Reach BikePro on a 24 hour basis at 803-280-1537 Terry Dunbar is on duty as the technical expert, who also speaks Spanish as well as English and has quantities on hand information. Call her now for any questions about Bike Pro you may have.
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Reach BikePro on a 24 hour basis at 803-280-1537 Terry Dunbar is on duty as the technical expert, who also speaks Spanish as well as English and has quantities on hand information. Call her now for any questions about Bike Pro you may have. |
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Bullseye Roller Bracket
The Bullseye Rollerbracket is a fixed spindle with dual floating cups type of bottom bracket. This is a divinely crafted bottom bracket that uses needle roller bearings instead of ball bearings. With ball bearings, whether in a retainer or in a sealed bearing cartridge, only the very top and bottom of the upper and lower most balls support the weight of the rider at any moment. That puts a very small area under a great deal of pressure. Roger Durham at Bullseye designed the Rollerbracket to dissipate the pressure over a greater area. Needle bearings are shaped like tiny metal rods. They carry the weight over the length of the rod (needle) with it's multiple points. They are placed side by side around the axle, rather than the ball bearings 'singular point. The Rollerbracket is held in place using threaded, Silver aluminum retaining cups, that have parallel flat surfaces ground into them for tool grip. Installation doesn't require a special spanner wrench, in fact you could carefully use any adjustable wrench to install this bottom bracket. As a floating type of bottom bracket, lateral adjustments are simple. An internal, locking aluminum collar, locks the spindle into the correct position prior to final needle bearing cup installation. The bearing cups have an oil passageway built into them, that permits relubrication in minutes. This can be used with many cranksets, both double and triple chainring, depending on the spindle length. The spindles for this unit are measured in inches, and are available in 4 1/2 (109mm), 4 3/4 (121mm), 5 (127mm), 5 1/4 (133mm), or 5 1/2 (139mm) inches long. The weight of the Rollerbracket in the 5 inch (127mm) size, is 316 grams (with crank bolts, which weigh 27 grams). Truly unique, rock solid, made in Burbank, California. English thread only. Spindle Length-09-21-27-33-39 $Price in Catalog |
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In-depth Information About Metals Aluminum Aluminum is extracted electrolytically from bauxite ore. It is made by the electrolysis of aluminum oxide which is found in larger concentrations within bauxite ore. Bauxite is a mixture of the hydroxides of aluminum, together with other impurities such as oxides of iron, titanium, and silicon. Bauxite is produced by the weathering and change of aluminum silicate rocks usually found in tropical and semitropical regions where climate has produced an accelerated weathering process. Bauxite is not a rare ore and is widely available in the US, the Caribbean, and Europe. Approximately 4 pounds of read the full article... Beryllium Beryllium is a specialty metal that is steel-grey metal in color, with an extremely low density, making it very light weight. At 1.85 grams to the cubic centimeter, its density compares to that of magnesium. It is also a high strength metal, making it possible to design light weight, thin membered parts with ahigh stiffness. A column made of beryllium to support a load placed directly downward on top of it, will have a greater load carrying capacity, and be lower in weight than any other metal of equal size. Until the 1950's beryllium was used read the full article... Titanium The element titanium was discovered in 1763 by an English cleric, William Gregor who was an amateur chemist with an inquiring mind. It was in the black sands of Cornwall that he discovered the new element that had up to that time, attracted little scientific interest. A few years later, an Austrian, Klaproth, extracted the same element from an ore widely known as "rutile", which is a mineral consisting of titanium dioxide (one titanium atom, two oxygen atoms), that is a reddish-brown substance with a slight metallic luster. While rutile is the highest grade read the full article... Metallurgic Hardness Testing There are three types of tests used with accuracy by the metals industry,they are the Brinell hardness test, the Rockwell hardness test, and the Vickers hardness test. Hardness is the property of a metal which gives it the ability to resist being permanently deformed (bent, broken, or have its shape changed), when a load is applied. The greater the hardness of the metal, the greater resistance it has to deformation. Since the definitions of metallurgic ultimate strength and hardness are rather similar, it can generally be assumed read the full article... |
