The Ritchey Logic crankset
is made in Japan by Sugino (who also makes the cranks sold under the
Specialized name), following Ritchey's specifications. The crank arms
are among the first of Sugino's new cold forged products. Each of the arms
is high polished by hand on the outer face, top and bottom sides, (the
rear of the arm is lightly polished, the rear of the spider isn't at
all) then clear (Silver) anodized. The arms have a flat surface for the
face, top and bottom, making stress fractures easy to spot.
To reduce weight,
one of the five arms on the spider section of the right crank arm, has
been eliminated. The fifth
arm on the Ritchey crank, actually exists on the back side of the crank
arm itself, where the spider, and the arm meet. The crankset was designed with a low Q-factor as
an objective. These Mountain cranks are said to have a 151mm Q factor,
which is the distance from outer crank facing to outer crank facing with
the two arms properly and securely fastened to a B/B spindle. The end of each arm, at the pedal end has the backside
rounded slightly, to provide greater chainstay clearance. The left arm
is forged with a point, leaving extra mass around the B/B spindle. This
extra aluminum helps displace stress on an area historically prone to
stress fractures.
Included with the
cranks are chrome plated steel crank bolts that have affixed chrome dust
caps. These bolts have an 8mm hex fitting for removal and installation. A steel washer
is included for the cap/bolt to turn against reducing friction. The
bolt weighs 16.5 grams, the washer another 2.5 grams. Using a crank arm
pulling tool (Park CCP1) will still be necessary to remove the arm
without damage. The crankset comes with Silver anodized aluminum
chainrings, and all necessary fixing bolts.
The outer chainring
is die-cut from 3.66mm thick aluminum plate, then turned on a lathe to
taper the teeth, and then the teeth area to 2.06mm thickness. The outer
chainring has an anti-jam pin pressed into it at the crank arm, to
prevent the chain from bunching up between the arm and rings in an
overshift. The middle is die cut from 3.30mm aluminum plate, turned on a
lathe to taper the teeth and thickness to 2.03mm. The inner made the
same as the middle. The chainrings use the standard 74mm and 110mm
fixing bolt pattern. Because the "fifth arm" of the spider is really the
crank arm, standard outer chainring replacements with an anti-jam pin
won't have the pin usefully line up correctly on the Logic Crank.
Replacement with a "Ritchey" or a 110mm BCD outer designed for fifth arm
cranks will be necessary to maintain the anti-jam pin functionality.
The Logic Mountain cranks come with nickel plated steel middle outer
fixing bolts and nuts. The inner set of fixing bolts is also nickel
plated steel.
The cranks will work
with any 2 degree, tapered spindle, bottom bracket. Provided with 24-36-46 tooth chainrings. Logic cranks come as right arm, left
arm, three chainrings, all the required fixing bolts, and a set of crank
cap/bolts. Logic 175mm cranks with all included parts, weigh 714 grams.
The steel crank arm cap set weighs 38.5 grams a pair. |