The Bicycle is one of the most efficient vehicles ever built. It will take an individual farther for a given amount of energy than any other form of transportation. One reason for this is the chain drive.
Basically unchanged for one hundred years, the chain drive allows only two percent of energy to be lost between the chainrings and the cassette. By comparison, even the most fuel efficient car loses about 80 percent of the engine's energy before it moves the car. Complementing its ability to conserve power, a bicycle is one of the most frugal forms of transportation, requiring less than two cents per mile to operate.
http://www.bikeleague.org/resources/better/maintenance.php
Chain Replacement
The modern bicycle chain has a half inch pitch, meaning it is one half inch, pin to pin. One link consists of two inner plates, two outer plates, two pins and two rollers. While the pins fit tightly into the outer plates, both the inner plates and the rollers pivot freely on the pins.
As a chain wears out, so do the chainrings on your cranks and the cogs on your rear wheel. How do you prevent such damage? Well, there are a few theories about how to keep the drivetrain of your bike in good working order without spending too much money.
One is the "Replace Your Chain Before It Wears Out" theory. Keeping constant vigil over your chain by checking it monthly and replacing it as soon as it wears out will make your other parts last much longer. If you ride regularly, you may require as many as three to four chains each year. Estimated cost: $30 to $150, depending on quality of chain and labor costs.
The other is the "Lazy Person's Wait Until It's Finished" theory. This follows the idea that your bike will tell you when it's ready to have its chain replaced. As chains stretch, cog sets wear out and so do small chainrings. When you pedal under load, (uphill, for example) and your chain 'skips,' you are seeing the end of the road for most of your drivetrain. At this point, you need a new chain, cassette and quite possibly a new small chainring. Under normal road conditions, you might realistically expect to get two years out of these parts.
Chain Care
In order to get the maximum life from your chain, you should consider three things:
- Quality of the Chain: The differences between less expensive and more expensive chains are the shape of the plates, quality of materials and the riveting of the pins. Chain side plates are designed to help the chain shift better, so better quality equals smoother shifts. Higher quality materials are used on more expensive chains increase chain life. In addition, pins are 'mushroomed' in the higher quality chains after they are pushed into the plates at the factory. This process increases the tolerances of the chain plates and makes for a stronger, longer lasting chain.
- Maintaining Your Chain: Regular maintenance of your chain need not be a lengthy or messy process. Simply put: If you can see dirt on the outside of your chain you should to wipe it down with a clean rag. If your chain squeaks or is excessively noisy, it needs lubrication. Remember-- if you can see the lube on the chain, there is too much. Wipe it down with a clean rag. Only the inside of the chain needs to be lubricated. There are many types of lubricants out there for bike chains-- dry, wet, self-cleaning, etc. Find one that works for you and learn how to use it properly. Telling someone what type of lube to use is like telling them what kind of underwear to buy. As a general rule, if you ride where it's wet, use a wet lube. If you ride where it's dry, use a dry lube. You should avoid spray applicators as they tend to be very messy. To apply lube to your chain, pedal the cranks backwards about four times and drip the lube onto the chain. It helps to rest your hand with the lube on your chainstay and contact the lube applicator to the chain, squeezing as you backpedal. After you are finished applying the lube, back pedal about six more times, then wipe off the excess using a clean rag. If your chain is dirty, the rag will soak up dirt and excess lube. Use a cleaner side of the rag and continue wiping excess lube and dirt off the chain by pedaling backwards with one hand, holding the chain with the rag in the other.
- Riding on the Chain: Your riding style will affect how long your chain will last. If you ride in a high gear, the lower cadence loads the chain more than if you spin in a lower gear. The less the chain is loaded, the longer it will last. Reducing the amount of cross gearing (large chainring and large cog in the rear or small chainring and small cog in the rear) will also help improve the life of your chain. If you ride a tandem, your chain will most definitely wear faster.
It is important to remember that your new chain be compatible with the drivetrain on your bike. There are multi-speed and singlespeed chains. Check with your local bike shop about which chains they carry and which one will work with your bike. With bikes from a single gear all the way to 30 gears, getting the right chain is very important as one might not work with the other.
Understanding your drivetrain is valuable knowledge for all cyclists. Taking a little extra time to understand how it works will make you a more confident and knowledgeable cyclist and an asset to your riding partners. If you are interested in learning more or having some hands-on experience with your drivetrain, The Broke Spoke does maintenance classes that are catered to you. Minimum participants for a 3 hour class is 2 at $20 a person. Call or email The Broken Spoke for more information or to schedule your class.
