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Ritchey Logic Brake Levers


Because the Ritchey levers are made by Dia-Compe in Japan and they entered the market after the SS-5 but before the SS-7 we are placing the review here. Their construction is similar, and they use the same parts with slightly different shaped forgings for the handle and clamp sections. The handle and clamp sections are made of cold forged 6061-T6 aluminum alloy.

The handle section is held onto the clamp assembly using the same bolt and nut found on both the SS-5 and the SS-7. The nylon washer set used to reduce the sliding friction between the handle and clamp section is the same set of two used in the SS-5. For a lever return spring, the Ritchey levers use the type found in the SS-5 set, which is coiled around the bolt and washer set. One end of the spring is mounted in the handle and the other end pushes against the interior of the clamp section housing. The lever fastening bolt, clamping the lever to the handlebar, is the same used on both the SS-5 and SS-7 levers. The steel bolt has 6mm by 1mm threads, an 18mm length, a 5mm hex fitting for tightening and a 4.5 gram weight.

The Logic lever uses the same two piece cable barrel adjuster set found on both the SS-5 and SS-7. The adjuster is made of aluminum with a 3.5 gram weight and 7mm by 1mm threads. A plastic nut on the adjuster holds its place once the adjuster has been used to properly tighten the slack out of the cable.

The aluminum adjuster is left in its natural aluminum Silver color on the Logic while it is Black on both Dia Compe SS levers. The has a 100mm length from the center of the bolt holding it to the clamp section to the tip and has a 65mm length for the finger grip area. Like the SS levers, the Logic has a small steel set screw to adjust the travel or "throw" of the lever. Tightening the screw reduces the distance the handle section travels until it stops when released. Turning the screw clockwise makes it easier for smaller hands to use. The clamp assembly of the Logic lever is always Black, but the handle section can be either Black or left Silver. Unlike the Dia Compe SS lever sets, the Logic set comes with a set of Dia-Compe BRS mountain brake cables. The pair weight of the Logic levers is 181.5 grams. The cables are discussed in the cable section of this article. Made in Japan.

Black/Silver $ Price in Catalog
Black/Black $ Price in Catalog
WCS/Silver $ Price in Catalog





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...


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