What is a UDH?

UDH is an abbreviation for Universal Derailleur Hanger. It is a system developed by SRAM to standardize the hangers used in mountain bikes. This system was introduced by SRAM in 2019 and since then many mountain bike brands have started incorporating it into their designs.

If a rider has a bike with a UDH compatible frame and the hanger breaks, they can get a replacement UDH hanger from almost any bike shop.

The SRAM universal derailleur hanger consists of two parts - the derailleur hanger itself and the UDH screw that attaches the derailleur hanger to the dropout. Some frames may require a UDH frame washer. It is therefore advisable to ask the frame manufacturer whether this is required.

What is the purpose of a derailleur hanger?

A derailleur hanger is an important part of a bicycle that protects the rear derailleur and frame from damage in the event of a serious impact. The hanger is structured to allow it to bend or break to prevent costly damage to the derailleur. This not only extends the life of your bike but also helps you save money.

What is special about the UDH Hanger?

The UDH is a clothes hanger specifically designed for use with thru axles. Although it shares some similarities with existing hangers, it also has some unique features that are still patent pending. One of its outstanding features is that it prevents the chain from falling off the smallest sprocket. Even if your rear derailleur hits a rock, the UDH can rotate backwards, protecting both your frame and your rear derailleur. In addition, the UDH is manufactured to meet the specifications of all major MTB derailleurs currently available on the market. It's right in the middle of every rear derailleur specification. This means that not only does it work with any front derailleur, but these front derailleurs are also already optimized for UDH.

compatibility

The Universal Derailleur Hanger (UDH) is an excellent choice for mountain bikers who want to use a range of groupset manufacturers, including Shimano and Box, rather than being limited to SRAM derailleurs. This gives consumers the freedom to choose from different components when building or upgrading their bike. SRAM's decision to make the UDH compatible with other brands has made it a more universal and widespread option in the industry. Since its launch in 2019, many mountain bike brands have started producing UDH compatible bikes. To make it even easier for customers, SRAM has provided a bike finder tool on its website that allows them to check whether their frame uses the UDH standard.

Is the SRAM UDH compatible with my bike?