What is this?

[TN Dirtrider]

So I took the back wheel off of the '00 200 I bought recently so that I could change the sprocket and put in new wheel bearings. This "mystery piece" was on the brake side, residing between the wheel spacer and the caliper bracket. I have no idea why it was there, other than to provide some sort of spacer....but I don't know why. Once I was done servicing the wheel I went ahead and put it back in there. Now when I tighten the axle nut up even a little bit you can barely turn the wheel by hand. At first I assumed the rear brake was hanging up, but maybe this piece is causing some issue. I did go ahead and start up the bike on a center stand and it would run in gear, but I have to imagine that whatever is dragging so much is going to rob me of some power.

Suggestions?

[Goofaroo]

Were the wheel bearings shot? Maybe somebody was trying to use it as a shim. Take it out, throw it in the trash, and then see what happens when you reassemble it correctly.

[pumpguy]

Looks to me like what's left of a Devol disk guard. These are held in place in a sandwich arrangement just the way you found this piece. Mine was cracked half way through when I got the bike. I added some extra material on either side to reinforce this area. Devol provides a special spacer with their guard, so you will probably need to replace the spacer on the brake side to get the spacing right.

[TN Dirtrider]

Were the wheel bearings shot? Maybe somebody was trying to use it as a shim. Take it out, throw it in the trash, and then see what happens when you reassemble it correctly.

Wheel bearings were definitely shot.

[TN Dirtrider]

Looks to me like what's left of a Devol disk guard. These are held in place in a sandwich arrangement just the way you found this piece. Mine was cracked half way through when I got the bike. I added some extra material on either side to reinforce this area. Devol provides a special spacer with their guard, so you will probably need to replace the spacer on the brake side to get the spacing right.

The Devol guard isn't stock, so I'm trying to figure out why it would need a spacer. I looked up the parts fiche and didn't see anything that I am missing. If I feel energetic tomorrow I'll pull that piece and out see how it works.

[royadams]

My guess is you forgot to put the tube in between the bearings in the hub. With out it you will never be able to tighten the axle. And they die quickly.

[TN Dirtrider]

My guess is you forgot to put the tube in between the bearings in the hub. With out it you will never be able to tighten the axle. And they die quickly.

Nope...it's in there.

Here is how my "sandwich" looks from left to right:

Axle goes through - chain adjuster, swing arm, wheel spacer, dust seal, bearing, bearing spacer, bearing, cir clip, dust seal, wheel spacer, PICTURED piece, caliber bracket, swing arm, chain adjuster, washer, nut

[6 Riders]

+1 on a Devol disk guard that has broken off. The Devol disk guard & spacer replaced the stock KDX spacer on the right (brake side) of the bike. The guard itself has broken off and all that is left is that piece and the spacer. In order to remove it from the assembly you will need new wheel spacers (or at least the right side one).
I bought an MSR wheel spacer kit to remove my broken disk guard.
Hope this helps, been there done that.

[TN Dirtrider]

Well, I guess it must be my brake sticking then. I'll try to work on that today, though I am no brake expert, to confirm that it is the issue.

Also, when I mentioned above that the bike would run on the stand in gear, that was with the axle nut way looser than you would have it to actually ride. If I tighten the nut up an appropriate amount then the wheel doesn't want to turn at all. That is what was making me think it was something other than the brake, but I don't know what I could have done wrong.

[pumpguy]

In sorting mine out, I had to fuss around with various thickness shims. Even had to put shim washers between the caliper and the caliper holder, due in part to installing new brake pads.

Around the axle, my disk guard ended up being 3/8" thick. So in the end, it ended up being a trial and error process until I could tighten everything up without the wheel binding or dragging.

[TN Dirtrider]

Well, I pulled off the brake caliper and it was still dragging, so it wasn't the brake sticking. I pulled the wheel off and confirmed that (not surprising) the axle spun freely through the wheel and spacers. Put it back together but left off the mystery piece and things are spinning good now. I could see a little gap between the wheel spacer and the swing arm, which closed up as I tightened the nut. It appears to be normal to me now. I have all the pieces installed that show up on the parts fiche, from what I can tell. Still doesn't make sense to me why that one extra spacer would cause such a huge amount of drag. It was only touching the outside of the wheel spacer and the caliper bracket.

[bcdonyo]

Is the spacer on the brake side factory steel or a smaller aluminum one? It looks like a Devol guard to me as well. Are both spacers the same or similar, or is one noticeably a cheaper (Devol) aluminum one?

[TN Dirtrider]

Both spacers were identical, and looked factory to me. The only non-factory looking piece was the broken piece of guard.

[6 Riders]

they probably stuck the guard on w/o a new (properly sized) spacer...which would cause the brake problems that you where having.....and brake that guard right off.