Freewheel hub thread spec - Same for Campy and Shimano?

[Steve Freides]

Can you thread a Shimano freewheel onto a Campy freewheel hub and
vice-versa? I know the cog-to-cog spacing is different, but didn't know
if the threading on the hub itself or the diameter is different between
the two freewheels.

Thanks in advance. I'm mostly curious as it concerns old stuff I might
buy to use in my fixed-gear bike, e.g., can I buy an old Campy hub and
thread on the cogs I've been using on my Shimano hubs?

-S-

[Mark Atanowicz]

In article <35EDC0...@idt.net>
Steve Freides <sj...@idt.net> writes:

> Can you thread a Shimano freewheel onto a Campy freewheel hub and
> vice-versa? I know the cog-to-cog spacing is different, but didn't know
> if the threading on the hub itself or the diameter is different between
> the two freewheels.

Threading is the same, and AFAIK, so is the spacing (5.0 mm cog to
cog).

Mark Atanowicz

[Sheldon Brown]

[mosted & pailed]

Steve Freides wrote:
>
> Can you thread a Shimano freewheel onto a Campy freewheel hub and
> vice-versa? I know the cog-to-cog spacing is different, but didn't know
> if the threading on the hub itself or the diameter is different between
> the two freewheels.
>

> Thanks in advance. I'm mostly curious as it concerns old stuff I might
> buy to use in my fixed-gear bike, e.g., can I buy an old Campy hub and
> thread on the cogs I've been using on my Shimano hubs?

Yes, the threads are basically the same. There used to be a slight difference
between Italian and British, but not enough to cause a problem. When the ISO
adopted the British thread pattern, Italian faded away.

Older Campagnolo hubs would have the word "England" or "Italy" stamped into
the shell at the end of the freewheel threads, but you can ignore this
distinction...it was only a problem if you kept switching back and forth
between Italian and standard freewheels on the same hub. More details on this
can be found in my Bicycle Glossary at:
http://www.sheldonbrown.com/gloss_i-l.html#italian

There was also a French size, which is definitely _not_ interchangeable, but
only a small percentage of French imports to the U.S. market used the obsolete
French thread, so even most French-made hubs and freewheels have standard threads.

Sheldon "Sometimes There Is Progress" Brown
Newtonville, Massachusetts
+-----------------------------------+
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| restaurant is like a peeing |
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+-----------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-1040 FAX 617-244-1041
http://www.sheldonbrown.com/harris
Hard-to-find parts shipped Worldwide

[Mark McMaster]

Steve Freides wrote:
>
> Can you thread a Shimano freewheel onto a Campy freewheel hub and
> vice-versa? I know the cog-to-cog spacing is different, but didn't know
> if the threading on the hub itself or the diameter is different between
> the two freewheels.
>
> Thanks in advance. I'm mostly curious as it concerns old stuff I might
> buy to use in my fixed-gear bike, e.g., can I buy an old Campy hub and
> thread on the cogs I've been using on my Shimano hubs?

Probably, but it depends on which threading standards are used for the
hub and freewheel. The 4 most common threading standards used for
freewheels are:

ISO: 1.375" x 24tpi
English: 1.370" x 24tpi
French: 34.7mm x 1mm
Italian: 35mm x 24tpi
(Note: ISO is halfway between English and Italian, so can be
interchanged with either one).

Starting from the freewheel: Practically all Shimano freehubs use
English threads. Campy hubs came in either English, Italian or French
threading, but English and Italian are the most common. Fortunately,
Campy marks the thread dimensions on the freehub. If it is English
threading, you'll have no problem. If it is Italian threading, you will
be able to use the freewheel, but since the Italian threads are slightly
different diameter, the threads on the hub will be slightly damaged.
Normally this is not a problem unless you exchange freewheels often, or
are a particularly large or strong rider.

Mark McMaster
MMc...@ix.netcom.com

[Steve Freides]

As usual, a thorough and complete technical explanation. Thank you.

-S-

Mark McMaster wrote:
>
> Steve Freides wrote:
> >
> > Can you thread a Shimano freewheel onto a Campy freewheel hub and
> > vice-versa? I know the cog-to-cog spacing is different, but didn't know
> > if the threading on the hub itself or the diameter is different between
> > the two freewheels.
> >
> > Thanks in advance. I'm mostly curious as it concerns old stuff I might
> > buy to use in my fixed-gear bike, e.g., can I buy an old Campy hub and
> > thread on the cogs I've been using on my Shimano hubs?
>
> Probably, but it depends on which threading standards are used for the
> hub and freewheel. The 4 most common threading standards used for
> freewheels are:
>
> ISO: 1.375" x 24tpi
> English: 1.370" x 24tpi
> French: 34.7mm x 1mm
> Italian: 35mm x 24tpi
> (Note: ISO is halfway between English and Italian, so can be
> interchanged with either one).

-snip-