How many bearings fit insde a rear hub?

J.L

Hello, I'm new to this news group.

I was wondering how many bearings go inside a rear hub?

I had taken apart the hub to replace a bent axle. My parts tray
has a whole bunch of bearings in it, from various assemblies. No I can't
figure out how many bearings go into the hub!

This is a standard mountain bike hub made by joytech. Nothing fancy, just
(i guess) a cheap 8 speed hub.

Do I leave no room? lots of room? I've never been able to figure out how
many bearings need to go in. I saw a diagram once, where it was six on one
side and seven on the other, but it seems that the raceway can fit nine!

Any help would be great.

Thanks.
Jason

Dan Daniel

On Sat, 17 Apr 2004 16:53:15 GMT, "J.L" <J@this.is.not.a.real.address>
wrote:

>
>Hello, I'm new to this news group.
>
>I was wondering how many bearings go inside a rear hub?
>
>I had taken apart the hub to replace a bent axle. My parts tray
>has a whole bunch of bearings in it, from various assemblies. No I can't
>figure out how many bearings go into the hub!
>
>This is a standard mountain bike hub made by joytech. Nothing fancy, just
>(i guess) a cheap 8 speed hub.
>
>Do I leave no room? lots of room? I've never been able to figure out how
>many bearings need to go in. I saw a diagram once, where it was six on one
>side and seven on the other, but it seems that the raceway can fit nine!
>
>Any help would be great.
>
>Thanks.
>Jason

Standard Shimano rear hubs will have 9 bearings, 1/4", on each side.
There should be room, but very little. Try what seems to fit, assemble
and see if it rolls smooth and the lock nuts are in about the same
position on both sides (assuming that you left one lock nut and cone
in position on disassembly).

Always best to count on first exposure to a hub! Clean the work area
every now and then?

Zoot Katz

Sat, 17 Apr 2004 16:53:15 GMT,
<pan.2004.04.17.16.53.29.587736@this.is.not.a.real.address>,
"J.L" <J@this.is.not.a.real.address> wrote:

>I was wondering how many bearings go inside a rear hub?

A handy mnemonic is TEN

Ten in the front hub.
Eleven in the BB
Nine in the rear hub.
--
zk

David Kerber

In article <pan.2004.04.17.16.53.29.587736@this.is.not.a.real.address>,
J@this.is.not.a.real.address says...
>
> Hello, I'm new to this news group.
>
> I was wondering how many bearings go inside a rear hub?
>
> I had taken apart the hub to replace a bent axle. My parts tray
> has a whole bunch of bearings in it, from various assemblies. No I can't
> figure out how many bearings go into the hub!
>
> This is a standard mountain bike hub made by joytech. Nothing fancy, just
> (i guess) a cheap 8 speed hub.
>
> Do I leave no room? lots of room? I've never been able to figure out how
> many bearings need to go in. I saw a diagram once, where it was six on one
> side and seven on the other, but it seems that the raceway can fit nine!
>
> Any help would be great.

Nine is a common, but not universal standard. There should be very
little extra space between the bearings when they are in place in the
race.


--
Dave Kerber
Fight spam: remove the ns_ from the return address before replying!

REAL programmers write self-modifying code.

Jacobe Hazzard

J.L wrote:
> Hello, I'm new to this news group.
>
> I was wondering how many bearings go inside a rear hub?
>
> I had taken apart the hub to replace a bent axle. My parts tray
> has a whole bunch of bearings in it, from various assemblies. No I can't
> figure out how many bearings go into the hub!
>
> This is a standard mountain bike hub made by joytech. Nothing fancy,
> just (i guess) a cheap 8 speed hub.
>
> Do I leave no room? lots of room? I've never been able to figure out how
> many bearings need to go in. I saw a diagram once, where it was six on
> one side and seven on the other, but it seems that the raceway can fit
> nine!
>
> Any help would be great.
>
> Thanks.
> Jason

Something the other posters didn't mention is that you shouldn't re-use
potentially mis-matched bearings. Small differences in size between
bearings from different lots will render the smaller bearings quite
useless, and accelerate wear on the bearing assembly. Repack your hub with
as many new, matching bearings as you can fit.

Mike Kruger

"Jacobe Hazzard" <nospamfakeaddress@mousepotato.com> wrote in message
news:SXigc.1961

> Something the other posters didn't mention is that you shouldn't re-use
> potentially mis-matched bearings. Small differences in size between
> bearings from different lots will render the smaller bearings quite
> useless, and accelerate wear on the bearing assembly. Repack your hub with
> as many new, matching bearings as you can fit.
>
Under the circumstances, the best thing to do is take the wheel into a bike
shop and say "I need a new set of bearings". They will hand you some, they
will be the right number and size, and they won't cost much - certainly a
lot less than the cost of making a mistake.

David L. Johnson

On Sat, 17 Apr 2004 23:19:49 +0000, Mike Kruger wrote:

> "Jacobe Hazzard" <nospamfakeaddress@mousepotato.com> wrote in message
> news:SXigc.1961

> Under the circumstances, the best thing to do is take the wheel into a bike
> shop and say "I need a new set of bearings".

Why? You presume that the shop people know some secret knowledge. But
the vast majority of standard hubs take 9 1/4" bearings on each side.
Some high-zoot hubs will be different, but this does not seem to be the
case. Figuring out how many fit is not rocket science. Don't cram so
many in that they bind, but other than that as many as will fit is the
answer.

--

David L. Johnson

__o | Accept risk. Accept responsibility. Put a lawyer out of
_`\(,_ | business.
(_)/ (_) |

Mike Kruger

"David L. Johnson" <david.johnson@lehigh.edu> wrote in message
newsan.2004.04.18.04.22.17.153678@lehigh.edu...
> On Sat, 17 Apr 2004 23:19:49 +0000, Mike Kruger wrote:
>
> > "Jacobe Hazzard" <nospamfakeaddress@mousepotato.com> wrote in message
> > news:SXigc.1961
>
> > Under the circumstances, the best thing to do is take the wheel into a
bike
> > shop and say "I need a new set of bearings".
>
> Why? You presume that the shop people know some secret knowledge. But
> the vast majority of standard hubs take 9 1/4" bearings on each side.
> Some high-zoot hubs will be different, but this does not seem to be the
> case. Figuring out how many fit is not rocket science. Don't cram so
> many in that they bind, but other than that as many as will fit is the
> answer.
>
The original post says:

"... how many bearings go inside a rear hub?
.... My parts tray
has a whole bunch of bearings in it, from various assemblies. ...
I saw a diagram once, where it was six on one
side and seven on the other, but it seems that the raceway can fit nine!"

Possible trouble arises if you use the wrong number, the wrong size, or a
mix of sizes.
Old or flattened bearings are a possibility here, since he "had taken apart
the hub to replace a bent axle".

I'm likely being conservative, but if I was replacing an axle bent from
stress, I'd replace the bearings as a matter of course, and if I'd spilled a
bunch out on the floor -- something I've never done, of course -- I'd
recheck the number. Asking on a newsgroup is fine, but we can't see the hub.

John Everett

On Sat, 17 Apr 2004 23:19:49 GMT, "Mike Kruger"
<MikeKr@mouse-potato.com> wrote:

>"Jacobe Hazzard" <nospamfakeaddress@mousepotato.com> wrote in message
>news:SXigc.1961
>
>> Something the other posters didn't mention is that you shouldn't re-use
>> potentially mis-matched bearings. Small differences in size between
>> bearings from different lots will render the smaller bearings quite
>> useless, and accelerate wear on the bearing assembly. Repack your hub with
>> as many new, matching bearings as you can fit.
>>
>Under the circumstances, the best thing to do is take the wheel into a bike
>shop and say "I need a new set of bearings". They will hand you some, they
>will be the right number and size, and they won't cost much - certainly a
>lot less than the cost of making a mistake.

Two potential mistakes in this suggestion:

1) A bike shop will probably charge you as much for 18 (or so) balls
as a bearing specialty shop would charge you for 100.

2) Always have more balls in hand than you need. It's really
frustrating when you fumble one and it rolls into an alternate
universe. Bearing balls are one of the few physical objects that do
this with some regularity.


jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3