Ball size for an old Shimano HB-RM50 front hub ?

There's an old nail in my workshop, hoping to turn into a bicycle.

Front hubs are HB-RM50 (commonplace Exage from the early '90s), which you see around everywhere,
but I've never had one apart before. Tried to rebuild it (new cones), but the balls (10x3/16")
won't fit.

Grubbing around in the parts washer tank turned up some skanky old balls that looked like 5/32"
instead. Is this one of those rare hubs that takes odd size balls ? How many ?

Thanks

Had to try three LBS yesterday before I found one that didn't think selling spare cones was
beneath them. 8-(

 

Andy Dingley wrote:
> There's an old nail in my workshop, hoping to turn into a bicycle.
>
> Front hubs are HB-RM50 (commonplace Exage from the early '90s), which you see around everywhere,
> but I've never had one apart before. Tried to rebuild it (new cones), but the balls (10x3/16")
> won't fit.
>
> Grubbing around in the parts washer tank turned up some skanky old balls that looked like 5/32"
> instead. Is this one of those rare hubs that takes odd size balls ? How many ?

I've never known a Shimano front hub to take anything other than 10
3/16" balls per side. I suspect you have incorrect cones if they don't fit.

> Had to try three LBS yesterday before I found one that didn't think selling spare cones was
> beneath them. 8-(

Selling spare cones is an asolute nightmare for shops. There are way too many variations. You need
the correct thread diameter and pitch, the right depth, the right curvature of the race, and the
right outside diameter to fit the hub dustcaps.

Add to this the fact that most of the hubs people want cones for are older models, no longer in
production, often by defunct manufacturers...

It can take an unreasonable amount of research time to locate a match, then the part may or may not
be available.

To top it off, you can't generally charge enough for a cone to cover your labor costs in identifying
and locating it withoug looking like a pirate.

This is an unfortunate situation, but you shouldn't blame the retailers for it.

Sheldon "Can Of Worms" Brown +--------------------------------------------------------+
| Education consists mainly in what we have unlearned. | --Mark Twain |
+--------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
shipped Worldwide http://captainbike.com http://sheldonbrown.com

 

Sheldon Brown <[email protected]> wrote in news:[email protected]:

> Andy Dingley wrote:
>> There's an old nail in my workshop, hoping to turn into a bicycle.
>>
>> Front hubs are HB-RM50 (commonplace Exage from the early '90s), which you see around everywhere,
>> but I've never had one apart before. Tried to rebuild it (new cones), but the balls (10x3/16")
>> won't fit.
>>
>> Grubbing around in the parts washer tank turned up some skanky old balls that looked like 5/32"
>> instead. Is this one of those rare hubs that takes odd size balls ? How many ?
>
> I've never known a Shimano front hub to take anything other than 10
> 3/16" balls per side. I suspect you have incorrect cones if they don't fit.
>
>> Had to try three LBS yesterday before I found one that didn't think selling spare cones was
>> beneath them. 8-(
>
> Selling spare cones is an asolute nightmare for shops. There are way too many variations. You need
> the correct thread diameter and pitch, the right depth, the right curvature of the race, and the
> right outside diameter to fit the hub dustcaps.
>
> Add to this the fact that most of the hubs people want cones for are older models, no longer in
> production, often by defunct manufacturers...
>
> It can take an unreasonable amount of research time to locate a match, then the part may or may
> not be available.
>
> To top it off, you can't generally charge enough for a cone to cover your labor costs in
> identifying and locating it withoug looking like a pirate.
>
> This is an unfortunate situation, but you shouldn't blame the retailers for it.
>
> Sheldon "Can Of Worms" Brown +--------------------------------------------------------+
>| Education consists mainly in what we have unlearned. | --Mark Twain |
> +--------------------------------------------------------+ Harris Cyclery, West Newton,
> Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
> shipped Worldwide http://captainbike.com http://sheldonbrown.com

Andy, next time let your mouse do the walking:

http://www.loosescrews.com/index.cgi?d=single&c=Hub&sc=Cones&tc=Shimano%
20Front&item_id=SH-2310400&id=150773110695

This is where I found mine. I also need to replace a cone in an older rear Exage hub (FH-HG50 drive-
side part #Y2200851). Loosescrews.com doesn't have them. Do you know where I could find this? Would
Shimano tech support hook me up? TIA,
- Boyd S.

 

On Sun, 20 Apr 2003 20:38:30 GMT, Boyd Speerschneider <[email protected]> wrote:

>Andy, next time let your mouse do the walking:
>
>http://www.loosescrews.com

My mouse can't swim though - I'm in the UK. I could probably have got them from Cycle Surgery in
London, who are usually good for awkward little bits

The ball problem turns out to be a mis-labelled packet of balls. When I put the vernier on them
they're 7/32 - no wonder they won't fit ! Do I _look_ like a Campag-riding leg-shaver ?

The other weird thing was the near-total lack of hybrid commuter tyres. I wanted a pair of 26" Conti
Top Turings (old style, not 2000) yet no-one had anything vaguely like that - centre rib and as big
a side chunk as possible. A pair of Specialized Crossroads (and all the other bits) will thus be on
their way from the ever-reliable Edinburgh Bicycle.

 

"Andy Dingley" <[email protected]> wrote in message
news:[email protected]...
> There's an old nail in my workshop, hoping to turn into a bicycle.
>
> Front hubs are HB-RM50 (commonplace Exage from the early '90s), which you see around everywhere,
> but I've never had one apart before. Tried to rebuild it (new cones), but the balls (10x3/16")
> won't fit.
>
> Grubbing around in the parts washer tank turned up some skanky old balls that looked like 5/32"
> instead. Is this one of those rare hubs that takes odd size balls ? How many ? Had to try three
> LBS yesterday before I found one that didn't think selling spare cones was beneath them. 8-(

That hub uses 10x10 3/16" balls.

Did you remove the dust caps? That lets you clean it thoroughly and lets you see the cups clearly.
If you are unsure of a bearing size (there is no question here) you can fit the balls dry and watch
the assembly as you turn the axle. Having one ball out of place would lead you to think you had
chosen the wrong size ball.

Regarding your Exage front, dozens of axle sets interchange with this standard simple design. Should
be easy to find replacement axles/cones.

One problem is that this entire series of Shimano hub is notoriously difficult to remove and
reinstall the dust caps. They are prone to denting on removal but can be pressed back into shape by
sliding them over a socket with a freewheel or cassette tool.

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971

 

On Sun, 20 Apr 2003 18:53:01 -0500, "A Muzi" <[email protected]> wrote:

>Did you remove the dust caps?

No. This is an old nail of a bike - it's not worth the trouble.

I've also seen several reports of trouble getting these out without damage, and I imagine I've no
hope of ever seeing spares.

Thanks to those who've commented.

 

"Andy Dingley" <[email protected]> wrote:

> My mouse can't swim though - I'm in the UK. I could probably have got them from Cycle Surgery in
> London, who are usually good for awkward little bits

If you're still in the Bristol area, try AVC in Bath. They've produced Shimano cones for me from
stock on a couple of occasions.

SJS list a wide range of Shimano cones - useful for reference, even if you don't want to pay their
inflated prices and postage charge.

http://www.sjscycles.com/store/cat422.htm

> The other weird thing was the near-total lack of hybrid commuter tyres. I wanted a pair of 26"
> Conti Top Turings (old style, not 2000) yet no-one had anything vaguely like that - centre rib and
> as big a side chunk as possible.

The Conti Town & Country is like a fatter, old-style Top Touring in 26 x
1.9 or 2.1".

James Thomson

 

The Good Captain<< I've never known a Shimano front hub to take anything other than 10
3/16" balls per side. I suspect you have incorrect cones if they don't fit.

DuraAce uses 11-3/16 per side for the front....

<< Selling spare cones is an asolute nightmare for shops. There are way too many variations. You
need the correct thread diameter and pitch, the right depth, the right curvature of the race, and
the right outside diameter to fit the hub dustcaps.

Ya can say that twice, twice....

I'll point at shimano for this, even having different cones left to right of some rears...

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(4)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

On Sun, 20 Apr 2003 23:06:35 +0100, Andy Dingley <[email protected]> wrote:

>
>The other weird thing was the near-total lack of hybrid commuter tyres. I wanted a pair of 26"
>Conti Top Turings (old style, not 2000) yet no-one had anything vaguely like that - centre rib and
>as big a side chunk as possible. A pair of Specialized Crossroads (and all the other bits) will
>thus be on their way from the ever-reliable Edinburgh Bicycle.

Did you look at the Conti Travel Contact?

http://www.conti-tyres.co.uk/conticycle/tyreinformation/Travel%20Contact.htm

The profile is rounder than the Crossroads.

 

On 21 Apr 2003 12:51:57 GMT, [email protected] (Qui si parla Campagnolo) wrote:

>The Good Captain<< I've never known a Shimano front hub to take anything other than 10
>3/16" balls per side. I suspect you have incorrect cones if they don't fit.
>
>DuraAce uses 11-3/16 per side for the front....

Glad to hear that. After reading Sheldon's response I started to worry. I've been dropping 11 into
mine for years.

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