11T Cogs, Hyperglide "C", and other esoterica

[Art Harris]

I'm plan to install a 9-sp cassette with an 11T cog on my wife's bike. I didn't think that was going
to be complicated until I read about Hyperglide "C" systems on Sheldon's "Kah Sept" page. It seems
that a special Hyperglide "C" freehub body (with splines that don't extend to the end of the body)
are required to accomodate an 11T cog. Otherwise, a 1 mm spacer has to be added.

Then, I looked at Shimano's site, and it appears that the splines on all their modern freehubs don't
extend to the end of the FH body.

Then, in the case of the Sora Freehub, Shimano implies that an 11T cog MUST be used.

Questions:

1) Can a 105 or Ultegra freehub accept either an 11T or 12T outer cog without a spacer (assuming
that the appropriate lockring is used?

2) Why does the Sora freehub require an 11T? Will it not accept a 12T?

Thanks, Art "hyper confused" Harris

 

[Zog The Undenia]

Art Harris wrote:

> 1) Can a 105 or Ultegra freehub accept either an 11T or 12T outer cog without a spacer (assuming
> that the appropriate lockring is used?

I have an 11-28 cassette on a standard 7-speed Hyperglide hub. A spacer is required, and a black
steel castellated spacer from another cassette is the right thickness. However, it fouls the three
bolt heads of the 11-28 cassette, so the bolts have to be removed. They don't serve any real
purpose, though.

 

[Sheldon Brown]

Art Harris wrote:

> I'm plan to install a 9-sp cassette with an 11T cog on my wife's bike. I didn't think that was
> going to be complicated until I read about Hyperglide "C" systems on Sheldon's "Kah Sept" page. It
> seems that a special Hyperglide "C" freehub body (with splines that don't extend to the end of the
> body) are required to accomodate an 11T cog. Otherwise, a 1 mm spacer has to be added.
>
> Then, I looked at Shimano's site, and it appears that the splines on all their modern freehubs
> don't extend to the end of the FH body.
>
> Then, in the case of the Sora Freehub, Shimano implies that an 11T cog MUST be used.
>
> Questions:
>
> 1) Can a 105 or Ultegra freehub accept either an 11T or 12T outer cog without a spacer (assuming
> that the appropriate lockring is used?

Depends on the vintage. The older ones had full-length splines, so some minor modification
is needed.

See: http://sheldonbrown.com/k7.html#hyperdrivec where it's all explained.

> 2) Why does the Sora freehub require an 11T?

It doesn't.

> Will it not accept a 12T?

It will accept any Shimano splined cassette sprocket.

Sheldon "Onze" Brown +-------------------------------------------------+
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http://captainbike.com http://sheldonbrown.com

 

[Qui Si Parla Ca]

n2ah-<< Questions:

1) Can a 105 or Ultegra freehub accept either an 11T or 12T outer cog without a spacer (assuming
that the appropriate lockring is used?

***yes

2) Why does the Sora freehub require an 11T? Will it not accept a 12T?
>><BR><BR>

It will accept either...and a 13t as well...

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(3)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Harris]

Qui si parla Campagnolo <[email protected]> wrote:
> n2ah-<< Questions:

> 2) Why does the Sora freehub require an 11T? Will it not accept a 12T?
> >><BR><BR>

> It will accept either...and a 13t as well...

Thanks for that info (and thanks to Sheldon too). The wording on Shimano's European website was
what confused me: "Flexible application - can be used with 8 or 9-speed cassette sprockets with 11T
top gear."

Art Harris