What Bearing Grade is XTR & Dura Ace?

[Me]

Sorry to ask this again, but I didn't get a definitive answer:

In Dura Ace and XTR hubs, what is the grade of the bearing? 100 grade? 25 grade? Less? More?

cheers

 

[Dave Thompson]

"Me" <[email protected]> wrote in message news:[email protected]...
> Sorry to ask this again, but I didn't get a definitive answer:
>
> In Dura Ace and XTR hubs, what is the grade of the bearing? 100 grade? 25 grade? Less? More?
>
> cheers
>
Dura Ace and XTR use grade 25. There is no better a grade than 25.

 

[DiabloScott]

Dave Thompson "Me" <[email protected]> wrote in message news:[email protected]...

>Dura Ace and XTR use grade 25.
True, Campy does also.


>There is no better a grade than 25.
Nonsense. The ABMA standard grading is the same as the roundness tolerance in millionths of an inch diameter so Grade 25 means +/- .000025 inches. Lower grade number = more precise sizing. ABMA standards include grades from 3 to 1000.
ABMA Ratings Table

 

[Dave Thompson]

"DiabloScott" <[email protected]> wrote in message news:[email protected]...
>
>
> There is no better a grade than 25. Nonsense. The ABMA standard grading is the same as the
> roundness tolerance in millionths of an inch diameter so Grade 25 means +/- 000025 inches. Lower
> grade number = more precise sizing. ABMA standards include grades from 3 to 1000.
> http://www.machiningtech.com/mb.htmlABMA Ratings Table
>
You are correct. Perhaps I should have stated that while Shimano and Campy specify grade 25 bearings
for their best equipment, and that is the best grade one can expect to buy in a bike shop, there are
better grades of bearings available at significantly higher prices.

 

[Qui Si Parla Ca]

Me-<< In Dura Ace and XTR hubs, what is the grade of the bearing? 100 grade? 25 grade? Less? More?
>><BR><BR>

Grade 25....

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Qui Si Parla Ca]

Dave-<< Dura Ace and XTR use grade 25. There is no better a grade than 25.
>><BR><BR>

Sure there is...I know a guy that makes ceramic balls in grade 1 or 2...$8 per ball but they exist.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Jasper Janssen]

On 09 Jul 2003 13:56:04 GMT, [email protected] (Qui si parla Campagnolo) wrote:

>Me-<< In Dura Ace and XTR hubs, what is the grade of the bearing? 100 grade? 25 grade? Less? More?
>>><BR><BR>
>
>Grade 25....

How about the cheaper groups? When do they move to the next best grade (100?), and so on?

Jasper

 

[kh6zv9]

Dave Thompson <[email protected]> wrote:

: "Me" <[email protected]> wrote in message news:[email protected]...
:> Sorry to ask this again, but I didn't get a definitive answer:
:>
:> In Dura Ace and XTR hubs, what is the grade of the bearing? 100 grade? 25 grade? Less? More?
:>
:> cheers
:>
: Dura Ace and XTR use grade 25. There is no better a grade than 25.

I use grade 24 in my rear hubs. Box of 100 cost only about $10.00.

--------------------------------
Bob Masse' [email protected]
--------------------------------

 

[Werehatrack]

On Mon, 7 Jul 2003 16:45:34 -0700, "Dave Thompson" <[email protected]> may have said:

>
>"DiabloScott" <[email protected]> wrote in message
>news:[email protected]...
>>
>>
>> There is no better a grade than 25. Nonsense. The ABMA standard grading is the same as the
>> roundness tolerance in millionths of an inch diameter so Grade 25 means +/- 000025 inches. Lower
>> grade number = more precise sizing. ABMA standards include grades from 3 to 1000.
>> http://www.machiningtech.com/mb.htmlABMA Ratings Table
>>
>You are correct. Perhaps I should have stated that while Shimano and Campy specify grade 25
>bearings for their best equipment, and that is the best grade one can expect to buy in a bike shop,
>there are better grades of bearings available at significantly higher prices.

And diminishing returns for the money. I doubt that you could measure the difference in wheel runout
results with a dial indicator that had sensitivity in half-thousandth gradations.

---
My email address is antispammed; pull WEEDS if replying via e-mail.

Yes, I have a killfile. If I don't respond to something, it's also possible that I'm busy.

 

[A Muzi]

> >> There is no better a grade than 25.

> >"DiabloScott" <[email protected]> wrote in message
> >news:[email protected]...
> >> Nonsense. The ABMA standard grading is the same as the roundness tolerance in millionths of an
> >> inch diameter so Grade 25 means +/- 000025 inches. Lower grade number = more precise sizing.
> >> ABMA standards include grades from 3 to 1000. http://www.machiningtech.com/mb.htmlABMA Ratings
> >> Table

> On Mon, 7 Jul 2003 16:45:34 -0700, "Dave Thompson" <[email protected]> may have said:
> >You are correct. Perhaps I should have stated that while Shimano and
Campy
> >specify grade 25 bearings for their best equipment, and that is the best grade one can expect to
> >buy in a bike shop, there are better grades of bearings available at significantly higher prices.

"Werehatrack" <[email protected]> wrote in message
news:[email protected]...
> And diminishing returns for the money. I doubt that you could measure the difference in wheel
> runout results with a dial indicator that had sensitivity in half-thousandth gradations.

Bearings are graded by uniformity. (Grade 25 certifies no more than +/- .000025 inches _variance_
within that lot) At the highest common commercial grade, 25, you are commensurate with the roundness
and smoothness of the mating parts. There's little if anything to be gained after that in bearing
uniformity
--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971