Snap Ring Tools
Not many snap ring tools fit the M4 snap rings on the SRAM derailleurs, because most tools have tips that are too large and far apart to fit the small snap ring size.
The snap ring tool should have these characteristics:
- The tips should have 0.8mm to 1.0mm diameters. If the tip diameters are 1.2mm or larger, they wont fit into the snap ring.
- The tips should be parallel to each other. This prevents the snap ring from slipping off the tips. If required, you can gently bend the tool until the tips are parallel.
- The tips should be able to come in contact with each other. This allows them to fit inside the snap ring so you can open it. If required, you can grind material off the tool (just don't grind the tips) so the tips can make contact.
- Ideally it should have an adjustment to limit how wide the tool can open. This is very helpful to prevent deforming the snap ring, which will result in an un-reliable installation. If your tool does not have this, you have to be very careful when opening the snap ring to prevent deformation.
The best snap ring tool we are aware of is the Knipex 49 31 A0. It has all the characteristics above and is available for under $30 USD from many online retailers. We've done a lot of work trying to find a similar one at a lower cost, and have not found one. There are a few others for $20-$25 USD, but they do not have adjustment to limit the opening width, and often require modification to get the tips to be parallel and in contact with each other.
Madrone also still offers our snap ring tool. We offer it to make the purchasing experience simple, and offer an alternative in case the Knipex 49 31 40 is not available in your area. Our tool has all the characteristics above.