question about bearing speed ratings
g'day.
i just bought a spare final drive bearing for my r11gs. i was able to obtain the right size, but without the 'C3' rating for rpm.
as i understand it, high-speed rated bearings have a little more space between race and balls, i assume to allow for heating at speed. can anyone add to this?
the bearing i bought is NTN, should be good. though not C3, it is rated to 6300rpm, and my maths tells me that at 120km/h, my rear wheel is turning at about 1000rpm. according to the following maths:
c (circumference) = 2 x pi x r,
where r = .33m,
c = 2.1m
right, why should C3 speed rating be required at all when there is such a wide margin (6300 - 1000 = 5300) between real-world rotation speed and the rated tolerance?
i have not yet fitted the bearing. can anyone suggest why i would not? any input welcome and appreciated.
cheers,
andy.
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