The Dura-Ace 7410, is the successor to the DA 7402 crankset. The 7410 is Shimano's top-of-the-line Road Racing crankset and is Shimano Total Integration (STI), HyperDrive and Dual SIS compatible for use with their narrow chain. These are cold forged arms, a process where the aluminum is first cut into the rough shape of the final piece and squeezed several times into it's final shape, making a denser alloy arm that is less susceptible to stress fractures. The arm is then drilled, broached the B/B spindle, and tapped for the 9/16" pedal spindle and the crank arm dust cap. After the front of each arm and the rear to the spider area has been given a fine polish, then clear (Silver) anodized, the front of each arm has the Dura-Ace logo silk screened in Black on it. (Previous versions had the logo engraved then painted Black, after anodizing). The right arm has the reverse side milled in the area of the spider leaving nice clean edges with no extra aluminum to increase weight. The arms have a flat surface so any bends are very noticeable, and in not painting the arms, it is easier to discover cracks and fractures from crashes. At the crank bolt, the arm is rounded reducing mass. The chainrings are precision cut and ground for an exact chain fit, then Silver (clear) anodized. The large chainring has an anti-jam pin driven into it where the chainring lays over the crank arm. This is to prevent, in an overshift, the chain from jamming up between the chainring and the arm. With the anti-jam pin it's possible to push the shift lever forward and re-engage it on the large chainring. The outer chainring also has SG-X teeth at three locations, which is a combination of 5 teeth that have small steel pins in a notch cut into the chainring back.
These SG-X "gates" are said to improve the speed of shifting from the inner to the outer chainrings. The chainrings are round and have 130mm bolt spacing. Included with the arms are two crank arm bolts, which are made of two parts machine pressed together. The larger of the two is Titanium that has an 8mm hex fitting for removal or installation. An aluminum outer dust cap is pressed onto the outer end of the bolt. To reduce friction a steel washer is used for the crank bolt to rotate against. An other weight reduction feature of the 7410 set is chainring fixing bolts and nuts are made of aluminum. The cranks are a low profile design will work with any 2 degree tapered spindle bottom bracket that has a very short spindle. Shimano strongly recommends using their 103mm long spindled 7410 B/B. Other makers with a 103mm length should as well. Dura-Ace 7410 cranks are made in 170mm, 172.5mm, 175mm, 177.5mm, or 180mm lengths, occasionally with patience we can special order a set in a 165mm or 167.5mm length. They come with the 42-52 or 39-53 tooth chainrings. The Dura-Ace 7410 cranks come as right arm, left arm, two chainrings, all the required fixing bolts, and a set of Ti/aluminum crank arm bolts. The 175mm 42-53t crankset, with all included parts, weighs 598.5 grams (down from the previous 647 grams). Specify length and chainring sizes. $ Price in Catalog
The Shimano 6400 Ultegra crankset is made of aluminum alloy and appears to be a forged of molten aluminum. After the forging the arms, any roughness or "flash" is milled away. The back side of the spider of the right arm is milled to remove excess aluminum and produce a clean, uniform look. The arms are drilled for the B/B spindle, the crank arm dust cap, pedal spindle, and also, on the right arm, fixing bolts, (130mm spacing). The hole for the B/B spindle is broached to make the 2¡ tapered sides, then the dust cap and pedal spindle holes are tapped with threads. Each of the arms is then polished on the front, top, and bottom, (the rear is left largely un-polished), Clear (Silver) anodized, then screened with the Shimano logo. The Ultegra crankset has round Superglide chainrings with cut down teeth at the top and bottom of the pedal stroke to improve shifting. Shimano, in an effort to reduce the "Q" factor has made the Ultegra crank with a low profile spider. The inner chainring rests farther over the bottom bracket shell, using a shorter, and therefore stiffer B/B spindle giving the crankset less flex in the B/B. Ultegra cranks come with two aluminum alloy chainrings that are die-cut to shape then turned on a lathe to taper its thickness from 3.61mm to 2.02mm. The die-cut teeth are stamped to create the point, tapering the front face of the teeth. The two teeth most responsible at the top and bottom of the pedal stroke for the SG shift are left shorter and milled to shape. Both chainrings are Silver (clear) anodized. The outer chainring has an anti-jam pin driven into it to assist, in case of overshift. Nickel plated steel fixing bolts with 5mm hex fittings are used to fasten the cranks and chainrings. The crankset comes with two chrome plated plastic crank arm caps that have black rubber O-rings to seal out dirt. Though the holes for the dust caps are tapped with 22mm x 1mm pitched threads, the provided dust caps are a press-in type. All after market aluminum replacements are compatible. The cranks will work with any 2 degree, tapered spindle, bottom bracket. Shimano recommends a 113mm B/B spindle length for a 68mm English B/B shell and a 115mm for a 70mm Italian B/B shell. We stock Shimano Ultegra cranks in 170mm, 172.5mm, or 175mm lengths with the 42-52 or 42-53 tooth chainrings. We can special order them in 165mm or 167.5mm lengths but it might take quite some time for delivery. The Ultegra 6400 cranks come as right arm, left arm, two chainrings, all the required fixing bolts, and a set of crank arm caps. The 175mm 42-53t crankset, with all included parts, weighs 685 grams. The 172.5mm 42-53t crankset, with all included parts, weighs 676.5 grams. Specify length and chainring sizes. $ Price in Catalog
This is one of the best priced, quality road racing cranksets on the market. The 105SC arms appear to be forged using molten aluminum alloy in a casting process. The arms are drilled for the dust caps, fixing bolts, the B/B and pedal spindles. The arms are then broached to make the 2 degree taper for the B/B spindle. The arms are tapped with 22mm x 1mm threads for the arm dust caps, and the needed 9/16" threads for the pedals. Both the right and left arms are painted with a glossy Silver-Grey enamel finish, (discerning defects or fatigue because of the paint is made more difficult, but the expense of polishing is avoided). The current version of the 105SC cranks bear the Shimano part number of FC 1056 (Front Chainwheel 1056) which comes with a set of the Shimano "capless design" crank bolts. These bolts, made of Chrome plated steel, have an 8mm hex fitting built into the bolt/washer which allows removal and tightening of the bolt with a long handled (for leverage) hex wrench (you will still need a crank arm pulling tool to remove the aluminum arm without damage). Around the exposed crown of each 13 gram crank bolt is a snap-on plastic Grey plastic dust seal. The 105SC cranks come with two aluminum chainrings that are die stamped to shape and turned to reduce the 2.83mm thickness to 1.97mm on the front side of the teeth. After milling the tops of the teeth are struck or stamped to make the necessary points. These are SuperGlide round chainrings, to be used with any chain, including Shimano's HyperGlide. The outer chainring is the SG-X type with paired tiny steel rivets within crimped areas of the chainring to assist in lifting the chain onto the large chainring occurring in three positions. It also has an anti-jam pin. The chainrings are then Silver (clear) anodized. Nickel plated steel fixing bolts with 5mm hex heads are used to fasten the cranks and chainrings to the 130mm bolt center diameter patterned arm. The 105SC cranks will work with any 2 degree, tapered spindle, bottom bracket. Shimano recommends a 107mm length spindle for either a 68mm or 70mm B/B shell. This arm set had a Bike-Pro Q measurement of 153mm. We stock Shimano 105SC cranks in 170mm, 172.5mm, or 175mm lengths, with the 42-52 or 42-53 tooth chainrings. We can special order them in the shorter 165mm or 167.5mm lengths but it may take quite some time for delivery. 105SC cranks come as right arm, left arm, two chainrings, all the required fixing bolts, and a set of "cap-less" crank arm caps. The 172.5mm 42-53t crankset, with all included parts, weighs 695.5 grams. Specify length and chainring sizes. $ Price in Catalog
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