Chain Slap - Again!

[thedktor]

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Yes, sorry for raising a frequently discussed subject but its something that annoys me and I want to explore all "cures" thoroughly.

Reading through old posts most are suggesting its vertical slap, whereas other bikes I've had seem to have more a horizontal chain rattle, but to be honest I did not analyze too closely for the brief period of time I had a s/h WR.

So one fix is to put silicon sealant under the top chain slider, which seems fair enough. But is this actually reducing the problem by moving the slider up towards the chain so it cant move so much, rather than providing a softer, quieter surface to bang against? And I guess the question is if its reducing vertical, OR, horizontal chatter.

For those that have doe this, when you are sat on the bike is the chain clear of the slider or does it have to curve over it slightly? I'm thinking increased slider wear.

Also another suggestion was a larger drive sprocket, now I'm happy to go up a tooth anyway but does it actually help?

My issue really goes beyond the noise - it just doesn't sound very good for the bike/chain from a mechanically sympathetic viewpoint! So I would like to understand some more about it.

TD

[chrispy1202]

When i replaced my chain slider there was a piece of thin foam, like the kind you put on a truck box rail before puting a canopy on, which has a adhesive tape back on it. I never put a new strip back on when puting the new chain and slider back on, and notice more chain slapping noise now.

[RickSanson]

I cleaned and masked my swing arm and applied a layer of epoxy. After the epoxy cured I then used RTV to glue the slider to the epoxy layer.

Overkill? Likely but the slap is gone and no chance of swing arm wear...

[Kirkster]

I cleaned and masked my swing arm and applied a layer of epoxy. After the epoxy cured I then used RTV to glue the slider to the epoxy layer.

Overkill? Likely but the slap is gone and no chance of swing arm wear...

How about some pictures of your install...

K

[RickSanson]

There really isn't anything to see...

The slider is slightly raised off the swing arm and it doesn't seem to be wearing down. I saw erosion of the swing arm with only about 5 hours on the bike and decided to use epoxy to prevent further erosion.

I have nearly 40 hours with no sign of the slider degrading...

[w00dsRider]

I went up a tooth and didn't notice any difference in the amount of noise generated by the chain. Then I added a TM design works chain slider and guide. Their slider is taller than stock but made of tougher stuff (read noisier) but the guide did bring the noise factor down a bit. The TM instructions say that you can run the chain tighter than OEM settings but in my experiance it just makes the chain stretch faster. On my 06 the chain will stretch until it is .2" out of spec then it'll stop stretching which makes it quite noisy but sprocket and chain wear nearly stop.

Epoxy sounds like an interesting idea I'll give that a go sometime but I suspect the engine harmonics and drive geometry of our WR's that create this problem are going to be difficult to overcome.

[wrtrailhog]

I tried the foam with adhesive on one side and that lasted quite a few rides, then I experimented with cleaning both the swing arm and the underside of the chain guide with brake cleaner and then hot glued the guide down onto the swing arm and so far so good. Good luck!

[thedktor]

Thanks all, will do some experimenting when I get the bike, and will report back my findings!

TD

[dazzabb]

Are you sure the slap is coming from the chain rubbing the swingarm and not the rear sub-frame?

Have a look at the sub-frame adjacent to the chain and 1-2" above the chain height, it's common to see the chain rubbing there - even when perfectly adjusted as per the Yammy manual.

[thedktor]

OK, so a quick update - my brand new 2006 WR450 for some reason has ZERO chain slap, yes NONE. Interesting to know why. The chain has been set anywhere between 1.5" and 2" slack with no obvious change, and switching between 14 and 15t sprocket has no effect either.

I can only assume its because the guides are not worn.

Anyway, very happy ! ?

TD

[Demo_Slug]

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So one fix is to put silicon sealant under the top chain slider, which seems fair enough. But is this actually reducing the problem by moving the slider up towards the chain so it cant move

my silicon reduces the noise of the impacts. they still slap... but its quieter. the chain slider and the swing arm are 2 flat surfaces that slap together. when they hit each other its kinda like clapping you hands.

BTW, my silicon separated after about 5 rides. it still adhered to the swing arm and to the chain slider. but the two pieces are no longer glued together. and at that point became noisier. but is still quieter then stock.

[KennyMc]

You really notice the slap when riding on the street. I put some 1/4" weather stripping on the swingarm under the chain guide. The slap is gone and it is a easy/cheap replacement if it comes off.