Perhaps no single component can have a greater effect on your cycling experience than your bike cassette. Choose the right one, and you will have the perfect gear range to both sail quickly downhill and efficiently spin up steep climbs. But opt for the wrong bike cassette and you may find yourself spun out when descending and/or over-geared when going uphill.

How then do you pick the right one when there are over 70 choices alone on JensonUSA.com? It starts with understanding how bike cassettes work. Each one is actually a group of cogs (think machined wheel of metal with teeth that engage a chain) that determines the range of gears you have for both maintaining speed on downhills and flats, and efficiently spinning up climbs.

When your chain is in a smaller cog (with fewer teeth) it is harder to pedal but your bike will travel at a faster speed. Conversely, when in a larger cog (with more teeth) it is easier to pedal, allowing you to keep your cadence high while ascending.

Thus, cassettes are typically represented by the lowest and highest number of teeth in that cluster of cogs. For example, most common road bike cassettes have ranges such as 11-25, 11-28, 11-30, and 11-32, all of which are made by Shimano and SRAM, the two largest cycling component makers. On the mountain bike side SRAM’s Eagle wide-range 10-50 cassettes are very popular, though you’ll also soon be seeing a 10-51 offering as part of the new Shimano XTR groupset.

Of course not all cassettes will work with all bikes and their respective drivetrains. Distinctions include mountain bike (think Shimano XT, Shimano XTR, SRAM Eagle) versus road bikes (SRAM Red, SRAM Rival, Shimano Dura Ace, Shimano Ultegra), and also the number of speeds (or gears/cogs), which these days is usually 11 for road bikes and 11 or 12 for mountain.

JensonUSA offers bike cassettes from every major brand, covering all the varying options. If you have questions, call one of our Gear Advisors today at 951-234-7554. They’ll be happy to help you find the perfect cassette for your bike.