Sprockets Specifications:
Brand: Supersprox StealthPitch: 520Front Sprocket (teeth): 14
Rear Sprocket (teeth): 50
Front Sprocket Material: SCM-435 (18HGT) carbon free steel and carbon impregnated ultra hard surfaceRear Sprocket Material: Triple Zink plated steel teeth ring, Forged stainless steel rivets, 7075-T651 Aluminum core center, Hard anodized color. European patent #03792104.6, US patent #7,481,729 B2
Front Sprocket Color: Black with optional Orange and Blue inserts includedRear Sprocket Color: Black Steel Teeth / Orange Aluminum Center
Made in: Poland/Czech Republic
Call for Optional Gear Ratios
Call for further information or optional ratio requests;
RPE Motorcycle RPEcycle.
10725 Beverly Bl, Whittier, CA 90601
hours: M-F 10-6 Pacific Std. Time
Will Calls and Installation appointments are welcome!
Also available from RPE Motorcycle...
Pro Chain Tool Installation Kit @ $79.95 when purchased with a chain & sprockets kit!
CHAIN TOOL IS AN OPTIONAL ACCESSORY (NOT included with listed chain and sprockets price)
Clip Type Master Link @ $10.95 when purchased with a chain & sprockets kit!CLIP TYPE MASTER LINK IS AN OPTIONAL ACCESSORY (NOT included with listed chain and sprockets price)
CHAIN PITCH ; Chain pitch for full size off road motorcycles is always 520 size. 520 is the lightweight but strong off road standard pitch, used on all 125/250/450 MX motorcycles. 525 is 2mm wider than 520, and 530 is 2mm wider than 525. 530 being the widest, is heavier, but has a wider contact area between the sprocket teeth, and the chain rollers, therefore spreading out the wear and lasting longer.525 and 530 are commonly used on larger displacement street bikes. 520 size benefit is lighter weight, less material, and less expensive. 530 size (for BIG street bikes) benefit is longer lasting, but heavier due to more material which is more expensive. 525 splits the difference. All chain manufacturers make every pitch size in standard strength, and high strength models. Higher tensile strength is achieved with larger pin diameters, thicker side plates, and better steel quality, thus more expensive.
OEM RATIO ; Front tooth count vs. rear tooth count (example 50/13 = 3.85:1 ratio). OEM ratio is the manufacturer's calculated "Happy Medium" of off the line low end acceleration and top speed. Reasonable top gear cruising rpm's with the least amount of compromise on low end acceleration or top end speed. Best "all around" ratio for every gear as designed by the manufacturer to optimize available horsepower and transmission gears use. ** Exact length chain will always be supplied with an OEM Ratio kit ordered from RPE Motorcycle.
SHORT TRACK MX - QUICK ACCELERATION gear ratio; Low End Improvement achieved with a smaller front or a larger rear sprocket.
* Typical QA Ratios; -1t front/oem rear = Regular QA , -1t front/+1t rear = more aggressive QA, -1t front/ +2 or more rear = Extreme QA - stunt gearing/drag racing/hill climbing.
* Disadvantage; slower top speed, higher top gear cruising rpm's.
* Chain length will be same as OEM with a -1t front sprocket "QA ratio" is used, but a larger QA rear sprocket order will be supplied with a 120L chain length that will need "cut to length" during the installation process. * Advantage; better short track MX gearing, quicker throttle response, quicker off the line and mid range, quicker 1/4 mile time, low end and mid range torque improvement.
DESERT RACE GEARING gear ratio ; Top End Improvement achieved with a larger front or a smaller rear sprocket. * Advantage; Faster top speed with lower top gear cruising RPM's * Disadvantage; Will be less responsive @ low rpm's and slower off the line in first gear. * Chain length will be same as OEM when a +1t front sprocket is used, but a smaller rear sprocket order will be supplied with a 120L chain length that will need "cut to length" during the installation process.
RPE Motorcycle RPEcycle.
hours: M-F 10-6 Pacific Std. Time
10725 Beverly Bl, Whittier, CA 90601
Gear ratio explained;
The gear ratio, is the ratio of turns made by one gear, compared to the other gear, when the gears are connected by a chain. An example of gear ratio will be with one gear of 10 teeth and the second gear of 20 teeth, giving a ratio of 2 (20/10=2). To calculate the ratio, divide the number of teeth on the rear sprocket, by the number of teeth on the front sprocket and the resulting number is your gear ratio.
Why do you need to know your gear ratio? It might be, that your bike is not performing as you would like and a change in gear ratio might help the performance.
GEAR DOWN. An example of this would be, that the bike is difficult to start in first gear and the clutch needs to be used more than you would like. You have plenty of top end speed, but need more slow speed control. The answer, might be to GEAR DOWN the bike. You can do this by adding more teeth to the rear sprocket or reducing the number of teeth on the front sprocket.
A -1t front is about the same ratio change as a +3t rear sprocket.
GEAR UP. The opposite situation, might be that the bike has lots of power, but is reaching the rev limiter in top gear and you would like to reduce the revolutions at a particular speed. To do this, you would need to GEAR UP the bike. By reducing the number of teeth on the rear sprocket or increasing the number of teeth on the front sprocket. Some bikes have space limitations for front sprockets in the engine case sprocket cavity, and more than +1 tooth larger than the oem original may not have enough clearance.
A +1t front is about the same ratio change as a -3t rear sprocket.
Diameter of gear. Each tooth added or taken away from a sprocket, will reduce the diameter of the sprocket by a given amount. For simplicity, you can think about 5mm change on the diameter, for each additional or reduced tooth. It will help to understand the relation of space requirements for gear ratio changes.
Chain length. The addition of teeth to the sprocket, may require a longer chain or changing the position of the rear wheel, by adjusting the axle back or forwards while maintaining proper chain slack. It will depend on the addition or subtraction of sprocket teeth. This can be calculated by considering the chain pitch. For simplicity, you can think about each chain link requiring 16mm length . Actually, 520, 525, 530 chains require exactly 15.875mm per link (pin). Remember, the chain is going around the rear sprocket and the front sprocket, so the important number would be the change in diameter of the sprocket and not the chain length. An example would be to remove one tooth from the rear sprocket. This would make the chain more loose and need to be correctly adjusted, you would need to move the rear wheel backwards (away from the small sprocket) by 5mm. This movement would compensate for the change in diameter. Due to chain construction, it is not possible to remove only one link (pin), so it is necessary to remove an even numbers of links (2, 4, 6, 8 etc). A 120L chain has 120 pins, and 60 side plates (which have two pins each).
Best practice is to move the axle nearly as far forward as possible, feed the chain around the sprockets, and fold over the excess chain links to be removed. Mark the unnecessary links, and remove them for the best fit before installing the master link.
Removing Chain Links. To remove excess chain links (known as cutting a chain down to size), you can push the both pins out on one side plate with a chain tool,
or.. (a) simply grind the protruding pins until flush with the side plate, (b) put a wedge (chisel edge) between the inner and outer side plate gap, hit it with a hammer, and the side plate will come right off. Now the entire remainder of the unwanted link will slide right out the other side as a complete unit, as well as the unwanted length of chain formerly connected. Easy!