What chain is the best for Enduro/Motorcross?

[JAD]

I just bought a new KDX 200 and asked the bike shop to put a good quality
o-ring chain on it because the original standard chain was flogged out after the first 40 miles! They put a RK "U-Ring" chain on it (GB520KZU) and after just 50 miles of enduro riding today it has lost some of the oil from in between the pins and bushes, and is able to be moved from side to side like nobodies business. I don't know what to do. What is the best chain that I could get that will not fail me? And do you think they have sold me the wrong chain?

[Danger]

I like RK X ring chains. Not sure what a U ring chain is. I have had DID X ring chains snap on me.

[JAD]

Is that an RK ... RX or an XW chain that you use. Could you have a look here? Thanks. Are you involved with Proride?

http://www.mickhone.com.au/Acessories/rkchains.htm

[Danger]

I use the XW chain. If using clip joining links, I change the link 3x during the life of the chain. These chains don't stretch much but the link is the weakest point. I replace the chain when I replace both sprockets, altogeather as a set. You get the longest life that way. I also don't lubricate the chain except with WD40.
Yes, I am with ProRide.

[JAD]

Do you abstain from lubing it so as to not attract the mud and dirt?

[JAD]

Also, does the grease leak out of the pins and bushes on the XW chains?

[Danger]

Many people continue to lube the sealed chains. Like I said, I only use WD40. This is because alot of the riding is in sand, and you can chew a chain out in a weekend by lubing it in sand (did that in the early days, ready made grinding paste). The chain has the lube sealed and I have not seen them leak. Infact when I replace the joining link its always still full of grease when taken apart.
The WD40 is just used to desperse water after washing, tho I usually give it a spray between laps also. Just keeps everything running free and not running completely dry.

[crazyxr250rider]

U ring chains (like yours) are not designed to hold lubricant like o/x ring chains the thin rubber rings are merely there to reduce heat and friction that causes wear on standard heavy duty chains use regular chain spray As for the side to side movement The fraise ''basic periodic maintenence'', springs to mind,so try adjusting your chain......

[warewolf]

I have had DID X ring chains snap on me.

Curious, was that a 520VM? On which bike?

I was told that DID 520VM chains were known to fail on the 640s (in Australia), so an RK GXW was suggested.

Someone later said that it was bollocks and profiteering by the seller; they reckoned modern chains are so bloody strong they are almost impossible to repair in the field, that the 640 couldn't produce enough power to break that chain. He's probably right, if tested in laboratory conditions!