Ritchey Cranks


	

RITCHEY LOGIC COMPACT CRANKS

A set of compact cranks is in the future for the majority of mountain bike riders. Since Suntour introduced them in the 1991. Their benefit in reduced weight, stiffness in chainring, faster shifting, and the chainstay clearance of the smaller diameter outer have been obvious. Ritchey couldn't ignore the trend for long and the Compact Logic cranks are the result. The Logic Compact uses the Shimano compact bolt pattern of 94mm for the bolt center diameter for the middle and outer chainrings, and 58mm for the inner chainring. The cranks are, again, manufactured by Sugino in Japan for Ritchey. The arms are cold forged of aluminum alloy with flat a face and sides making defects and damage from wrecks easy to spot. The cold forging process makes consistently stronger aluminum forgings so these cranks have an added strength advantage. After the initial forging, which gives the arm its shape and the 2 degree tapered interior for the B/B spindle, the holes are drilled for the dust cap, fixing bolts and pedal spindle. As an added step to make the hidden fifth arm, a saw cut is made to the back side of the right arm so that an 8.5mm kerf left afterward allows access for fifth fixing bolt.


	

The dust cap hole is tapped with 22mm x 1mm threads and the pedal spindles are tapped with the 9/16" x 20 TPI threads. The arms are given a fine hand polish on the face and sides, (the back of the arms is left relatively untouched), then the arm is clear silver) anodized.





The chainrings used for the middle and outer are the "SuperShift" variety, which employ particular bends of the chainring plate and cuts to the rear or the teeth to assist in quick shifting and chain engagement from the inner and middle chainrings. The outer chainring is die-cut from 2.65mm thick plate aluminum. The cutting process adds some bends, as corrugation to the chainring giving it added rigidity. Once die-cut, the chainring is turned on a lathe to reduce the material thickness of the teeth area to 2.0mm and taper the front and back of the teeth. The outer has an aluminum anti-jam pin driven into it.

	

The middle is die-cut from 2.67mm thick plate andturned on a lathe to reduce the thickness at the teeth to 2.0mm. The middle chainring has even added more bends and corrugation, with special cuts to the rear of the teeth to facilitate chain rise from the inner and delivery to the outer chainring. Both the outer and middle have been anodized in a pinkish Grey (metallic salmon) that might be referred to as WCS. The inner chainring is made of stainless steel. The mid/outer fixing bolts and nuts are made of nickel plated steel as are the inner bolt set. The Logic Compact cranks come with a set of crank bolts that are copies of the Shimano capless design. These are made of plated steel with an 8mm hex fitting for their installation or removal. Each bolt comes with a Black snap-around dust cap. Together, the bolt and cap have a 13 gram weight, you will still require a crank arm pulling tool to remove the aluminum arm without damaging it. We found the Logic Compacts had a Bike-Pro Q measurement of 154mm. The Compact is available in 170mm, 172.5mm, 175mm, 177.5mm or 180mm, with a choice of 22-32-42 or 22-32-44 tooth chainrings. The weight of a set of Logic Compacts in the 175mm length was 667 grams.

	Length 70-72-75-77-80 - Rings 22-32-42=2/22-32-44=4 $ Price in Catalog



Ritchey Logic Road Cranks
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