SRAM PG-1070 Cassette Lockring - 12T $8.00
If you're constantly adjusting cassettes, fine-tuning your gear ratios for the race ahead, then more than likely the soft aluminum threads and locking teeth are wearing out. Keep a SRAM PG-1070 Cassette 12T Lockring handy to ensure your cassette won't come loose when sloppy shifting is the last thing you need to happen. This lockring is only compatible with 12T cassettes; you'll need a smaller one for 11T units. It's made from forged aluminum, it's anodized, and has laser-etched logos.