Everything you need to know about the Universal Derailleur Hanger (UDH)

Until recently, derailleur hangers were frame-specific: each bike brand designed its own hangers and usually there were even differences between frames. Multiply the number of bike brands by the number of frames and you know the extent of the problem. After all, when this part broke, you had to go to the bike shop. There, the repairman headed towards the many cabinets and drawers hoping to find a spare part. With thousands of types on the market, that was a downright nightmare.

That problem is now a thing of the past, courtesy of the UDH, an innovation from US bike parts manufacturer SRAM. The UDH replaces the infinite number of different hangers. This development makes attaching the derailleur much easier. When a cyclist with a UDH-compatible frame breaks the hanger, they can find a replacement UDH in almost any shop. To integrate this UDH into the frame, manufacturers just need to provide a specific shape.

(From left to right: the UDH on Falcn RS, Grifn A, E-Grifn and Grifn RS):

The UDH consists of the pendant itself and the 'UDH bolt', which attaches the pendant to the dropout. Sometimes an additional ring is used, but that depends on the frame supplier. The thru-axle also has to be of sufficient length, of course. The UDH is compatible with all major brands, such as SRAM, but also Shimano and Campagnolo. Later, SRAM also came out with the 'Transmission', where a derailleur is not attached to a hanger, but rather directly to the frame.

Moreover, the UDH also means optimising shifting performance on all bikes. Indeed, by standardising the fixed position of the derailleur, the UDH ensures a better and more consistent shifting experience. In addition, the UDH will pivot backwards in the event of an impact, providing protection for the frame and derailleur. The design falls right within the specifications of any major MTB rear derailleur. Finally, the UDH prevents the chain from getting caught between cassette and dropout. When the chain slides off the smallest sprocket onto the cassette, a hook-shaped lip pushes the chain back on.

By now, the UDH is already the most common derailleur hanger ever produced. In just a few years, the component conquered several segments. All a bike brand has to do to make use of it is to apply for a licence. Every month there are more bikes integrating the UDH and Ridley was always the trendsetter in this. Especially with the Grifn A, the UDH is a standout feature. You rarely see this on aluminium bikes at the moment. In this way, we underline that we also want to build modern bikes with all the innovations in this price segment.