The secondary drive section of a motorcycle consists of a chain and sprocket, which are made to be changeable so as to replace worn out parts and to alter the final drive ratio of the bike.
Chains and sprockets are sized by the pitch which could be the distance from roller to roller on a chain or from point to point on a sprocket.
A chain and sprocket must have the same pitch for them to be compatible.
Chains and sprockets also vary in width, with the varying factors being the machine’s mass and power. Larger chains and sprockets, which are usually wider, are meant for more powerful machines that can bear heavier loads.
A larger machine produces more power and thus would require a wider chain and sprocket. Common sizes for sports bikes are 520, usually an aftermarket choice for the machines, 525, the most common 600cc pitch and 530, usually stocked on a 1000cc machine.
The 520 is the best choice if you are looking to replace your chain and sprocket. Its options are vast and it is highly likely there are options for your bike. It has many advantages over 600cc through 1000cc machines, inclusive of it having more gear options for any machine, its use reducing unsprung weight (nearly 8lbs) and the reduced weight can slightly improve the bike’s performance.
Its disadvantages include that even with stock gearing it may increase fuel mileage and it has a short life expectancy on higher displacement machines.
Gearing options include gearing ‘shorter' and gearing ‘taller.' In gearing shorter, the gear ratio is higher, and the engine will turn higher rpms to acquire the same speed as a taller geared machine. Taller-geared machines have a lower gear ratio with the engine turning fewer rpm’s to acquire the same speed as a shorter machine.
Shorter gearing acquires lower top-speed, increases mechanical torque thus faster acceleration shortens the usable speed range for gears and can increase the bike's natural anti-squat ability. Taller gearing acquires a higher top speed, lowers mechanical torque thereby lessening acceleration, increases any gear's usable speed range and may decrease the bike's natural squat ability.
Gearing choice also depends on the size of your current gear and tires as well as your current needs and the bike's.
How to Calculate Secondary Drive Ratio:
Number of teeth on rear sprocket/Number of teeth on the front sprocket.
This would provide you with a ratio of X: 1. The higher the ratio, the shorter the gearing will be. A tall ratio would be 2.5:1 while a shorter one would be 3.5:1.
Shift points are also affected by drive ratio. A shorter drive ratio causes increased shifting of the bike, with less speed range between gears. A taller drive ratio has a higher speed range between and requires less shifting.
Tire size also affects gearing. This is because overall circumferences of the tires vary from manufacturer, even within the same tire denomination. Tires with a smaller circumference gear shorter than tires with larger circumferences. This affects gearing and therefore the motorcycle’s overall performance.
Anti-squat properties are minimal. Normally this is considered during aggressive gearing changes such as a 600cc machine geared for stunting where the rear sprocket exceeds 52 teeth. If you use both front and rear sprockets to achieve your desired ratio, then you do not need to consider this property. However, if you gear taller, you need to realize that this reduces anti squat and the bike's handing on corner exits can be affected. Aggressive gearing, however, does not affect the bike's handling performance.
What Gearing do you Need?
In my personal opinion, I stay with stock gearing. The only way I would get a 520 conversion is if I were riding in the city ONLY. With very little highway or freeway riding. The choice is yours on which type of riding you plan on doing.
Regarding gearing the machine, the accepted rule is to do so in a way where the bike gets to nearly redline on the highest gear on the longest straight. This, however, would not be practical in most cases since most tracks do not have a long enough straight that you would get to 6th gear. It is more advisable to gear to 5th, which could mean gearing taller from your current position. Thus gear to the highest gear practical, on the longest straight when you are near redline. Also, consider shift points – you may get stuck mid-turn so change gearing to obtain the best compromise.
Street gearing lays emphasis more on opinion than fact. The most common gear change is the -1 +2, 520 conversion, representing the front and rear sprocket pitches respectively and referencing them to the biker's current sprockets. Once changed, the front sprocket is one tooth smaller than its reference while the rear sprocket is two teeth larger than its reference. This has the bike traveling with higher average rpms at any speed and also increases acceleration while lessening fuel mileage.
Master Link Type
Chains could come with a clip type master link. This is the easiest and master link and also the weakest link in the chain. It could also, alternatively, come with a riveted master link which is superior and is the same as other links in the chain.
Clip style links should not be installed on a bike with over 600cc's in displacement. Chains also come with rings that go in between the plates and the chain. They are inclusive of O-Ring, X-Ring, and W-Ring with each letter describing its respective ring's shape.
Each ring is designed to keep dirt and debris from getting into the bike's system while at the same time preventing the spilling of the chain roller's lubricant. O-Rings, though the cheapest, have the lowest form of protection and life expectancy.
X-Rings provide better performance and life expectancy at a modest price. W-Rings are the most expensive and should have the longest chain life. However, differences in the performance of X and W-Rings are slight.
For purchase purposes, any major brand will provide quality spare parts for use in your motorcycle. It is advisable to avoid cheap sales online from sellers with little history. This is because you are unsure of how dependable their parts are and could risk losses as well as your motorcycle’s performance. If you are doing other upgrades to your motorcycle, check out our Products Page. It includes rearview motorcycle cameras, passenger peg blinkers, and more!
It is my hope this guide answers all your questions and helps you towards making better chain and sprocket choices.