Gear changing trouble? Check this.

For a couple of weeks my gear changing on the rear derailleur has been inconsistent and unpredictable and very frustrating! Sometimes no change at all after actuation of the handlebar lever, sometime a jump of two, and occasionally jumping off between two rings. This is often accompanied by grinding and clicks, clangs. Upsetting because I was always impressed how silky smooth the changes had been on this bike which I’ve had for over 10 years. Tik, tik, tik up. Tik tik tik down. Beautiful!
It can be dangerous if the gear shift is not a decisive action. If pedal force is applied and the chain is not properly engaged, the unexpected violent jerk can cause a serious crash.

After checking all the obvious, removing kinks and relubing the gear change cable, repeated adjustment of the actual derailleur, even dismantling the handlebar actuator (don’t do this!), I was at at loss. What to do?
To fill in time I decided to remove the rear wheel and clean up the rear cluster. After applying degreaser I started to brush it clean and immediately noticed it was quite loose! It only took a moment to tighten up the retaining ring and after a test ride, voila! It was back to its silky smooth operation once more. (Cleaning often discloses real and potential problems!)

That's about 40Nm

I think that’s about 40Nm!

The retaining ring said to tighten to 40Nm. If I had done this when I fitted the cassette, I would not have had the above hassle. Nm is short for newton metres. To get a feeling for how tight this is; a newton is near enough to 100 grams. So 40 Nm is the turning force of 4kg at the end of a metre long spanner.
Or for a longish spanner of around 330mm, 12kg or so is needed.

Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>