damage swingarm by chain

Hi i have a yz450f 2010  i just noticed the otherday that my swingarm is being eaten by my chain, and it is pretty damage.  now my question is has anyone else had this problem? what did they do to fix it?, can it be welded up?. i dont really see how it happend as my chain is tighten right it has about 55mm play as the manual shows, but its it caused by having a too loose chain or to tight?




Edited by swedetheking86

That blue plastic in the pic is a slider for the chain. You need a new one.

Whoa. That slider probably broke at some point when the chain was really loose. You can use fine grit sandpaper to make it less ugly.

The swing arm is OK, but you need a new slider.  This is a fairly normal wear area, and the slider needs to be inspected from time to time to assure it's OK.

yeah i already got me a new slider, but i was thinking if i can fill the damage area with like gb weld 

yeah i already got me a new slider, but i was thinking if i can fill the damage area with like gb weld 

the jb weld is useless. the new slider should hide the damage

Yeah thats not too bad. This is what happens with loose chain and hooked front sprocket.



just wondering if the damage was that severe could the swing arm be welded? or is it some kind of special aluminum?

Those pics are from my dr650. I found a used one on ebay for cheap. No way that was repairable.

This is pretty common on these bikes. I just had to repair my '14 last week and have done the same to a couple other bikes as well. I missed it on my '08 for so long I had worn all the way in to the bearing race. 


Here are some pics from my latest repair...





I'll need to keep an eye on it from now on, but don't suspect much of a problem. 


Keep proper chain tension!

that looks really good with using JB weld so i think thats what im ganna do to mine :D

You may want to look in to TMDesignworks sliders as well. I just replaced all of mine with their complete kit. I think it runs about $170 or so, but wears much better than stock. Ultimately though, proper chain tension is going to be your best defense against premature or excessive wear.

The slider in the first post is blue plastic.  Maybe not a Designworks, but not stock, either.


Do you guys do a lot of jumping?  The chain is loosest with the swing arm extended, and if you roll the throttle on in the air, the top run of chain is taut while all of the slack is on the bottom, and the chain will curl around the front sprocket and hit at that point.  It can be aggravated by a too loose chain, but it can't be caused by it because the chain will hit like that when set to specs.  It's a normal point of wear that I've seen on bikes, including two of my son's, that I know have never run a loose chain. 


Never run the chain tighter than the minimum called for in the manual.  You'll break stuff.

Yeah, that does appear to be a TMDesignworks slider, though nothing is bullet proof. I have always tried to adjust the chain per the manual and unless I get lazy, am pretty good at keeping it at the proper tension. 


I ride track only and I do my fair share of jumping which would support the extended swing arm/getting on the gas in the air issue when the chain is too loose.


The JB Weld held up nicely on my '08 and I suppose it will with this bike as well. It's not really there for structural purposes as much as it is just to give the chain something to grind on if I get complacent.

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