Cassettes

Mountain Bike Cassette Buyer's Guide

The cassette is the cluster of chainrings located on the rear hub, directly above the rear derailleur. The number of rings, or cogs, on the cassette multiplied by the number of front chainrings determines how many gears a bike has (ex: a 9 speed cassette with 3 front chainrings = 27 speeds). Cassettes come in a variety of gearing ratios intended for different applications, and are commonly designated by the number of teeth on the smallest gear and the biggest gear (ex: an 11-34 cassette). The high end of the cassette with more teeth will help riders on up steep climbs, whereas the smaller number allows for a higher maximum speed. Cassette choice depends on a bike's chainring setup and riding style.

Types

Cassettes are all quite similar and easily installed on the freewheel body of most rear hubs. A cassette's gearing ratio can make it better for certain applications. Many downhillers choose to run road cassettes because of the tighter ratio and because they have no use for a "granny" gear (the largest gear used for climbing). All-mountain riders running one chainring will want cassettes with a large range between high and low gears in order to climb and descend effectively without a front derailleur. Cross-country riders may also want a wide selection of gears and opt for a similarly geared cog. Standard cassette gearing ratios range from 11-23 to 11-36.

Sizes

The majority of cassettes all fit the standard size freewheel hub body. It is important to verify the number of gears and match it with your shifter and derailleur. Cassettes are available in 6, 7, 8, 9, and 10 speed sizes.

Materials

Entry-level cassettes are made of steel, and as they become more expensive cassettes use aluminum and titanium to save weight and increase shifting smoothness.

Things To Look For

There are a few key things to take into account when replacing a worn out component or upgrading to a new shifter and derailleur system. The first is the number of gears. The amount of cogs on the cassette must coincide with the number of clicks on the rear shifter: 6, 7, 8, 9 or 10. Next, you must choose a suitable gearing ratio. If it is a simple replacement and you were satisfied with your old setup, then installing a new cassette with the same ratio is the way to go. If you felt the ratio wasn't right, with either too much disparity between gears or not enough leverage in the granny gear, you may benefit from a cassette with a different gearing ratio. Finally, if you are replacing the cassette as an upgrade, you may want to look into lighter models.

How Much To Spend

Cassettes range in price from $15 to $200.

In the $15-$35 range, cassettes are one-piece steel or aluminum designs that emphasize durability and value over performance and weight savings.

Moving up to the $40-$75 range, cassettes begin to shed weight and increase shifting performance thanks to more sophisticated designs and manufacturing techniques. In this range, cassettes are equipped with specially machined shifting points to drastically improve shifting speed and fluidity.

Above $100, cassettes use titanium cogs and multi-piece carriers to dramatically reduce the total weight of the component while using the most precise machining technology available.

Product Reviews

Before buying, be sure to do your research and read product reviews. Reviews are a great way to find out specifics about a particular model, user impressions, and things to watch out for. After you've purchased a product and had enough time to thoroughly test it, we encourage you to leave a review for other people to see when they are researching bikes and parts on the web.

We hope you've found this information to be helpful. If you have a question that isn't answered in this guide, our mountain bike forums are a great place to get advice from knowledgeable riders. Your local bike shop is also a great resource.