Sprocket

INSTALLATION AND USING

The chain spocket, as a drive or deflection for chains, has pockets to hold the chain links with a D-profile cross section with flat side surfaces  parallel to the centre plane of the chain links, and outer surfaces at right angles to the chain link centre plane. The chain links are pressed firmly against the outer surfaces and each of the side surfaces by the angled laying surfaces at the base of the pockets, and also the support surfaces of the wheel body together with the end sides of the webs formed by the leading and trailing walls of the pocket.

NOTICE

When fitting new chainwheels it is very important that a new chain is fitted at the same time, and vice versa. Using an old chain with new sprockets, or a new chain with old sprockets will cause rapid wear.

It is important if you are installing the chainwheels yourself to have the factory service manual specific to your model. Our chainwheels are made to be a direct replacement for your OEM chainwheels and as such, the installation should be performed according to your models service manual.

During use a chain will stretch (i.e. the pins will wear causing extension of the chain). Using a chain which has been stretched more than the above maximum allowance causes the chain to ride up the teeth of the sprocket. This causes damage to the tips of the chainwheels teeth, as the force transmitted by the chain is transmitted entirely through the top of the tooth, rather than the whole tooth. This results in severe wearing of the chainwheel.
 

FOR CHAIN STANDARDS

Standards organizations (such as ANSI and ISO) maintain standards for design, dimensions, and interchangeability of transmission chains. For example, the following Table shows data from ANSI standard B29.1-2011 (Precision Power Transmission Roller Chains, Attachments, and Sprockets) developed by the American Society of Mechanical Engineers (ASME). See the references[8][9][10] for additional information.

ASME/ANSI B29.1-2011 Roller Chain Standard SizesSizePitchMaximum Roller DiameterMinimum Ultimate Tensile StrengthMeasuring Load25

For mnemonic purposes, below is another presentation of key dimensions from the same standard, expressed in fractions of an inch (which was part of the thinking behind the choice of preferred numbers in the ANSI standard):

Notes:
1. The pitch is the distance between roller centers. The width is the distance between the link plates (i.e. slightly more than the roller width to allow for clearance).
2. The right-hand digit of the standard denotes 0 = normal chain, 1 = lightweight chain, 5 = rollerless bushing chain.
3. The left-hand digit denotes the number of eighths of an inch that make up the pitch.
4. An "H" following the standard number denotes heavyweight chain. A hyphenated number following the standard number denotes double-strand (2), triple-strand (3), and so on. Thus 60H-3 denotes number 60 heavyweight triple-strand chain.
 A typical bicycle chain (for derailleur gears) uses narrow 1⁄2-inch-pitch chain. The width of the chain is variable, and does not affect the load capacity. The more sprockets at the rear wheel (historically 3-6, nowadays 7-12 sprockets), the narrower the chain. Chains are sold according to the number of speeds they are designed to work with, for example, "10 speed chain". Hub gear or single speed bicycles use 1/2" x 1/8" chains, where 1/8" refers to the maximum thickness of a sprocket that can be used with the chain.

Typically chains with parallel shaped links have an even number of links, with each narrow link followed by a broad one. Chains built up with a uniform type of link, narrow at one and broad at the other end, can be made with an odd number of links, which can be an advantage to adapt to a special chainwheel-distance; on the other side such a chain tends to be not so strong.

Roller chains made using ISO standard are sometimes called as isochains.