Park Tool Co. FR-5

Park FR-5 Cassette Lock Ring tool

I once did a supported 4000 mile ride from NY to LA on a brand new bike. That was nice.  Beside a flat or two the only mechanical problem I had was the cassette lock ring backed off of the 10 speed cassette. I realized this when I shifted and the chain dropped down completely between two of the cogs. This was just a small problem because nothing was lost. I just took off the wheel, took the loose cogs off and cleaned them with a rag since I had the chance. Then I lined them up in place and spun the lock ring on. This tool was not in my kit at that time but I did have a flat head screwdriver. I used that to get the lock ring tight enough to get back on the road for a few miles. After reaching the SAG, I used this tool to tighten it back to spec.

Now I have one of my own.

I want to weld a 15mm nut to the back side so I don’t have to carry a one-inch socket to turn this thing.

Made in USA

parktool.com