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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No Longer Made
JOE MURRAY IMPACT HEADSETThe Impact headset has many of the features that have become headset buzz words, "headlock", and "oversized bottom bearings". Let's start at the top. The headset is designed by Joe Murray and made in Taiwan by YST. This doesn't use a headlock and head key washer in the common sense. It has a single piece made of machined aluminum and steel that is the equivalent of the head lock nut, head key washer, and upper cup race. This piece features a clamp to lock this upper headset piece down on the fork steer tube, in fact it's done like the Mavic 315 headset. There is a cut at the top of it with a 5mm allen bolt that passes horizontally to draw up and cinch the head lock nut firmly in place. It has a clever thread-in plastic stem seal on the top of the lock nut device. The steel upper cup race is ground and then painted black. Because of the complexity of this upper piece, the only practical way to create the cup that covers the bearing is to make it as a separate piece and fasten it to this machined top piece. This shroud piece is made of plastic and is held in place by a cone race that is pressed onto the head lock device. The bearing retainer in the assembly uses twenty-two 5/32" bearings. The fork crown race seems to be stamped steel which has a ground bearing surface that is painted Black. The lower bearing cup is steel, which is polished, then painted Black. The bearing retainer in the lower assembly uses fifteen 1/4" bearings. The oversized lower bearings can accommodate more abuse and should produce longer wear. The lower assembly is surrounded by a molded, yet removable rubber "bearing boot". In the early days of mountain biking, dirt contamination in the headset was common. Adequate seals didn't exist yet. Pioneer MTB riders would cut a 1 inch section out of an old tube and use it to vertically enclose the headset assemblies as a seal to keep dirt out. The Impact's rubber boot is designed to do this more efficiently. The 1" version weighs 148.5 grams and has a stack height of 39 mm. Black only. Joe Murray now works for Titec replacing Mr.Bontrager and the Impact headset is no longer imported by Kona. They now sell the Control Center headset. We sold both sizes of the Impact for $24.99 |
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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... |
