o-ring chain question on 06 YZ450 (and not "which one")

[mtrdrms]

On my CRF450 I needed a small spacer behind my countershaft sprocket or the wider o-ring chain would rub on the case, will I need a similar modification on my YZF? Has anyone had a rubbing issue? I havent gotten the new chain yet so I cant check for myself. Thanks

[SureBlue]

I never had to add a spacer on my '04 with any of the chains, O-ring or X-ring.

I don't know about the '06, but I'd be surprised if it had changed.

[grayracer513]

It's speculation, but if you use a chain like the Regina ORN or ZRH O-ring or Z-ring chains, and the bike isn't too much different than last year's in terms of the available space, you won't have a problem.

Some of the high end chains with monster tensile ratings of 8500 pounds or more do get a little bit fatter, though. RK's are bad about that, and to a lesser extent the DID's. It's a result of making the plates thicker to produce that high a tensile rating instead of using better materials, which would run the cost up. The truth is that tensile strength as a factor in chain longevity on a dirt bike is hugely overblown in importance, and anything over 5000 pounds is pretty much adequate. I'd guess that more than 90% of the "stretch" that happens to the typical chain is wear at the pins, and not actual elongation of the plates.

[mtrdrms]

I agree, and that would explain the chain being able to bend and flex more from side to side when it is getting loose. If the plates simply elongated, that would not be enough to allow the chain to sway and would not cause the chain links to loosen from one another.

[jeffboyd47m]

I have been running a RK X-ring on my 06 YZF since brand new with no problems at all.