Swingarm eaten by chain

Lordy, Lordy, Lordy, what a piece of bad luck! I'll bet you slept well last night after finally sorting that mess out. Those are some good looking repairs you made, I'll bet you never have another minute's trouble. Way to go!

Sarah

WOW! crazy!
Never would have guessed...

Jäger

I'm missing the part about how the rock affected the chain in a way that made the chain rub the slider too much.
Did it tighten the chain, because I thought you checked that initially?
Did it change the angle or alignment of the chain so that it was held too close to the slider? This is what I figure.

Would riding the bike backwards have dislodged the rock? Goldwings have a reverse gear!

Cheers,
Neil

Boondocker wrote:

Jäger

I'm missing the part about how the rock affected the chain in a way that made the chain rub the slider too much.
Did it tighten the chain, because I thought you checked that initially?
Did it change the angle or alignment of the chain so that it was held too close to the slider? This is what I figure.

Would riding the bike backwards have dislodged the rock? Goldwings have a reverse gear!

Chain tightness was correct; geometry was not, so chain was closer to swingarm.

The rock essentially positioned the lower (return) chain an inch closer to the bottom of the swingarm.

I don't think going backwards would have dislodged that rock. Not enough friction between the chain and the rock to grab it and pull it back out of the chain guide.

Jäger,

Glad you figured out the problem!

When I first got my WR I ran the chain according to the specs in the manual, but it was to loose which is was caused the chain to eat through the chain slide and started grinding on the swingarm. Then I found the revised chain tension procedure which tightened up the chain quite a bit. I never replaced the chain slide and havent had a problem ever since.

This problem is definitely caused from the chain being too loose, and in your case the rock probably hid that your chain was getting loose and as the rock wore down the chain started to grind through the slider and your swingarm.

When I first noticed my swingarm being eaten I ran the bike up on the stand with the front sprocket guard off and watched what the chain was doing. The chain being too loose, the friction of the chain itself was causing the chain to following around front sprocket and basically being thrown up from the bottom of the front sprocket towards the swingarm, and it was obvious that when I was sitting on the bike and at speed that the chain would be grinding right on the swingarm.

But again, since I've tightened up the chain I've never had a problem, even with the old partway eaten chain slider. I'll also be more diligent when inspecting the chain guide, as I do not want a Golden BB....

This thread is pretty authoritative. I wore through my slider as well, at which point I removed the sprocket cover and began to study it periodically (riding straight down the road while watching the sprocket is not easy). The mode of wear is a loose chain being flung upward toward the chain slider as it leaves the sprocket. The amount of wear is tied to the size of the sprocket, the degree of looseness in the chain, the typical angle of the swingarm (as dictated by the load, suspension settings, and terrain), and possibly the amount of wear on the front sprocket (hooked teeth will fling the chain more as it leaves the sprocket). There may also be some small contribution from RPM and/or road surface, by way of slapping induced in the chain.

In my case, the slider wore through in ~6000 miles of hard Alaska riding with a 150lb rider and 50lbs of luggage. With that amount of weight, the sag is somewhere around 40% at maximum preload. 13/48 sprocket setup. The chain and front sprocket were completely toast at that time as well.

You can see the amount of wear on the slider and my field fix here. I cut a potion of the top of the slider and used it to shim out the lower from the underside.



With the slider shimmed out it lasted another 500 miles with no additional wear to the swingarm.

Seems like this would be an excellent reference for trailside repairs and such; can we make it a sticky? Thanks

Sarah

With some degree of confidence I can say that the slider will wear with the chain either too tight or too loose
I had put on a new Primary Drive sprocket and chain setup and new slider before departing on the cross country.
I let the chain get too loose in the first 500 miles and got some wear--adjusted the chain and all was great for 4500 more. Checked the wear and chain tension daily. Today toward the end of the day the puppy sounds like a chain saw--more noise than just from the normal end of day dust chain. Stop and find the chain loose--adjust and get to camp. Check tension and the slider--not good news

Luckily I had stuffed the old original slider in for a spare--put it on and that should get me to the Pacific--I hope.
Looks like the Primary Drive chain is good for about 5K miles--my experience says one adjust after install and it will hold until it starts to wear then you get into constant adjustments--looks like I'm there at 5000 miles.

I think that the moral of this story is to change the chain slider often. I just did mine today after around 12,000 miles. Way too late. I'll keep track of the life expectancy of the new one.

Finally got around to checking mine also. Only 4 K on the bike. Chain adjusted properly.
It has definite wear and needs replacing. Does anyone happen to have the part number handy? What it is actually called?
I am going to consider a normal wear problem so I will order an extra slider.
I must not be using the right name for the part on Google.
I am going with a 14/45 to help with the wear problem.

3D7-22151-00-00

14/45 gearing will suck donkeyballs.


yes - it's a absolutely a normal wear part and needs to be replaced once in a while.

I got 10,000 miles out of mine. click me <-- clicky for pictures

If yours needs replacing at 4000 miles most likely have your chain too tight.


watch this video <-- clicky for watching how much your chain moves

Running 13/47 now. Pretty low for street. !4 up front will be fine.
KTW for dirt only in the near future.

I Found something else when doing maintenance.

I don't ride with the front sprocket cover or any sprocket protector.
The shaft of the very bottom screw is all eaten by the chain.

I changed the slider at the begining of the year and it as started to do it again.
I was ridding with the chain too tight. Now I run it with the Yamaha specs and it's doing it again.

Is anybody have the same problem with the screw ? Soon I will not be able to screw anything in there.
Not my pictures but it's the very bottom one. It means that the chain move more than 1 inch to hit it.

I run 13/45 on the street and supermoto track and 13/47 on the dirt.

Marylucky wrote:

I Found something else when doing maintenance.

I don't ride with the front sprocket cover or any sprocket protector.
The shaft of the very bottom screw is all eaten by the chain.

[...]

Are you missing the lower drive chain tensioner?

I will check it tonight... are you talking about the chain roller near the swingarm pivot ?

Marylucky wrote:

I will check it tonight... are you talking about the chain roller near the swingarm pivot ?

Yes, there's two. I was referring to the bottom one.

Easy to spot - right behind foot peg through frame opening.




You're chain is hitting where the red arrow is pointing?

My bike has right around 3k miles and I noticed today leaving work the top of my slider has some pretty deep grooves in it. It looks good up around the front of the swing arm though where the chain normally cuts in on these bikes; weird.

Here's the top view of my old slider and the same surface of the new one.


Grooves in slider is normal. You're supposed to have grooves.

I was just surprised that seemed pretty deep but I guess it is normal. My chain was in need of adjustment too so that probably didn't help either. I keep it adjusted and cleaned/lubed regularly but I have been riding a lot of off-road the last few weeks.

Like brake pads..... a chain slider is a "normal wear item".

Designed to do just that. Wear.

10 inches of suspension travel.

A chain that's too tight will groove out a chain slider more than a chain that's too loose.

I don't know if it truly helps but, I coat the slider with the same teflon spray that I use on the chain.

As far as the top wearing fast, it seems engine braking may play a role.

I engine brake all day and have minimal wear at 7k miles. I keep 14mm of clearance between my swingarm and chain.

What size sprockets are you using? I keep the chain 8mm from the swingarm and I'm using stock sprocket sizes. It was dug in fairly deep considering the bike only had around 100 miles on the clock when I noticed it. Seems the wear basically stopped after I did the first chain adjustment/lube. But, I also started coating the slider at the same time. I've worn out trail wings and replaced them in the mean time and the slider still looks good.

Arkmage wrote:

Try that out. Most of us just push up with our finger... the fancy fish gauge is just a funny joke yamaha plays on us.

14mm means your on the tight side.

I'd rather be loose.
I bet I'm not more than 1/2 an inch from swingarm.

My slider lasted 10,000 miles and I engine brake a shit-ton. Starting to push the limits of breaking that rear loose and begin to feel some "backing in"