What is SRAM UDH?
This Article By Oscar Huckle (From bikeradar)
The derailleur hanger is a sacrificial part that connects the rear derailleur to the dropout. In the event of an impact, the derailleur hanger is designed to bend or break, protecting your rear derailleur and frame.
For many years, derailleur hangers were frame-specific. If you broke one, it would often mean a trip to the bike shop, where the workshop would rummage through drawers of hangers to find a replacement – or they would have to order one in.
That changed when SRAM launched its Universal Derailleur Hanger (UDH) standard in 2019.
In this guide, we’ll take you through what exactly SRAM UDH is, how it works, bike compatibility and how to remove and install the hanger.
What is SRAM UDH?
SRAM UDH is designed to unify derailleur hanger standards.
SRAM says consolidating different hanger designs makes replacing a bent hanger easier and helps optimise shifting because there are fewer variables.
Like many other hangers, the UDH is made of two parts – the hanger itself and what SRAM refers to as the ‘UDH bolt’, which secures the hanger to the dropout.
On some frames, you’ll need to use a ‘UDH frame washer’ between the hanger and bolt. It’s worth consulting your frame manufacturer to check if it’s required, although it’s generally used on split-pivot designs from brands such as Devinci, Orbea, Salsa and Trek.
