By Owen Gerrard
Illustrations by Chris Simonen
Part #2: The Derailleur
In this dandy mechanics column we will explore each part of the bicycle individually, and examine what special role it plays in making your whole machine run smoothly.
In part one, we looked at the chain; we turn our attention now to the derailleur.
Derailleur: it’s more than just a very difficult word to spell. Your derailleur is on your bike waiting for you to embrace its extremely accommodating self into your daily bicycle ride. As a bike shop employee, I cannot in any way, with any sort of exaggeration, overstate the number of times someone has said to me, "I don't need that many gears," or my favourite, "I don't even use my gears."
I have always felt that derailleurs and gears as a whole get a bad rap as being difficult or hard to deal with. Rear derailleurs especially, as these sit in a prone place on the bike (hanging on the outside of the frame near the rear wheel). Locking up your bike in a pile or having it fall to the drive side (where the chain is) of the bike can lead to a bent derailleur. Bent derailleurs don't work properly, they miss gears, pop, click, and sometimes slip entirely.
Derailleurs are all about making situations better. What a derailleur does is to allow you to move the bike chain (please see our last dandyMECHANICS column) onto different cogs in your drive train. By moving the chain onto different cogs the derailleur allows for the creation of various gear ratios. These gear ratios change the way it feels to pedal your bike. For instance, if you use your derailleur to move your chain from the largest diameter cog on you rear wheel to the smallest you will feel an increase in resistance when you pedal.
Derailleurs always rest in the smallest cog and move up into larger cogs. The derailleur works by using a shifter (usually mounted on your handlebar), which is attached to the derailleur by a shifter cable. You pull the cable to shift while a spring in the derailleur pulls back to return the chain to the smallest cog.
Advanced maintenance for a derailleur usually centres on set up and adjustment of cable tension. For this kind of maintenance it is very important to seek experienced help. There are many ways to fiddle or adjust a derailleur; limit screws, bead tension bolts, cable retention bolts. Knowing how to balance these adjustments takes experience, as proper set up varies bike-to-bike and situation-to-situation. For basic upkeep, keep your derailleur clean, lubricate the pivot points and prevent crud from building up on the pulley wheels.
As an avid bicycle gear user I would like to offer forth a simile, which I hope will help relate my position to others. Let’s replace the bike in this conversation with a toilet and the derailleur with a toilet seat. While I can understand that some people might not use a toilet seat, I believe that most people would not argue that a toilette seat can make some, let’s say, situations, easier to deal with. Derailleurs are like toilet seats in that they make certain situations easier. Use them.
About the author:
In 1995, Owen Gerrard began his first stint as a bike messenger. He had been riding avidly for a couple years so the transition to biking-for-pay was an easy one. He got his first bike shop job in 1999. Since then he’s done almost all the jobs available at busy bike shop, stock boy, coffee fetcher, mechanic, sales, sales manager, purchaser, general manager. His approach to bikes is a practical one. He doesn’t believe in magic fixes or miracle solutions. He believes good habits and simple maintenance are all you need to keep a bicycle running well for a long time. He is currently the manager of one of the dandiest bike shops in town, Sweet Pete’s.
Related on the dandyBLOG:
Sweet Pete’s will adhere reflective tape to your bike for free – if you contribute to our dandyCOMMUTE series! Send us your story and photos today and you will be entered into a draw to WIN A BIKE at the end of 2013.
Sweet Pete’s now at two locations: photos by Molly Crealock