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SUPERSPROX STEEL REAR SPROCKET RFE-990:40-BLK
Product Extra Information
|Inner diameter (ID)||125|
|Pitch circle diameter (PCD)||150|
Select option below to choose diffent teeth and color
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Each order from 220PLN value of goods, indlude free shipping inside Poland. If order total is less then 220PLN, shipping cost will be calculated.
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Available in colors
Why Supersprox Racing Steel
- CAD Designed and CNC Laser cut to ensure an exact fit.
- One of the lightest all steel sprockets on the market.
- The steel theet last 3 times longer than aluminum.
- Developed on the race track to give longer system life and high performance.
- Include our exlusive 2x zink for anti corrotion and black finish.
- Special tooth design increases chain contact and significantly extends the sprocket life.
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Out of Stock
Items rated with 3-5 stars are the most popular and highest quality.
Items rated with 1-2 stars are usually new or rare products.
Unused items in saleable condition purchased from our eShop may be returned within 30 days of the purchase date for a credit to the card on which they were originally purchased. Returned goods will only be accepted with prior authorization. For more detailed return policy click here.
I received a damaged product
If the sprocket you purchased is damaged please make images and send to us by email and one of our representative will connect with you within 48h.
Exchange of the sprocket is possible only if the sprocket is not used and purchased from our eshop directly. Return sprocket will be fully refunded (excluding shipping) and a new order for the exchange sprocket has to be placed on our eshop.
All sprockets are guaranteed against defects in material and workmanship. Because we cannot control the application of our sprockets, buyers assume risks for any and all damage caused to themselves and others due to any failures. No warranty, expressed or implied, is made. Sprockets are designed and manufactured to be used specifically on the models listed in our catalog. Clearances must be checked before ordering different size sprockets than originally came on the machine. Chains are guaranteed in accordance with the manufacturer’s own terms of warranty. All products leave our warehouses in good condition, therefore if you receive an item that is not in good condition it should be immediately reported.
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GEAR RATIO EXPLAINED
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, devide 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 performace.
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.
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 increase the number of teeth on the front 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. This will help understanding in relation to 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 moving that backwards or forwards. 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 15.875mm per link to be exact). But 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 to correctly adjust the chain, 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 and it is neccasary to remove even numbers of links (2, 4, 6, 8 etc).