Marwi and me: The A to Z of gear hangers

Marwi explains the all the things you were too embarrassed to ask about gear hangers, including what they’re really for, how they’re made, why there are so many different kinds, and why they’re so hard to source

What is a gear hanger?

A gear hanger, or derailleur hanger, is a small aluminium plate that is assembled between the derailleur and the aluminium or carbon frame – steel frames don’t use gear hangers. The shape of the gear hanger corresponds with the shape of the frame’s drop-out section. All gear hangers used by bike manufacturers are made from AL-6061 cold-forged aluminium, and are case-hardened to a specific hardness. The function of the gear hanger is to protect the frame for external impacts by accidents or “chain-blocking”. The force of impact is absorbed by the gear hangers, and as a result the hanger will bend or break. This is to avoid more serious damage to the frame.

How are gear hangers made? Most bike brands do not produce their own frames. These are made by a number of bike frame makers, mainly situated in the Far East. The drop-out sections and the corresponding gear hangers are mostly designed by the frame makers (sometimes in cooperation with the bike designers) and are made by specialised cold-forging manufacturers. Frame makers receive the complete cold-forged drop-outs with the hangers as a ready part, and they use them as the basis for the frame.

Why are there so many different kinds of gear hanger?

Of course, every bike model has its own frame design, otherwise all bikes would look exactly the same. Due to different frame dimensions, frame specifications, chain lines, derailleur systems and many more technical details, the shape of the drop-out and the hanger has to vary. Frame makers have a number
of standard drop-outs for bike brands from which to choose. But many bike brands have designed their own drop-out system over the last ten to 15 years.

The major frame manufacturers deliver frames to many different bike brands. Since standard drop-out systems are used by these frame makers, the corresponding hanger is used by many different bike brands. Especially in the last five
years, a lot of mountain bikes are equipped with a thru axle (M12x142mm) that needs a special design for the drop-out and the hangers. All the major bike brands designed their own thru axle drop-out system. Nowadays there will be around 500 to 600 different shapes of gear hangers in the European market, used by some 200 different bike brands.

Why are gear hangers so hard to get your hands on?

Most bike brands do not service their dealers with a complete range of gear hangers. Some bike brands do have a compatibility list for all their bike models, but most don’t make that kind of information publicly available. In daily practice, that means that whenever a new gear hanger is needed, the bike shop (or the consumer) needs to find the right hangers from the market. For some of the most standard hangers, this can be done without too much hassle. But for hangers that are less standard than others, the search can end up becoming a time-consuming gear hanger nightmare.

So, what’s Marwi doing to solve this problem?

In 2014, Marwi set up a database for the whole cycle industry to use, collecting the information for which bike brands and models require which gear hangers. Information was gathered from
the cold-forging manufacturers, the frame makers and, last but not least, from the bike brands themselves. The information has been organised on Marwi’s website on a user-friendly platform, allowing the bike shop (or consumer) to find out which gear hanger they need in just a few clicks.

First of all, the search engine on Marwi’s website allows you to search for all the specific bike models and model years that are listed for every bike brand in alphabetical order. In the case that the bike model is not listed, you can also check a clear photo overview with each and every gear hanger that fits frames from that specific bike brand. You can also search by the assembly style of the hanger. Based on criteria like “assembled from inside” or “assembled from outside” and the number of screws used, a selection can be made from the total available assortment of hangers, to find the correct hanger.

How widely is the tool used?

Step by step, the database on Marwi’s website has been built up to more than 7,000 frame models today. The website and its search engine can be used in ten different languages and is accessed by thousands of bike shops and end-users every day. Marwi’s website is not a webshop; it is more like an online catalogue with a search engine. That means you can not order the hanger from Marwi’s website, but with just one or two extra clicks bike shops can see where to order the hanger they need. Before ordering, clear photos from both sides can be used for double checking. Moreover, technical drawings can be downloaded and printed at a scale of 1:1 to compare the bent or broken hanger.

Where do Marwi’s gear hangers come from?

Currently Marwi has a range of 219 different gear hangers which covers approximately 80 to 90 per cent of the European market. All these hangers are made by the very same cold-forging manufacturers that also supply the original hangers to the frame makers. For all standard hangers that fit multiple bike brands, Marwi’s hangers are the same as the originally-used units. For most brand-dedicated hangers that are exclusively made for the major bike brands, Marwi opened their
own tooling with the same cold-forging manufacturers, securing a perfect fit and
correct case hardness. So, a
gear hanger from Marwi is equivalent to the original hanger.

Free poster and catalogue 

Marwi is offering retailers a large poster (80cm x 110cm) that displays the complete range of hangers and brake pads. The poster is available in many different languages can be added to any workshop wall to take away any headaches of finding the right component. The poster also lists the wholesalers that Marwi cooperates with so the mechanic can contact them easily to purchase parts. The poster is currently being distributed as a supplement in the most popular bicycle trade magazines. Marwi also supplies a free catalogue to retailers that contains a complete and comprehensive range of components with lots of additional information.

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