· By Johannes Olsson
Derailleur hangers: the small part that saves your frame
The derailleur hanger protects your frame in a crash – but the right model is hard to find. With the BikeParts app you photograph the hanger and get the right part in seconds.
The derailleur hanger – your bike's crumple zone
It's one of the smallest parts on a bike, but also one of the most underrated. The derailleur hanger sits between the frame and the rear derailleur and effectively works as your bike's crumple zone. If the worst happens – a crash, the bike toppling over or taking a real knock – the hanger is meant to bend and break first.
The design is brilliantly simple. Instead of the force going straight into the frame and causing an expensive cracked frame, the small, cheap part that the hanger actually is gets sacrificed. The derailleur and hanger take the hit, while the frame survives. That's exactly why you should treat the hanger as a consumable – not a fault to avoid, but a safety mechanism doing precisely what it should. As small as it is, it's that important.
A derailleur hanger is cheap. A new frame is not.
Always keep a spare
Because the hanger is built to break, it's smart to always keep one at home. Being caught without it mid-season can mean a simple crash leaves the bike standing for weeks – all for the sake of one tiny part.
After a knock it's also important to check that both the hanger and the rear derailleur are straight. A bent hanger causes real trouble:
- The gears jump and refuse to index properly
- The chain can slip or even drop off
- In the worst case you risk knock-on damage to the rest of the drivetrain
If the hanger is bent it should be replaced, not bent back and forth. The metal fatigues quickly and can snap exactly when you least expect it. A spare hanger costs a fraction of a needless workshop visit – think of it as cheap insurance that takes up almost no space in the toolbox.
Find the right hanger – photograph it with BikeParts
Here's the catch: there are almost as many derailleur hanger models as there are bike models. Brands like LaPierre, Scott, Trek, Nishiki and Crescent all have their own variants – and the mounts differ depending on model and year, too. A tiny difference is all it takes for a part not to fit.
Getting it right has long been pure detective work. With our app BikeParts we flip that around. Take off your old hanger, photograph it – and the app matches the right part in seconds. No guessing, no needless wrong orders, and time saved for both you and the workshop. For a bike shop that means faster answers at the counter and happier customers who aren't left waiting on the wrong part.
Still can't find the right one? Have the brand, model and year ready and we'll help you on to the correct hanger.