It's a headache for the casual dirt bike rider to upgrade their chain without going to MMI for a semester. With these men and women in mind I've jotted down a few notes on O-Rings (& X-Rings) versus Non O-Rings. I'll admit, I didn't know what the difference was at one point or why I should even care. As it turns out, there's a relatively simple explanation.(There's a much shorter explanation on our Custom Racing Chain & Sprocket Kits.)
O-Ring / X-Ring
An X-Ring is basically a newer version of the O-Ring, using a slightly different seal to accomplish the lubricating properties of this type chain.
O-Ring and X-Ring chains were developed to maintain lubrication and extend the life of the chain. Chains stretch when they get hot. Knowing this, manufacturers have designed O-Ring and X-Ring chains with lubricant sealed into the chain. This results in cooler chain temperature which allows for longer ride times and virtually no stretching. Less stretching means less wear which means more life for your chain and drive line with less adjustment.
More chain life doesn't come without a cost. O-Ring and X-Ring chains are heavier. They have additional parts that seal lubricant into the chain that Non O-Ring's don't have. More weight means more drag and less speed. More often than not people are willing to make the trade-off, especially on late model 4-strokes where there's plenty of torque to compensate. The weight difference is pretty minute, but then again, some people will buy a honda civic and replace the hood with carbon fiber.
Non O-Ring
Non O-Ring chains have come a long way over the years. They are a lot more durable and stretch-resistant than they used to be, but O and X-Ring chains have evolved to be lighter with less drag as well. If I had to make a gross generalization, Non O-Ring chains
should probably be used by motocross or track riders that need to save every bit of weight and drag that they can. Non O-Ring chains are perfectly suited for shorter ride times. That way it's safe to assume the chain will not be getting hot enough to allow stretching to occur. Even then, manufacturers are claiming that some of their new Non O-Ring chains are pre-stretched or specially treated to avoid stretching from heat. But if I was riding an XR650 in Baja there's no way I would use a Non O-Ring chain.People say that Non O-Rings are easier to clean since they're just links of chain, and there's less metal to get in between and clean gunk out of.
There is a slight reduction in drag with a Non O-Ring chain since it does not have additional parts sealing lubricant into the chain. Fact: Non O-Rings are actually lighter. These differences are so minor that the average rider won't even notice. Maybe it's enough of a difference on a two-stroke 125cc to notice. Maybe? I highly doubt the average 450cc rider would notice. If you're a maintenance freak, you should be okay with a Non O-Ring chain, but just imagine how long an O-Ring or X-Ring would last you!
