Always Insist on Genuine
Chain and Sprocket Kits
Quality of Genuine Chain & Sprockets
Chain
No other kind of chain is called on to perform in as harsh an environments as a motorcycle chain. There are two basic types of motorcycle chains: standard (or open) chain and sealed chain. Standard chain is normally found on smalldisplacement, general-purpose motorcycles, while sealed chain is used on high-speed touring bikes and other highload, large-displacementmodels. Both types have a similar construction, in which inner links comprising inner plates, bushings, and rollers are joined to outer links comprising outer plates and pins. Sealed chain incorporates O-rings (or X-rings) to seal grease between the bushings, making for superior resistance to wear. The difference between a good chain and a bad chain can be seen most clearly in the degree of stretching caused by wear and the resistance to fatigue. Superior chains are characterized by the following aspects:
• Strong resistance to wear
• Strong resistance to fatigue
• Ability to withstand shock and tensile force
• Joints which remain flexible
Sprockets
Sprockets come in two types: the drive sprocket, which is mounted on the engine, and the driven sprocket, which is affixed to the rear wheel. These two types of sprockets are linked via the chain. Like the chain, the sprockets are continuously subjected to a driving force as well as the rapidly fluctuating impact caused by constant acceleration and deceleration. They must therefore be capable of withstanding shock and wear, particularly in the teeth area. For this reason, we have used data accumulated over many years to develop Genuine Yamaha sprockets, which offer optimum quality in terms of design, materials, and machining. With regard to heat treating, for example, Yamaha uses its own high-frequency quenching process to produce sprockets. Because of this process, Yamaha sprockets have an ideal hardness range. Surfaces which are in constant contact with the chain are hardened to the maximum and toward the sprocket’s centre the hardness gradually decreases for greater toughness. Quenching is the single most important process in determining the sprocket’s durability.Ideal Matching
When a sealed chain is used in combination with sprockets made of soft materials that have not been properly heat treated, the sprockets will wear faster than the chain, with the deformation of the sprockets’ teeth causing damage to the chain that will speed the stretching process. Conversely, if high-quality Genuine Yamaha sprockets are used with low-grade chain that is easily worn the sprockets will not be effective. What’s more, the imbalance between the chain and the sprockets will dissipate engine power and increase noise.Because of this extremely close relation-ship between chain and sprockets, using improperly matched, non-genuine parts could have an adverse impact on performance as well as safety. You should thus always insist on Genuine Yamaha chains and sprockets and replace them together.
