DINGGUANGHE-CUP 8PCS Caged Ball Bearings OD 31mm Rear Bike Wheel Hub Headset Crankshaft Pivot Retainer Steel 9 Balls Bearings Accessories

Description

• Caged Bike ball bearing Description: replace parts (crankshaft bearing, headsets, hubs).
• The diameter are measured inside and outside (it's an approximate value in mm).
• Item:31 mm, 9 balls (rear hub)
• Outside diameter: 31 mm
• Number of balls: 9

Tech Brief Bearing seal cross-section
We manufacture and use Angular Contact Bearings (ACB) for our headsets.
The manufacturing process begins with the rough shape of the bearing races being machined from high quality steel. Both the inside and outside of each race is then precision stone-ground to reach its final shape.
Computer controlled grinding equipment is used to grind each race to exact tolerances.
The races are then assembled with the balls to create the finished bearing.

All about Headset Bearings:
1. How many different types of bearings are used in the modern day headset?
Answer: There are at least 6 different kinds of bearings used in the bicycle headset. They include; radial bearings, thrust bearings and angular contact bearings. These three types of bearings all use ball bearings. The second category of bearings is the roller bearings which include the standard roller bearing and the tapered roller bearing. Both of these use cylindrical rollers.
2. There are many different types of bearings. Which one is best for the bicycle headset and why?
FAQ
1. Why do the bearings I receive have shaking?
The clearance of the bearing is related to the play.
The default is the standard C0 clearance, which is usually 3-18um.
The corresponding principle is shown in the figure below.
If you don't need to shake, please choose C2 small clearance bearing,
If you have any questions, please contact us before purchasing.
2. What is the accuracy of ABEC-1?
ABEC is the American ANSI standard.
The corresponding German DIN standard and international ISO standard are as follows:

Shipping and Returns

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• All customers are entitled to a return window of 14 days, starting from the date of delivery of the product(s).
• Customers are advised to read our return policy for details of the return process, eligibility, refunds as well as cancellations or exchanges.
• In case of any issues or concerns about Shipping or Returns, please contact us and we will be happy to help.