|Servicing hub... is there different bearing quality ?||PeterRider|
Feb 18, 2003 1:38 PM
|My front Shimano 600 hub feels like it could use some servicing... I'll take the occasion for changing the bearings. What bearings do you recommend ? I want of course something that rolls as smooth as possible.
Just hope I won't discover that it's a hub with integrated bearings and I can't change them...
Feb 18, 2003 3:21 PM
|A grade 25 bearing is .00025 inches out of round. Campy and Dura-Ace bearings are grade 25.
Generic bearings are probably grade 300. They are .003 inches out of round.
|Campy used to be grade 10+||Kerry|
Feb 18, 2003 4:18 PM
|They used to select among lots of grade 10 bearings to get the equivalent of grade 1. Do you have a reference to the grade 25 spec. for Campy?|
|..but mine go to 11. nm||Spunout|
Feb 19, 2003 4:40 AM
Feb 19, 2003 7:17 PM
|Cause it's better than 10! nm.||aeon|
Feb 19, 2003 10:57 PM
|Time to rent 'Spinal Tap' for my next rollerfest! ;-) nm||Spunout|
Feb 20, 2003 4:52 AM
|Gawd...there are some sick, but great, folks on here!(nm)||merckx56|
Feb 20, 2003 11:13 AM
|Here's what I found............||davet|
Feb 19, 2003 4:45 AM
|"Following is a description of the different grades of ball bearings. The grade specifies the sphericity of the balls in millionths of an inch. Thus, grade 25 are round to 25/10^6, while grade 1000 are good to 1/1000 (i.e. not all that round, but probably good enough for our uses).
Grade 25: the highest quality normally available, aka
"Campagnolo quality": hardened all the way through, best alloys, coatings, roundness, and durability."
Evidently when bearings are "graded", it not only refers to the roundness, but to the actual "quality" of the bearing itself. The cost difference between a hubfull of grade 25 bearings and grade 300 bearings is only a couple of bucks, nothing in the greater scheme of things. It would seem to me that trying to save money in this arena would be a prime case of being 'penny wise and pound foolish'.
|QBC catalogue (nm)||Spoke Wrench|
Feb 19, 2003 3:43 PM
|loose screws urls||4bykn|
Feb 21, 2003 2:50 PM
|Hub Service and bearings||Calvin|
Feb 20, 2003 6:35 AM
|As stated above, the grade refers to the tolerance of the balls. Keep in mind the cup and cone are not ground as accurately as the balls. fn the ball bearings are shot, it is likely the cone and maybe even the cup are also bad. Be sure to inspect the cone and cup for pitting and wear. |
Below is an image of high quality cone of a well known brand, seen with the might QX3 microscope.