This is a Harris Cyclery exclusive, designed by Sheldon Brown, using Shimano sprockets.
This is intended to provide nice low gears and still preserve reasonably close spacing in the cruising range, without wasting gears by devoting space to ludicrously high gears. This is intended to be a good match for bikes with traditional "full sized" chainrings.
It is generally good practice to replace the chain when you replace the cassette.
We recommend the SRAM PC-951 chain for use with this cassette.
This cassette will index with any Shimano-type 9-speed shifter, but does require a wide-range (touring/mountain) rear derailer.
This cassette will fit any Shimano 8- or 9-speed hub.
After beating Lymphoma and surviving 6 cycles of chemo, I converted one of my rides (Titanium Litespeed Vortex) into a performance "cafe" touring bike. I lost much of my fitness and muscle mass and basically had to re-train from scratch. The 12-27 cassette I had on there was perfect when I could hammer up the hills at a cadence of 80-85, but now, I struggle and even have to stop midway on some of the climbs around where I live. I thought about converting my 39-53 crankset to a "compact" 34-50 but it looked like too expensive a solution. My research led me to the Harris' Cyclery site and Sheldon's 13-34 "cyclotouriste" cogset was the answer. I test-rode it today and the gearing was perfect for the undulating, rolling terrain we have around here. The 34 did the trick on a couple of 8-9% grade hills on my regular route. I did not change the chain on my Dura Ace gear train and noticed rhythmic clicking when I was on the 3 lowest cogs. It seemed to get better after 25 miles. I think I will polish the teeth on my power wire brush and see if that solves the problem. Other than that, I think this cogset will prevent knee injury while I'm training to get back into shape.