From: jobst.brandt@stanfordalumni.org
Subject: Re: how do you know if sprocket is worn?
Newsgroups: rec.bicycles.tech
Message-ID: <y5%8c.2033$Fo4.22625@typhoon.sonic.net>
Date: Fri, 26 Mar 2004 19:00:46 GMT

Eddie who? writes:

> Hi, Is there a way to inspect a sprocket to see if it is too worn?
> My new chain skips on one particular sprocket (6th gear) on MTB.

That's the test.  If it skips under load randomly whenever pedaling
hard, its the sprocket.  If the chain skips approximately once every
time the chain makes one complete revolution, it's a tight or an
unlubricated link in the chain.

The way to test for a tight link is to manually turn the derailleur
idlers so the chain is semi slack and turn the cranks backwards.  A
tight link will remain angled when it comes of the derailleur wheel as
it moves forward on the bottom run of the chain.

To fix a tight link, bend the chain sideways forcefully, an action
that tends to spread the side plates and increase clearance.  Using a
super-link gets around this problem.  In fact most people don't push
in pins on their bicycles so tight links are not so common a problem
anymore.

Jobst Brandt
jobst.brandt@stanfordalumni.org