Frequently Asked Questions about derailleur hangers

What is the purpose of derailleur hanger?

Bicycle rear derailleur hanger is designed with purpose to break or bend in order to prevent or limit damage to bicycle frame or other drivetrain components in case of accident: crash, drivetrain failure an others.
Derailleur hanger with frame

Why are derailleur hangers important?

The derailleur hanger is relative cheap (10-30 Eur) and essential part of your bike – it should be checked and quickly replaced when necessary. Riding your bike with a bent or damaged rear gear hanger could cost hundreds of Euros to repair / replace its damaged components: damaged bike frame, drivetrain parts.

The sos hanger makes easy to repair and re-align the derailleur without possibility to destroy the derailleur/drivetrain system or bike frame. We always recommend have spare gear hanger somewhere close to you or your bike. Find a spare part at Elanus Parts huge range from most known and reliable derailleur hanger manufacturers: Pilo precision machining, Marwi and Wheels mfg.

Why does derailleur hanger breaks or bends?

Derailleur hanger usually breaks or bends as a result of accidentally derailleur hit to surrounding object when riding, in case of crash or just when trying to align the bent gear hanger. Also, there are exceptional cases of mech hanger break when changing gears with big force on to pedals, for e.g. climbing a very steep mountain and trying to quickly change gears. Also could be initially weak design from sos hanger manufacturer, in most of these cases we have reinforced versions for e.g. derailleur hanger D673.

How and from what derailleur hangers are made?

Derailleur hangers (dropouts) generally are made from relatively soft aluminum. There are few ways of manufacturing them: Cast, stamp, forge or CNC machined aluminium. The highest quality and precision has CNC machined derailleur hangers.

CNC derailleur hanger vs Cast derailleur hanger

CNC machined sos hangers are made from higher quality aluminium mark  6061 T651. Bike equipped with these hangers have more precise gear shifting, looks greater and possible goes faster :). Derailleur hanger identification at Elanus Parts is easy - find sos hanger in a minutes.

What are rear derailleur hanger types?

There are thousands derailleur hanger types (designs) on the market. Every frame manufacturer could have different sos hanger design for each model of frame and different sos hanger for same frame but manufactured on different year. So when search replacement for your gear hanger you must be sure that hangers design is exactly same to original. If still have questions or need assistance please contact us.

There are many ways to classify types of derailleur hangers:

  1. By number of fasteners (1,2,3+):
  2. By mounting side (inside frame, outside frame, clamp/fork and other)
    Outside fitting derailleur hanger vs Inside
  3. By axle diameter (Standard QR, 10 mm, 12 mm):
    Standart QR vs 10 mm vs 12mm derailleur hangers
  4. By derailleur mounting method:
    1. Standard
    2. Standard with adapter ("B-link", "Goat link") 
    3. Direct mount

Standard derailleur mountStandard derailleur mount with adapter/B-linkDirect derailleur mount

What are universal emergency derailleur hanger types?

There are two types of universal emergency derailleur hangers:

  1. For QR (9/10mm, 5mm skewers) axle systems: D99 universal derailleur hanger with beer opener.
    Universal emergency derailleur hanger for QR axle
  2. For Though axle (12mm) systems: Emergency derailleur hanger | DROPOUT-G
    Universal Emergency derailleur hanger for through axle

How to replace a derailleur hanger?

If your derailleur takes a hit during the ride, the derailleur hanger (sos hanger) purpose to absorb the impact. If the gear hanger gets bent or damaged, you will need to replace it. First you need to identify and get compatible derailleur hanger replacement. Read more here.

You'll need a hex wrench (usually 5mm on standard hangers), bike cleaner, and bike grease. This is quite easy process to replace new derailleur hanger and make shifting perfect again. Anyway, if you unsure always contact your local bike shop mechanic.

To change / replace your bike derailleur hanger follow next steps:

  1. Take off the rear wheel of your bike.
  2. Loosen and remove the bolt that connects the derailleur to the hanger. There is no problem to let the derailleur hang from the shift cable while you work.
  3. Loosen and remove derailleur hangers fitting screw(-s) that holds it to the frame. Some hangers have from 1 to 3 or more screws to unscrew to remove the hanger.
  4. Before installing the replacement derailleur hanger, clean off the frame area where hanger was attached.
  5. Then lubricate inside and outside of the frame with small amount of grease.
  6. You can install the new hanger now. Tighten it into place. Grease up the threads on the derailleur mounting bolt and reconnect the derailleur. It's best to use a torque wrench to tighten the bolt to the manufacturer's specified torque.
  7. Re-install the rear wheel and make sure the gears are shifting normally. If not re-adjust gear shifts.
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