WORKSHOP: How to fix trashy gears

This issue we thought we’d talk you through a few issues that can cause bad shifting. Whether that’s slow, sluggish shifting - or not working at all.

AMB Magazine 06.12.2017

I’ll start with the most common issue. Bent hangers are one of the most frequent problems we see in the workshop when it comes to bad shifting. One small hit, or stack on the drive side, and your hanger will most likely be bent. You should be able to tell by looking down the bike from the rear wheel. This will generally cause the gears to become out of index, prevent you from staying in gear or result in clunky un-smooth shifting. To remedy this problem, you will either have to own a hanger-straightening tool (which is a good one to own) or pop down to your local shop to have it looked after.

Words: Joe Dodd   Photos: Chris Herron

HIT THE LIMIT
If you know your hanger is straight and you are having problems with the chain dropping over the back of the cassette, you will need to look at the limit screws. These stop where the rear mech can be shifted.  These should be set inline with the smallest and largest cog on your cassette.

FEEL FOR TENSION
The B tension screw adjusts where the rear mech sits away from the largest cog on your cassette. It is the extra 3rd screw that you will see on your mech. Too far away and it will cause sluggish shifting in the smaller cogs. Conversely, if it’s too close it will create issues shifting in the larger ones.


DAMAGED GOODS
Damaged cables also cause lots of problems. Both inner and outer cable damage will result in all sorts of issues when it comes to smooth shifting. Replacing a cable will make a huge difference to how your bike shifts. Look out for old, split outer cable end caps, damaged outer housing, and also rust. Inner cables can also cause issues. Make sure you don’t have any kinks. Older inner cables may also fray and start to snap. Keep an eye out for this.

 
LOOK FOR KINKS
Always make sure that your housing isn’t too short. You want a nice curve coming into your rear mech, no sharp kinks (as pictured). You also want to make it long enough at the front so you can turn the bars without it binding up and long enough that you can get max travel without it becoming too short.
 
LOVE YOUR DRIVETRAIN
Worn out drive trains can be a real pain, resulting in skipping, miss shifts, slow shifts, clunky shifting, and dropped chains. Keep an eye on your chain and change when appropriate. The more often you change your chain, the longer the rest of your drive train will last and perform as it should. A worn cassette will cause slow clunky shifting, especially if you have recently put a new chain on it. Worn jockey wheels will cause slow shifting and these are quite often overlooked, so be aware.