freewheels and threaded hubs....

Helmut Springer writes:

Jasper Janssen wrote:
Are threaded track cogs typically made of aluminum?

No, but track hubs are.

Right, and I think Jobst's point was that the steel cogs would fret
into the aluminum of the hub, especially the S-A design which has only
three small "splines." Cassette hubs with aluminum bodies and steel cogs
can have this problem (I see this on my 1999 Campy Chorus)- the cogs
"bite" into the softer aluminum and leave visible marks, and are a
little difficult to get off at times. It's necessary to torque down
the cog retainer firmly to minimize this.

Helmut Springer wrote:
Jasper Janssen wrote:

Are threaded track cogs typically made of aluminum?


No, but track hubs are.

Am I mis-remembering? I thought I had used both steel and aluminum
track cogs, in my brief fling with fixed-gear, 20 years ago. I thought
the aluminum cog was a Campy, not some rare, exotic one-off affair.

Mark

"Baird Webel" wrote:

Miche makes the splined system. I have no idea if it is the same
spline pattern as the sturmey.

It isn't: the Miche sprockets use seven evenly-spaced splines, while
Sturmeys use three.

Pictures he

http://www.sheldonbrown.com/harris/fixed-sprockets.html

James Thomson

Jasper Janssen writes:

Yep, the ones made for that thread pitch. Track hubs are just
normal freewheel pitch sections, made shorter so the reverse
thread lockring can go on. It is still tall enough for a single
speed freewheel.

Isn't it more like freewheel threads are track threads made longer
and without the lockring thread? Seems like the track thread was
there first -- viz the old Sturmeys and coasters with thread to
screw the cog on, rather than the newer splines.

Incidentally, why aren't there Fixie hubs with Sturmey & co
splines instead of the archaic threaded system? I mean, the cogs
are a lot cheaper, they have built-in chainline adjustment with
the raised shoulders and the two 1 mm spacers, and it's just an
objectively better design, especially for fastening on cogs that
might get reverse pressure. They're not used on hundreds of
millions of coaster brake hubs for nothing, after all.

This type of attachment only works well on centered chain lines and
only on steel. Slide-on sprockets that we have on cassettes today
were formerly secured by screwing on the last sprocket to prevent
fretting damage that would otherwise occur. It was only recently
that someone devised the detente style cover-nut that holds today's
gear clusters together. Had someone invented that forty years ago,
you probably wouldn't need to ask. Progress is slow.

Seems to me that a Sturmey three speed or a coaster brake are pretty
much identical in chainline etc. considerations to a track hub. They
don't seem particularly prone to fretting with the splined +
circular spring attachment. Are threaded track cogs typically made
of aluminum?

That is true but when you already have a thread standard, it's easy to
just use it on track hubs. Hubs were threaded and could accept a
track sprocket of a freewheel. Many of these were ridden with a
one-speed freewheel. That's why road bicycles had horizontal dropouts
for all those years, so you could ride a fixed gear. It's all tradition.

Typically I broke Campagnolo axles on my road bicycle regularly when I
had horizontal dropouts. As I mentioned, I copied the Diamant
vertical dropout from East Germany in 1960 and the rave was on. You
see how hard it is to introduce reasonable technical ideas even here on
wreck.bike.

Jobst Brandt

Mark Janeba wrote:
Are threaded track cogs typically made of aluminum?

No, but track hubs are.

Am I mis-remembering? I thought I had used both steel and
aluminum track cogs, in my brief fling with fixed-gear, 20 years
ago. I thought the aluminum cog was a Campy, not some rare,
exotic one-off affair.

Well, the question was "typically" 8)

I can't tell if there were aluminum track cogs for racing, so far
I've seen only steel ones and I'd assume aluminum to wear pretty
fast?

--
MfG/Best regards
helmut springer

Jobst Brandt wrote:
It was only recently that
someone devised the detente style cover-nut that holds today's gear
clusters together. Had someone invented that forty years ago, you
probably wouldn't need to ask. Progress is slow.

will 80-odd years ago do?

www.m-gineering.nl/retrog.htm


---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

On 2005-11-28, Helmut Springer wrote:

Mark Janeba wrote:
Are threaded track cogs typically made of aluminum?

No, but track hubs are.

Am I mis-remembering? I thought I had used both steel and
aluminum track cogs, in my brief fling with fixed-gear, 20 years
ago. I thought the aluminum cog was a Campy, not some rare,
exotic one-off affair.

Well, the question was "typically" 8)

I can't tell if there were aluminum track cogs for racing, so far
I've seen only steel ones and I'd assume aluminum to wear pretty
fast?

Campy and Zeus both made alloy track cogs, and yes they did wear pretty
quickly. But there was an extreme lightness fad going on in the mid-late
70s and companies were happy to oblige with lightweight, fast wearing
parts.

--

John )

Marten Gerritsen writes:

It was only recently that someone devised the detente style
cover-nut that holds today's gear clusters together. Had someone
invented that forty years ago, you probably wouldn't need to ask.
Progress is slow.

will 80-odd years ago do?
www.m-gineering.nl/retrog.htm

No, because they didn't have a detent lock nut as is evident from the
mashed removal slot in the retaining nut. Lotta force and pounding!

Jobst Brandt

On 28 Nov 2005 20:29:19 GMT, wrote:

No, because they didn't have a detent lock nut as is evident from the
mashed removal slot in the retaining nut. Lotta force and pounding!

What do you mean by detent lock nut? The splines between it and the tool?

Jasper

Jasper Janssen wrote:
What do you mean by detent lock nut? The splines between it and
the tool?

Nope, the teeth on locknut and freehub, the ones that go "krkrkrkrk"
when you tighten it...

--
MfG/Best regards
helmut springer