FFS - front freewheel system

Thanks everyone, you answered all my questions.

I found something else interesting today, a dynohub front wheel. I know what
that's for. There are a lot of interesting things getting thrown out if you
stop and look!

Adam

"Jacobe Hazzard" wrote in message able.rogers.com...
Thanks everyone, you answered all my questions.

I found something else interesting today, a dynohub front wheel. I know what
that's for. There are a lot of interesting things getting thrown out if you
stop and look!

Adam

A working Dynohub would be neat- but if it's been dissassembled, the
magnets may have been ruined (I think). Sheldon may be able to help:
http://www.sheldonbrown.com/dynohubs.html

Jeff

Trials riders are using a similar system now. They attach freewheels to
the cranks.

http://www.webcyclery.com/.docs/prod...t_details.html

Be Well, Eric



--

Jeff Wills wrote:
Sheldon Brown wrote in message
...
Also, where is the front freewheel exactly? Is the BB shell the
standard size, or is there something special about it?

It's attached to the bottom bracket spindle. This precluded use of a
standard square taper BB for clearance reasons, so they use an early
"Octalink" splined setup that turned out to be rather unsatisfactory.

There was also a variant that used a one-piece crank, fitting into a
standard American-type bottom bracket shell. I used these to make
coastable kidback tandem cranks when my kids were little.
To answer a question Sheldon missed: the BB shell on your Panasonic
should be a standard 68mm width English thread unit. IIRC, once you get
the arms off the spindle, the left cone unscrews from the spindle and
the bearings fall on the floor. After removing the spindle to the right
(and dropping more bearings), you'll see that the cups threaded in the
frame have internal splines. I *think* the tool that fits these splines
is the standard Shimano freewheel removal tool.
A note: the rear cogset had a limited freewheel action built into it.
If something jammed the chain, this would allow the rear wheel to
continue to turn. It felt like a conventional freewheel with *really*
tight bearings.
Jeff



Am I correct in assuming this limitted freewheel action would preclude
the rear cogset from being used for a 5 speed fixie?

Was this limitted freewheel action limitted enough to provide
significant braking?

Was there any weight difference on the FF rear 5 speed cogset from a 5
speed freewheel or were they comparable?



--

Jeff Wills wrote:
Also, where is the front freewheel exactly? Is
the BB shell the
standard size, or is there something special
about it?


Sheldon Brown wrote in message
...

It's attached to the bottom bracket spindle. This precluded use of a
standard square taper BB for clearance reasons, so they use an early
"Octalink" splined setup that turned out to be rather unsatisfactory.
-snip informative stuff-

meb wrote:
Am I correct in assuming this limitted freewheel action would preclude
the rear cogset from being used for a 5 speed fixie?
Was this limitted freewheel action limitted enough to provide
significant braking?
Was there any weight difference on the FF rear 5 speed cogset from a 5
speed freewheel or were they comparable?

The freewheel for an FFS/PPS has stiffer than normal
resistance and will allow a chain to bunch up when coasting
if you remove the FFS/PPS crank system.

If you set it up as a single speed ( You misuse the term
"fixie") by shortening the chain to one of the five
sprockets, yes, you can ride it effectively. Just don't
include a derailleur or tensioner unless you have the
special crank assembly.

The crank spline is the "Selecta" pattern which started the
early "standard" called "Octa-8" long before "octalink."

No, you will get no noticeable braking effect. Keep your
front caliper.

On a hi-ten frame with steel hubs, cranks and rims the
freewheel weight, while substantial, isn't all that
significant.

You may substitute a normal 5 or 6 freewheel ( or even a
single for that matter) on the hub you have.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Adam Rush wrote:
Schlumpf themselves say that is it right out. From their FAQ:
"9. Can speed-drive be used with a fixed wheel cycle?
"No. In reverse direction, there musn't be full load. It's o.k. for
actuating a coaster brake, but not for high torques during long
operation periods."
If anybody could give me some technical reasons for this FAQ answer,
other than that they are covering their asses, I would appereciate it.

I'm not sure what you mean; manifestly it's harder to design a planetary
gear that must withstand high torque in both directions.
--
David Damerell flcl?

David Damerell wrote:

Adam Rush wrote:
Schlumpf themselves say that is it right out. From their FAQ:
"9. Can speed-drive be used with a fixed wheel cycle?
"No. In reverse direction, there musn't be full load. It's o.k. for
actuating a coaster brake, but not for high torques during long
operation periods."
If anybody could give me some technical reasons for this FAQ answer,
other than that they are covering their asses, I would appereciate it.

I'm not sure what you mean; manifestly it's harder to design a planetary
gear that must withstand high torque in both directions.

Maybe if you know the details of how they are designed. I never realized
they were not symmetrical.

--
Benjamin Lewis

Amoebit:
Amoeba/rabbit cross; it can multiply and divide at the same time.