your son did, I found the alignment procedure on ex-500.com.

Here's a link to the entire procedure from their senior forum guru FOG. http://www.ex-500.com/37-how-s-fyi/134-wheel-alignment-string-thing.html

Other important issues to note:
1. Ensure the front end is setup correctly. Check for any damage or slightly bent fork tubes. Unless you're the original owner and know the bike's history, they tended to suffer a lot of abuse from new riders learning how to ride.

2. The fork tubes had a tenancy to twist in the triple tree/top and bottom yokes, thereby putting the front end out of alignment as well. To check this, lay a machinists straight edge or piece of plate glass across the the tubes and ensure they're perfectly parallel to one another. Check this in several places, front and back, and ensure the straight edge doesn't rock up and down or have any gap on either side. I believe you can search the ex forum for additional details on this procedure.

3. The index marks on the swing arm are NOT accurate. At least not accurate enough to do a proper alignment to get the chassis from wobbling. You should perform the "String Thing" alignment procedure described in their forum.

Before you jump into rebuilding suspensions, I'd first try to stiffen up the front suspension. Those bikes were badly under-sprung and poorly dampened, even for medium and light weight riders. Go to your local hardware store and purchase some plastic PVC pipe to make yourself some homemade fork spring shims. Start out by cutting a 1 inch long section of the PVC pipe and insert it between the top fork cap and the spring. Go ride it and see what difference it makes. Experiment with different lengths of shims until it is correct for the rider's weight.

Or to help even more, remove the forks from the bike and change out your fork oil while you're installing shims. Going to a heavier weight of fork oil helps. I don't remember the specification but go heavier than what it recommends, e.g. if it calls for 10 weight go for 15, etc.

Hope this helps.
 
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