Review on BOLANY 9 Speed Cassette Review: The Perfect Fit for Mountain Bikes and Road Bicycles, Ultra-Lightweight Design by Richie Kotun

This review is a cassette, not an extension. Upgraded my outdated 3x9 setup to a 1x9 and needed an inexpensive cartridge. I bought the 11x42 version, installed it with no problems, I was pleased with the smooth switching. I've tried many different cassettes (SRAM, Shimano, Microshift, etc.) and this one shifts just as smoothly as most. I installed the included hanger extension first, but after trying to bend it a bit to accommodate my crooked hanger, it broke. I bought another (heavier) extension and now enjoy a wide range of gear perfect for local trails.