How To Adjust Your Front Derailer

QuickTime version of How To Adjust Your Front Derailer

Applies to most 3-chainring derailer systems.

Tri-Flow Park AWS-11C Park SK-1 Park AK-37

Today we’re going to learn how to adjust the front derailer. Make sure that you’ve already set up your rear derailer, as you will need to access all of your rear gears for this tutorial.

Front Derailer Components

Front Derailleur

Height Adjustment

The first step is to adjust the derailer’s height and angle using the positioning clamp that attaches the derailer to your bike’s frame. This can be a bit tricky, since tightening the clamp’s bolt will set both height and angle at the same time. To make things easier, tighten the clamp so that it is secure, but loose enough to move it around with your hand.

Front Derailer and Chainring

For correct height adjustment, position the bottom of the derailer cage as close to the largest sprocket teeth as possible, so that it still clears. Manufacturers recommend a 2mm spacing, but this is only meant as a general guide and not a rule. The lower the cage is, the better it will shift. While you’re in this position, take a quick look at the curvature of the large chainring and the outer derailer cage, to make sure no part of the cage is rubbing on the chainring.

Angle Adjustment

The derailer angle is set by looking down from above. This can be tricky and requires some patience, as the shape of the derailer cage is often not straight. You’ll want to imagine a centerline in the middle of the cage, which should line up with the center line of your frame. Once the angle is correct, you can completely tighten the positioning clamp.

Limit Screws

There are two gear limit screws. On older derailers the low-gear limit is closest to the frame, but some newer models have reversed the screw’s positioning.

Low Gear Limit

To adjust the low-gear limit, first make sure your chain is shifted to the largest sprocket in the rear, and the smallest sprocket in the front. The low-gear limit stop stops the derailer from shifting past the smallest chainwheel and throwing the chain onto the bottom bracket shell. If it is too loose, the chain will fall off when you downshift to the small chainring. If it is too tight, it might not shift down at all. Ideally, you want to set up the inner plate so that it barely clears the chain in the lowest gear. However, triple chainrings like this one sometimes require a tiny bit of extra spacing.

High Gear Limit

To adjust the high-gear limit, shift the chain into your highest gear, that is, smallest sprocket in the rear, and the largest sprocket in the front. The high-gear limit prevents the chain from shifting past the largest chainwheel and throwing the chain out into your pedals. Ideally you want the cage to stop just after it clears the chain on the large chainring.

Shifting Adjustments

Now that both limit screws are set up, shift back to the largest sprocket in the rear, and the smallest in the front. Make sure your front shifter is in the lowest gear position, and pull the shift cable to eliminate any extra slack, before tightening the cable bolt.

Shift the front derailer to the middle gear, and run through the entire range of rear sprockets to make sure the chain does not rub on either side of the front derailer cage. If it does rub, you can adjust the trim by tweaking the barrel adjuster on your front shift lever. If you have an older friction shifter, often you will have to manually adjust the trim while riding.

This tutorial was based on the most common type of drivetrain, and assumes that you are using the components your derailer was designed for. If you have a customized set of chainrings and/or derailers, you may need to try some different techniques, or even take your bike into a shop for further adjustment.

Adjust Front Derailer

Resources


Bike Repair Guide » Derailer, Drivetrain, Front Derailer, Gears


9 Responses to “How To Adjust Your Front Derailer”

  • toujoursraison

    Thanks mate, keep on your good work!

  • Tony

    Thanks for the help, worked great! I didn’t think I’d be able to do it myself!!

  • ladicius

    Thanks for this just what i needed better than them poxy haynes manuals.

  • Niallo

    Alex,

    Great website and very very informative, well done. However, i do have one snag for all these excellent tutorials:

    Not everybody owns the type of bike stand that you use for your tutorials. Nor will anyone be carrying one while touring for example.

    So, would you have any hot tips for a DIY stand to replicate what you can achieve with your own stand?! I was thinking of some way to just support the back wheel while leaning the bike against a fence etc. The bike could of course be turned upside down, but this can be quite awkward, especially for changing gears, plus it can be damaging for light/speedometer mounts.

    Any tips would be great!

    Niallo

  • Alex

    Thanks Niallo,

    No problem, I am planning to do a work-stand / home tools guide… I’ll let you know when it has been posted!

    Alex

  • Exactly what I was looking for. Thanks!

  • Kevin

    If i can’t even shift to the highest gear on the front does that mean its the high limit adjustment thats off ?

  • Alex

    Kevin, it sounds like your high limit screw is too tight, or that your cable needs more tension. Try tightening the cable first - if the derailer stills stops at the same spot, try loosening your high limit.

  • Hoot

    Niallo,

    Here are a couple good options for making repair stands:

    http://www.instructables.com/id/PVC-Bench-top-Bike-Repair-Stand/

    http://www.yourmtb.com/story/build_your_own_bike_repair_stand_for_under_20

    I’m currently throwing together the second one.