Derailers for Dummies (Bike Week)

Barrel adjuster on rear derailleur

May is National Bike Month, which we at your friendly neighborhood Antisocial Network have been celebrating this week by pointing out clueless freelancers pretending to give advice about bicycles. Perhaps the richest vein of dumbassery on any topic can be found at eHow.com, especially the early content submitted anonymously. In those days, the How (Not) To articles bore only the byline "eHow Sports and Fitness Editor," such as today's article, "How to Fix a Poorly Shifting Bicycle"¹ (now attributed to "Contributor" by Healthfully.com)

According to that long-anonymous writer, "There are only two factors that affect [a] derailleur's function: cable tension and derailleur alignment." We won't argue with that statement because it's a simplistic version of true (omitting for now, the possibility of worn cogs and chainrings). What we will argue about is Anon's instructions on how to adjust cable tension:

"Find...the cable coming from the handlebar... use an Allen (hex) wrench to undo the nut or bolt that secures the cable. Using only your hand, pull the cable taut... While holding the cable taut, resecure the cable with the nut or bolt."

Among the staff of the Antisocial Network there are usually five or six bicycles kicking around the office, and our chief bicycle mechanic laughed until coffee came out his nose when he read the instructions from eHow. Once he'd stopped howling and had cleaned the spilled coffee off everything in the room, he asked -- rhetorically, we assumed -- "Doesn't this dumbass know about the barrel adjusters on the shift cables?"

That's right, people: you don't need to pull the cable tight by hand any time except when you've just installed a new shift cable. After the cable has been correctly installed, you use the barrel adjusters to fine-tune its tension and periodically take up any slack caused by the cable's natural tendency to stretch. Otherwise, you don't mess with it. You definitely don't adjust cable tension by loosening the cable clamp and hand-tightening! As for the instructions for using the limit screws (the entire second half of Anon's article)? Well, they're sort of correct - but not correct enough to get satisfactory results. It's pretty clear from this dumbass' description that he thinks turning the screws "adjusts" the derailleur alignment - it doesn't, it merely changes the range through which the derailleur moves.

Once more, eHow demonstrates why thinking people everywhere avoid the advice of its freelance dumbasses like the plague, and why the site collects Dumbass of the Day awards like dog poop collect flies.

¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was   ehow.com/how_117871_fix-poorly-shifting.html

copyright © 2015-2022 scmrak

DDIY - BICYCLES