Let's face it, without your chain, you ain't going anywhere. So why, then, do we ignore our chains for so long? Chains have gotten so good over the past 10 years that it is easy to forget about them. But an ounce of prevention is worth a pound of cure. Which in motorcycling, an ounce of prevention can also be worth a pound of skin.
There are really two main types of chains: O-Ring chains and Non-O-Ring chains. O-Ring chains have, as you would guess, small O-Rings built into them. The O-Rings are used to keep grease and lube inside your chain (between all the moving parts). Non-O-Ring chains do not. Back in the day when O-Ring chains came out, many people believed the O-Rings created high levels of drag. However, that is not the case. A well-maintained O-Ring (X-ring, Y-ring etc) chain provides less drag, requires less maintenance, and lasts a heck of a lot longer.
It is important to remember that the purpose of an O-Ring chain is to keep the lubrication inside. So based on that, there is little you can do to keep your chain in top condition, right? Sorry, but O-Ring chains require attention just like everything else on your bike. A true sign of a squid is a dry, squeaking, rusty chain.
A chain that is ignored will eventually fail, typically by breaking. A broken chain will many times ball-up around the countershaft and front sprocket. When this happens, your chain will rip and tear its way through your soft aluminum motor and will always result in engine damage (either from the chain flailing around or from the motor coming to an immediate stop) Sometimes a chain will get caught in the rear wheel, resulting in an immediate rear wheel skid. Rarely, somebody will get lucky and the chain will fly off the bike without making contact with anything while the rider coasts to a stop (this is rare). In either case, you will be stranded. More than likely, you will have some damage, be it be minor or major.
So now that we've established chain maintenance is probably a good idea, where should we start? Like all things mechanical, let's start with lubrication. You should lube your chain every 500 miles of riding. There are many types of lube available; everything from basic wax, foaming wax, conventional lube to foaming conventional lube. Different lubes will provide different levels of fling and protection. Typically the more fling, the better protection and the less fling the less protection. The hard part is deciding what level of fling/protection you want to deal with. The less fling, the more frequently you'll have to lube.
When your chain is without lube, it will build up a lot of heat and result in the chain stretching. Without lube, your O-Ring will also be exposed to the harmful ozone and ultraviolet rays, causing them to dry out, crack, and even fall off.
It is important (with O-Ring chains) to always lube your chain immediately after riding, while the chain is warm. Remember how we talked about how O-Ring chains keep the lube inside the chain? Well, lubing your chain while still hot will cause the lube to be drawn into the chain as it cools. Also, remember that chain lube's primary job is to lube between the chain and the sprockets.
Also, you need to spray the majority of the lube on the inside of the chain. This helps prevent fling and will force lube into the chain when you are riding. You also need to spray lube directly onto the O-Rings. The best way to do this is along the bottom run of the chain between the front and rear sprockets, spinning the wheel as you go.
Avoid the temptation to prop the bike up on the track stand or center stand, start the bike, put it in first gear while the rear wheel is in the air, and spray as the motor moves the rear wheel. The number of fingers claimed by this exercise is astonishing and a quick search on the Internet will reveal images of people who have lost their fingers doing this (not just dummies, but experienced motorcycle mechanics). It is much better and safer to do it the hard way, with the motor off and the bike in neutral. Click to see what happens when you clean/lube your chain with the engine running »
If you do this regularly, your chain will keep a high level of lubrication but will also draw a lot of dirt and you'll end up with a really dirty-looking chain. Dirt, as I'm sure you can imagine, is very bad for a chain. A good idea is, every 3000 miles or whenever you change your oil, to clean your chain. The easiest way to clean your chain is with a rag, a toothbrush, and kerosene.
Don't use harsh solvents, like gasoline, because they can ruin the O-Rings. Spray or wipe your chain with kerosene. The best part about using kerosene is that it will clean your chain amazingly quick, saving you lots of time. I usually use an old rag and soak it with kerosene and wipe it over the chain until the chain is clean. If the chain is particularly dirty, I'll pour some kerosene into a squirt bottle to apply the cleaner more direclty. Be sure you are in a well ventilated area.
Incidentally, kerosene can be found at any department store, usually in the camping section. Its traditionally used to run camp-stoves or heaters. But be prepared to spend $5.00 for a 10-year supply. After about five minutes you will have an immaculately clean chain and an amazingly filthy rag. Its also a really great idea to remove the countershaft sprocket cover and clean all the excess lube build-up that is around the front sprocket. If you let this stuff build up it can cause problems that you probably do not want to ever deal with.
Be sure you get "kerosene" - not camp fuel or white gas. Camp fuel and white gas comes in the same can as kerosene but it is extremely volatile and will ignite astonishingly easy. Be double and triple sure the can says "Kerosene". Don't trust the store clerk either, if it doesn't say kerosene it is most likely white fuel and that is very dangerous.
Your chain also needs to be adjusted properly. Of course, your owner's manual will have exact requirements for your bike, but the rule of thumb is about 1 to 1.5 inches of slack. But what does that mean and why is that important? Slack is how much the chain will move up and down freely at a point halfway between the two sprockets.
You need slack because as your swingarm moves up to compress for a bump, the chain gets tighter. When a chain is too tight, it will bind on the sprockets, causing quicker wear of both chain and sprockets. A tight chain will also, over time, ruin your countershaft and your countershaft seal (the seal around the shaft that carries the front sprocket) and may even bend the countershaft. Also, a tight chain is more likely to develop tight spots. Tight spots are portions of the chain that stretch at different rates and cause binding between links. So, why not just run the chain really loose? Well, too loose and the chain runs the risk of flying off the sprockets. Bad news! Also, too loose causes a lot of slop in the driveline. Example: twist the throttle, short delay, then lurching as the chain snaps tight, then loose until you are under heavy acceleration. Chain adjustments are very important, even though it may not be something you need to do very often.
If your chain requires adjustment, your owner's manual will have the information you need to tighten/loosen it as there are many different types of adjustment. You will probably need to start by loosening the axle to allow the wheel to move. Then you can turn the adjuster screws, ¼ turn at a time, until you reach the proper adjustment. I like to turn the left one, and then turn the right one the same distance to maintain wheel alignment.
When you achieve proper slack, you need to make sure the wheel alignment is still correct. If the wheel is crooked in the swingarm, your chain and sprockets will wear really rapidly and you can even get into strange handling characteristics. There are two ways to measure alignment. You can grab a flexible tape measure (like what tailors use) and measure from the center of your axle to the center of the swingarm pivot. Or you can string your bike up. Stringing requires you to get a really long piece of string and wrap it around the front tire. Then pull the lengths of string back toward the rear wheel. You can then use your calibrated eyeball to compare the strings with the alignment of the wheels. If your wheel is out of alignment, it will be pretty obvious. I have had a lot of success using the tape measure method. I think it's quicker and more accurate.
After you are confident with your alignment, tighten everything up and check the slack again. Many bikes will tighten chain slack when everything is snugged back down. Check out our Step-by-Step Chain Adjustment How-To Video »
But how do you know when your chain needs to be replaced? Go to your rear sprocket and pull straight back on the chain. If your chain pulls away from the sprockets by much, it is probably stretched out. If the chain does not pull away and stays right on the sprocket, then the chain is not stretched out yet. Also, if your sprockets no longer look like points but a bunch of little hooks you need to replace it all. Another wear indiciation is tight links or kinks in the chain. This is caused by a lack of lube that has caused links stick.
The most common way to know if your chain needs to be replaced comes from measuring your slack. As a chain wears, grooves are cut into the pins which gives the illusion of chain-stretch. No chain wears perfectly even so every chain will develop a variance in the chain slack measurement. If the variance between the tight spots and loose spots of the chain become too great, you'll want to replace the chain. If the chain is not replaced at this point, the variances in slack will put a lot of stress on the sprockets. Replace the chain early and most times you can run two chains to one set of sprockets.
But then there is the master link. Every new bike today comes with a link-less chain. Meaning there is no master link. Every link is riveted. While master link chains are still available, the best idea is to purchase a chain rivet tool (about $30 to $60) so that you can replace your chain with another linkless chain. I would not want to have a master link come apart on a 120hp engine at high speed.
While we are on the subject of chains, a very popular upgrade is to lower the gearing to make the bike quicker off the line at the cost of top speed. The quickest and easiest way to lower gearing is to buy a front sprocket with one less tooth. Simply replacing the front doesn't require a new chain and will cost about $14.00. However, the disadvantages of doing this are pretty significant. First, if you are not replacing your chain at the same time, it will lengthen your wheelbase; that's not such a big deal. But the biggest problem with dropping a tooth in front is you put a lot more torque on your countershaft. Possibly resulting in a ruined seal or worse, a bent countershaft ($$$ expensive $$$). I know of more than one big-twins out there that bent countershafts within 50 miles of dropping to a smaller front sprocket - this is more of an issue with high-torque motors. So the likelihood of this happening depends on how dramatic the change is and the characteristics of the motor, but its good to be aware of this before making any decisions.
We strongly feel that the best way to lower gearing is to add teeth to the rear sprocket. Depending on how dramatic of a change you want, you will probably need a new chain. Usually, you increase four teeth in the rear to equal dropping one tooth in the front (but that varies greatly depending on what your stock gearing is). By changing rear sprockets, you have more control. You can go up any number of teeth to get the result you want. I have typically only gone up one or two teeth in the rear to get the results I wanted. Plus, you are shortening your wheelbase. This is cool if you want to ride a track or a canyon.
Another common upgrade you hear about is a 520 conversion. A 520 is a smaller, lighter chain. The advantage of this upgrade is you will have less rotating mass, less inertia, and therefore an internal dyno like a Dynojet will report a horsepower increase. It's the same reason a lot of people put lighter wheels on their bikes. However, you will probably need to go with aluminum sprockets because 520 steel sprockets are hard to find. Aluminum sprockets mean you will use up chains and sprockets about 30% faster. Plus, because they are a lot lighter, high horsepower engines can snap a cheap or worn 520 chain easily. Another disadvantage is that a 520 chain and sprockets can be as much as 50% more money than a conventional setup. The true advantage of a 520 conversion is the sponsored racer who gets a new chain before every race. Even the most proficient street rider gets very little benefit from this and will not notice any difference.
So, there you have it. The moral of the story is: lube often. A well-lubricated chain is quieter and has a lot less drag allowing the motor to spin the rear wheel without having to force its way past a worn or tight chain. And if you are lubing your chain every 500 miles, you will be very aware of its condition for when it will need an adjustment or a replacement.