Road Bike Crankset
Cranksets receive more abuse than any other part of the bicycle. In short, cranksets are responsible for 100% of the power transfer from a rider to the bike. All of the energy you produce must go through the crankset to produce forward momentum. As you might imagine with a part so crucial to the performance of the bicycle, manufacturers offer a seemingly endless array of cranksets, all claiming to improve performance. In reality, only so much can be done to improve a crankset, so here is our attempt at cutting through some of the marketing noise to help our customers pick a crankset that suits their riding style. At WesternBikeworks.com we carry cranksets made by Campagnolo, Shimano, SRAM, Easton and Fulcrum.
While manufacturers continuously claim to reinvent the crankset, they remain fairly simple components. Cranksets are composed of three primary parts: Cranks arms, Chainrings and a bottom bracket. The first two items are fairly self explanatory, bottom brackets are the cartridge that fits into the frame itself and houses the bearings which facilitate the pedaling motion.
When purchasing a crankset, you are essentially getting crank arms with chainrings attached. Bottom brackets are sometimes included, but that varies from brand to brand. Chainrings are removable and able to be replaced when worn, which generally takes several years. Different size chainrings can also be swapped, though sizes are limited by the size of your crank arm spider, which we'll get to when we discuss compact cranks.
A good crankset should be light and stiff. Bike parts are generally ruled by the 2/3rds rule. Pick two: light, durable(stiff), cheap. It can be light and durable, but not cheap; if it's durable and cheap, it's not light, etc.
Carbon vs. Aluminum
As with all bike components these days, high performance cranksets can be made from aluminum or carbon fiber. In general, carbon cranks run a bit lighter than aluminum. Aluminum cranksets are generally more rigid.
Shimano has been the last holdout in the carbon crank wars. For years, Shimano maintained that they would not produce a carbon crank that lacked the stiffness of their flagship aluminum Shimano Dura-Ace FC-7900/50 Crankset. The Shimano Ultegra SL FC-6601/6650-G Crankset and Shimano 105 FC-5600/5650 Double Crankset level cranks are perfectly adequate for all but the most competitive cyclists.
Easton Has recently entered the crankset game with their new Easton EC90 Carbon Crank. According to Easton these are some of the stiffest and lightest cranks on the market. Using their Carbon Nanotube Technology they have kept the weight down and the strength up, of course with all of this R&D comes with a price.
Most every crankset will get the job done. Lighter cranksets will tend to be more expensive. If your main concern is durability and stiffness, go with aluminum. If your goal is a light, sexy, eye-catching ride, carbon cranksets will get you there.
Triple vs. Compact
Traditionally, recreational and touring riders often chose a crankset with three front rings rather than the standard two. This provides more low end gears for comfortably getting over climbs, while maintaining a 53-tooth large ring for powering across the flats. The Campagnolo Race Triple 10 Speed Crankset is a great Triple at a very good price. Triples are especially useful for touring riders carrying large loads, but for the average rider, triples give a much wider gear ratio than necessary and add quite a bit of weight. Enter compact cranksets.
Compact cranksets have provided one of the more useful component innovations in the past decade. Essentially, compact cranksets provide smaller, easier to push front gears. Standard cranksets typically provide 53-39 front rings while compacts utilize 50-34. But compacts provide much more than just "Granny Gears".
With proper cassette selection (usually 11-23), compact cranks actually provide more "useful" gears than standard cranksets. While powerful pro's and competitive racers rely on Their 53x11 gearing for intense sprints, most riders have little use for anything above a 53x14. Compact cranks provide a wider range of the small and mid-range gears used in climbing and tempo riding while only giving up the largest gears. Compact cranks provide more efficient gearing and generally weigh less than standard cranks, and much less than a triple crank.
There is a significant mechanical difference between standard and compact cranks. It lies in the length of the crank arm spider. Crank spiders are measured by BCD, the "bolt circle diameter". Standard cranks utilize a 130mm BCD while compacts use a 110mm. Chainrings fit one or the other, not both. Compact cranksets also often utilize a special front derailleur, the FSA Compact Front Derailleur is designed to accommodate compact cranks. Shimano front derailleurs are compatible with either.
We highly recommend compact cranks to all but the most accomplished racers. Compact cranks provide versatile gearing where you need it most, reducing muscle fatigue and making your ride more comfortable. Feel free to contact us at email@example.com or 1-800-651-4050 with any questions regarding crankset selection and compatibility.