If you ride your bike on the streets of Chicago (or anywhere else, for that matter), you will at some point experience the dreaded drivetrain wear. The drivetrain of your bicycle consists of the chain, and all the parts that it touches: the front chainrings, rear cassette, and front and rear derailleurs. This whole system is what makes the bike go, and yet it is often the most overlooked aspect of bicycle maintenance.
Under normal riding conditions, the continuous tension on the chain causes it to gradually stretch (how? click here for a detailed explanation). Add moisture, dirt and salt from the road, and you accelerate the destruction.
You can assess the condition of the chain through a scientific process known as empirical observation.
Eyeball the chain. Is it slick and shiny? Then consider yourself lucky. If it's black and goopy, or dry and rusty, things are not good.
Feel the chain between your fingers. If it's very sticky, or brittle and stiff, you've got problems.
Measure the chain. You can do this with the chain on the bike. Place the zero point of an accurate ruler in the center of one of the pivot pins on the chain, and measure out 12 inches. On a new, unworn chain, the 12" mark falls in the center of a pivot pin. If the pin on your chain falls beyond the 12" mark, use the following guidelines:
- if the distance is less than 1/16", no problem, just clean and oil your chain regularly (see below)
- if the distance is 1/16", you will need to replace the chain, but probably not the sprockets
- if the distance is 1/8", you will need to replace the chain and the cassette
- if your chain is worn beyond this point, you may even need to replace the front chainrings, or at least the one you usually use.
That's right. Unfortunately, the chain does not wear alone. With use, it causes uneven wear on the cassette and front chainrings. A worn cassette (and in more extreme cases, the front chainrings) will not work with a new chain, and has to be replaced.
The good news is that you can prevent untimely drivetrain demise by keeping it clean and well-lubricated, and replacing worn parts promptly.
If your drivetrain is dirty, clean it with hot, soapy water, using household dishwashing detergent, a bucket and a stiff nylon brush. (Please do not take your bike to a car wash, as the hoses use excessive pressure.) Scrub all parts throughly, and repeat, if necessary. Rinse and rag off thoroughly.
Once the chain is clean, apply a good quality bicycle lubricant to each chain link, and to pivot points on both derailleurs, and rag off excess. DO NOT use grease, household oils, WD-40, motor oil, etc. on your bicycle chain. These will attract a lot of dirt, and actually cause the chain to wear faster. There are plenty of good bicycle lubricants on the market, so you can take your pick. If you consult the mechanics at Rapid Transit for a recommendation, you are likely to get a different answer from each one, but we only carry high-quality lubricants formulated for bicycle chains, so you can't go wrong.
If you prefer to avoid intimate contact with your drivetrain, treat your bike to a session at our "Bike Spa". We'll do all the work, sometimes even while you wait. We also offer drivetrain cleaning as part of our premium tune up service.
You can also visit us anytime for a free chain lubrication.