Last updated: March 15, 2024
Frequently Asked Questions about derailleur mech hangers: What is it or what are derailleur hanger types ; How to identify it; How to use our derailleur hanger finder or find your bike derailleur hanger.
If you did not find answer to your question here please feel free to Contact us. We are experts in derailleur hangers and ready to answer to any of your questions.

What is derailleur hanger ?

Derailleur hanger is a replaceable bike part that connects the rear derailleur to the bike frame. Rear mech hanger is attached to your bike using bolts, screws or sometimes lock nuts/rings and then bike rear derailleur itself bolts on to the mech hanger. Almost all modern bikes with gears have it.

Older steel frames could have permanent dropouts which is strong as frame and are not replaceable. There are many derailleur hanger types , but our rear derailleur hanger finder helps to identify the bike hanger correctly with no time.

Derailleur hanger with frame

Derailleur hangers are also known as rear mech hanger, gear mech hanger, gear hanger, mech hanger, dropout, frame saver, soshanger, rear mech derailleur hanger, schaltauge, forcellino cambio, ausfallenden, mecanico desviador percha, graxeira, Переключатель вешалка, Hak, 变速器挂钩, perjungėjo auselė, велосипедный петух, держател заднего переключателя, אוזן, dia schaltaugen, patte de dérailleur, patilla de cambio, puntera cambio, petuh, patka, gancheira geardrop, pata, petukh, cережка на раму, serga na ramu, fusible repuesto, pata cambio bicicleta, koncovka patku na ram, auusfallende, hak przerzutki do ramy, hak rowerowy, koncovka, ureche schimbator, derailleurpad and others.

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 using gear hanger finder - read more about our finder 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.

VIDEO: How to replace derailleur hanger with 12 mm thru axle video...

VIDEO: How to replace derailleur hanger with QR axle...

What is the purpose of gear mech 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.

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 gear 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 / types of manufacturing them: Cast, stamp, forge or CNC machined aluminium. The highest quality and precision has CNC machined types of 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 rear derailleur hanger finder is easy - finder helps to  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)
    Derailleur hanger types - Inside vs Outside
  3. By axle diameter (Standard QR, 10 mm, 12 mm):
    Derailleur hanger types - Standard QR vs 10 mm vs 12mm
  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-link

Direct mount derailleur

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.
    Emergency derailleur hanger with beer opener
  2. For Though axle (12mm) systems: Emergency derailleur hanger | DROPOUT-G.
    Emergency derailleur hanger for thru axle

How to find the correct derailleur hanger for my bicycle using derailleur hanger finder ?

To find the right derailleur hanger you will need:

  1. Remove your original derailleur hanger from frame. It is quite easy process and can be done with few regular hex wrenches (also called an Allen wrench). First remove bike rear wheel, then release and remove bolt connecting derailleur with derailleur hanger. In last step with smaller hex wrench release one or more fitting gear mech hanger screws and remove derailleur hanger from frame.
    • If you are not quite sure which part is your bike derailleur hanger? The answer is: it’s the small, thin, ussually silver or black color metal piece that connects frame to your derailleur. Or just do an online image search for “derailleur hanger” or “rear derailleur hanger.”
    • In case you can’t remove the current gear hanger for some reasons, don’t worry — you still have options! Contact us  with high-quality photo of the installed mech hanger or bring your whole bike to a bike shop.
  2. Search for a derailleur hanger using derailleur hanger finder with advanced Elanus Parts filtering system:
    • Filter by derailleur hanger fitting holes number/-s (1, 2, 3, or others);
    • Filter by derailleur hanger mount side on frame (Inner, Outer, Clamp or others);
    • Filter by derailleur hanger inner step shape (Straight, Curved, No step or others);
    • If you know your rear wheel axle type you can filter by it, as well as derailleur mount type (direct or standard).

    Derailleur hanger finder

  3. If for some reasons you didn't find needed hanger with our mech hanger finder filtering system or you are not sure if this the right one, feel free to contact us and send your derailleur hanger photos. We will find it for you.

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