Shimano Deore 9-speed chain ring FC-M590/591

The influence that the chainring has on the function of the derailleur is often underestimated. To obtain original Shimano shifting performance, Shimano cranksets should only be fitted with the original Shimano chainrings. Only these chainrings are exactly designed to work perfectly together and with the appropriate Shimano chain as a composite. Functional features such as special tooth profiles, ramps and climbing aids achieve a consistently precise, clean switching function at the front.



Hyperdrive:

Shimano's front shifting system is based on the HyperDrive concept. Derailleur, HG chain and SG-X chainrings work in a coordinated combination and make shifting ahead more reliable, faster and more accurate. Without HyperDrive, problems quickly arise, especially under load, when switching from the middle to the large chainring. Shimano's HyperDrive system eliminates these problems. The guide teeth, the SG-X chainrings, the super-stiff Wide-Link derailleurs and the special profile of the HyperGlide link plates have been designed to work perfectly together as a system, ensuring clean, trouble-free shifting. The chainrings have exceptionally high torsional strength. The profile of the teeth is specifically shaped so that when shifting in both directions the chain can slide and be picked up cleanly.

Hollowglide:

Hollow outer chainring. The highly stable hollow construction reduces weight without losing strength. Better power transmission and faster, more precise chainring changes are the result.