Chains 101

[frostbite]

Since I'm in need of a new chain (stocker is toast) I began doing some research and learned a few things. Hopefully what I've outlined below will be helpful. I tried to be as factual as possible but if any errors or omissions are present please post them in this thread.

There are currently 3 basic types of chains:

1) Standard

This is your run of the mill chain. Disregard such monikers as 'Heavy Duty' and instead determine chain grade based on tensile strength and wear index. I'll explain these later.

2) O-Ring

This chain has round rubber (neoprene, plastic, etc...) seals lodged between the inner and out links. The purpose of these rings is to contain a factory sealed lubricant against the rollers.



3) X-Ring

This chain is similar to the O-Ring except the rubber seal has an inner and outer edge. This double edge provides extra protection in the event of seal tearing. If the outer edge tears the inner remains to keep the llubricant intact. The 'X' denotes the shape of a cross-section of the ring.





Now that we're familiar with the varieties of chains on the market we can decide which is best right? Not quite. There are 2 ratings applied to chains - Tensile Strength and Chain Wear Index.

Tensile Strength

Tensile strength (rated in lbs or KN) determines the breaking point of the chain. The higher the tensile strength the stronger the chain. If the tensile strength is greater than the max force applied to the chain there is no benefit gained from using a higher tensile strength chain. For example, say you're running a 200cc thumper. A 9000lb chain is major overkill. Typically, the higher the tensile strength, the more expensive the chain.

Chain Wear Index

I had a hard time finding info on this one but to the best of my reckoning each chain is assigned a wear rating. The higher the wear rating the longer the chain will last. For example, a chain with a wear rating of 300 should outlast a chain with a rating of 100. If anyone knows what the actual values represent or how they're calculated please let me know.


Chain Maintenance

Regardless of which chain type you choose regular maintenance is critical if you want to get the longest life possible out of your chain. There is somewhat of a misconception that O/X-Ring chains require no maintenance. For example:




This is false, while any spray lube will probably not penetrate intact O/X rings it will serve to prevent rust and lubricate other parts of the chain. It would be more accurate to say they require a bit less maintenance than a conventional chain

Probably the best thing you can do is regularly clean your chain before lubrication. This allows for better penetration of lube, easier chain movement, and cooler chain operation. Heat is a major factor in chain wear. For years I've used WD-40 (What's in a name: WD-40 - Water Displacement , Experiment #40). This may not be good idea on O/X-Ring chains since there is some evidence to suggest that it penetrates the ring seal and dissolves the lubricant. Also, be careful not to damage the rings when cleaning an O/X-Ring chain. Avoid wire brushes at all costs.

When applying lubricant there are few things to consider:

- Apply to the upper surface of the chain, directly on the junction between the inner and outer links. By applying to the upper surface of the chain it allows gravity to work in your favour and allow for better penetration. Too many times I've given a shot of lube to the back of the rear sprocket while giving the tire a spin.

- Let it sit before riding. Another mistake I made was lubing the chain just before a ride, subsequently spinning most of the lube onto the rear tire. The spray lubes use a 'carrier'; it thins the lube and allows for better penetration. This carrier will evaporate after a short period (20 minutes?) leaving the now heavier, and stickier, lube on the chain. Take off too soon and bye-bye chain lube, and later bye-bye chain.

As far as chain lube selection...well that is for another post. Its right up there with 'which motor oil is best', 'engine break-in methods', or 'Ford vs. Chevy'.

Also, don't forget the importance of proper chain tension/slack adjustment. A chain that is too tight will wear faster than a chain running too loose. This is especially important on bikes with longer suspension travel (e.g. Street/Trail). I know its hard, instinct tells you to cinch that chain up tight! Resist! Not only will your chain last longer you'll probably get better ride quality out of the deal.

Summary

What does all this mean? Should I run O-Ring, X-Ring, or Standard? What tensile strength or wear rating should I aim for? Often I've heard, "Just get a good O-Ring.....".

The answer......wait for it.....it depends.

If you are a Nazi when it comes to chain maintenance you'll probably get really good life from a standard chain, provided it was a 'good' wear index and the tensile strength is appropriate for your engine. You'll probably save more than a few bucks too. If your're not so anal with regards to maintenance perhaps an O/X Ring is better for you.

Budget is defintely a factor. In my recent search for a chain prices ranged from $17 for an el cheapo to $70 for a 'Heavy Duty X-Ring'.

Be informed. If you hit the local bike dealer and they try to sell you the 'premium chain' get the tensile strength and wear index numbers and compare to their other offerings. You may find the price differential is much greater then the actual quality differences. If a given chain is of the same type (e.g. O-Ring) and has the same tensile strength and wear index ratings does it really matter if its an RK, DID, or Honda chain?