FFS - front freewheel system

"Jacobe Hazzard" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I am rebuilding an old panasonic road bike I found, and it
is equipped

with

Quoted message said:

shimano FFS, that's where the BB spindle freewheels.

This is bizarre, the chain moves when I'm coasting! What's
the purpose of such a system? When I found the bike it had
a 5 speed freewheel on the

rear

Quoted message said:

wheel, and the wheel + derailer look pretty old, not like
they were added

on

Quoted message said:

late in the life of the bike, so that makes the FFS pretty
useless.

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

Thanks guys!

Adam

According to Sheldon Brown's web-site: FFS ® Front Freewheel
System. The freewheel was built into the bottom bracket, so
that the chain would turn even when the rider was coasting.
This was to allow shifting while coasting--a solution in
search of a problem.

Apparently it wasn't terribly popular and didn't last long.
I don't know anything about it other than what I found doing
a quick goodle search. Maybe ol' Sheldon will drop
by................

Jacobe Hazzard said:

I am rebuilding an old panasonic road bike I found, and it
is equipped with shimano FFS, that's where the BB spindle
freewheels.

This is bizarre, the chain moves when I'm coasting! What's
the purpose of such a system?

Beginner cyclists don't always realize that you need to be
pedaling to shift a derailer. This was especially true of
folks who started out on internal-gear 3-speeds.

Quoted message said:

When I found the bike it had a 5 speed freewheel on the
rear wheel, and the wheel + derailer look pretty old, not
like they were added on late in the life of the bike, so
that makes the FFS pretty useless.

See: sheldonbrown.com35.htmlOpen ↗

Quoted message said:

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.

Sheldon "An Idea Whose Time Has Gone" Brown +------------------------------------------------
+
| What was the real cause of the 1861-65 war? |
| sheldonbrown.netslaverywar.htmlOpen ↗ |
+------------------------------------------------+ Harris
Cyclery, West Newton, Massachusetts Phone 617-244-9772 FAX
617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts
shipped Worldwide captainbike.comcaptainbike.comOpen ↗
sheldonbrown.comsheldonbrown.comOpen ↗

In article <[email hidden]>,

Jacobe Hazzard said:

This is bizarre, the chain moves when I'm coasting! What's
the purpose of such a system?

The idea was that the chain keeps moving, so that you can
shift when you coast, in case you find shifting while you
pedal too difficult.

Somebody must have thought it was a good one, at some
point...

--
---
"I never had to pretend I felt the lyrics. I could always
relate to the words."
-- Teddy Pendergrass

"Jacobe Hazzard" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

I am rebuilding an old panasonic road bike I found, and it
is equipped with shimano FFS, that's where the BB spindle
freewheels.

This is bizarre, the chain moves when I'm coasting! What's
the purpose of such a system? When I found the bike it had
a 5 speed freewheel on the rear wheel, and the wheel +
derailer look pretty old, not like they were added on late
in the life of the bike, so that makes the FFS pretty
useless.

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

Thanks guys!

Adam

Dear Adam,

A friend's father bought a bike equipped with this odd
system when I was in high school. We all marvelled at the
strange way that the chain kept moving, but none of us had
any idea of the purpose. Apparently, they were sold without
dealers having a clear notion, either.

Thanks for raising a long-forgotten question and getting the
others here to provide the answer.

Carl Fogel

Quoted post said:

Originally posted by Carl Fogel
"Jacobe Hazzard" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

I am rebuilding an old panasonic road bike I found, and it
is equipped with shimano FFS, that's where the BB spindle
freewheels.

This is bizarre, the chain moves when I'm coasting! What's
the purpose of such a system? When I found the bike it had
a 5 speed freewheel on the rear wheel, and the wheel +
derailer look pretty old, not like they were added on late
in the life of the bike, so that makes the FFS pretty
useless.

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

Thanks guys!

Adam

Dear Adam,

A friend's father bought a bike equipped with this odd
system when I was in high school. We all marvelled at the
strange way that the chain kept moving, but none of us had
any idea of the purpose. Apparently, they were sold without
dealers having a clear notion, either.

Thanks for raising a long-forgotten question and getting the
others here to provide the answer.

Carl Fogel

Not a longforgotten question since you can mount Powercranks with a fixie rear with similar results.

Several electric bikes, including a couple of my Currie's, use a left side electric chain drive with the freewheel attached to motor side of the chain drive. Unfortunately, another problem with these implementations are that you are still turning the second chain even when not running the electric drive so you are introducing extra frictional losses-about 1%. The analagous situation would exist on the FFS or Powercranks-fixie combinations during coasting.

Christini and Spicer AWD mountainbikes probably have similar issues with the front drive.

Carl Fogel said:

"Jacobe Hazzard" <[email hidden]> wrote in
message news:<[email hidden].-
cable.rogers.com>...

Quoted message said:

I am rebuilding an old panasonic road bike I found, and
it is equipped with shimano FFS, that's where the BB
spindle freewheels.

This is bizarre, the chain moves when I'm coasting!
What's the purpose of such a system?

----8<---cutting

Quoted message said:

Dear Adam,

A friend's father bought a bike equipped with this odd
system when I was in high school. We all marvelled at the
strange way that the chain kept moving, but none of us had
any idea of the purpose. Apparently, they were sold
without dealers having a clear notion, either.

Thanks for raising a long-forgotten question and getting
the others here to provide the answer.

I heard about this one years ago. The only advantage I
could see with this system is that it allows the rider to
shift gears while coasting, i.e. without turning the
pedals. Now why on earth someone would . . . aw, forget it
. . . ROTFL . . .

/Robert

Quoted post said:

Originally posted by Jacobe Hazzard
I am rebuilding an old panasonic road bike I found, and it
is equipped with shimano FFS, that's where the BB spindle
freewheels.

This is bizarre, the chain moves when I'm coasting!
What's the purpose of such a system? When I found the
bike it had a 5 speed freewheel on the rear wheel, and
the wheel + derailer look pretty old, not like they were
added on late in the life of the bike, so that makes the
FFS pretty useless.

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

Thanks guys!

Adam

A few years ago, the "auto bike"made use of this concept. It used a 5 speed rear cassette and there were weights on the wheel which moved toward the outer part of the wheel by centrifugal force as the speed of the bike increased. These weights were linked to the derrailuer so that as the speed increased, and the weights moved out, the chain automatically moved to a smaller cog. The reverse happened as the bike slowed down. The freewheeling chainwheel was necessary so the shifts would happen even if the rider was not pedalling. I don't know whatever became of the Autobike.
It occurs to me it might be useful on a tandem for those who prefer indepedent pedalling

Sheldon Brown <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Quoted message said:

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

Quoted post said:

Originally posted by Dan Burkhart
A few years ago, the "auto bike"made use of this concept. It used a 5 speed rear cassette and there were weights on the wheel which moved toward the outer part of the wheel by centrifugal force as the speed of the bike increased. These weights were linked to the derrailuer so that as the speed increased, and the weights moved out, the chain automatically moved to a smaller cog. The reverse happened as the bike slowed down. The freewheeling chainwheel was necessary so the shifts would happen even if the rider was not pedalling. I don't know whatever became of the Autobike.
It occurs to me it might be useful on a tandem for those who prefer indepedent pedalling

Autobike was selling by infomercial last year.

There website is still operational:
http://www.bpc.co.kr/

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" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

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:
sheldonbrown.comdynohubs.htmlOpen ↗

Jeff

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

http://www.webcyclery.com/.docs/product_id/1953/pg/product_details.html

Be Well,
Eric

Quoted post said:

Originally posted by Jeff Wills
Sheldon Brown <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Quoted message said:

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?

meb <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Jeff Wills wrote:

<snipedy-doo-dah>

Quoted message said:

Quoted message said:

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?

Aside from the fact a "5-speed fixie" would make a hash of
any conventional rear derailleur, yes. I think the purpose
of the limited freewheel was to allow the rear wheel to keep
turning if something (a pants cuff, for instance) caught in
the the chain.

Quoted message said:

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

No.

Quoted message said:

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

AFAIK, they were comparable. They were both solid
chunks of steel.

Jeff

Quoted message said:

Jeff Wills said:

Quoted message said:

> Also, where is the front freewheel exactly? Is

the BB shell the

Quoted message said:

Quoted message said:

Quoted message said:

> standard size, or is there something special

about it?

Quoted message said:

Quoted message said:

Sheldon Brown <[email hidden]> wrote in
message news:<[email hidden]>...

Quoted message said:

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 said:

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

Quoted post said:

Originally posted by A Muzi

B Jeff Wills said:

Quoted message said:

Quoted message said:

> Also, where is the front freewheel exactly? Is

the BB shell the

Quoted message said:

Quoted message said:

Quoted message said:

> standard size, or is there something special

about it?

Quoted message said:

Quoted message said:

Sheldon Brown <[email hidden]> wrote in
message news:<[email hidden]>...

Quoted message said:

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 said:

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 [/B]

Not sure why the term fixie is missused. Is it because a 5 speed non-freewheeling drive (times any crankset ring quantities) is not a “fixie” if gears can be changed?

Regarding the tensioner issue raised: I was considering constructing a tensioner from the RANS double idler assembly http://www.shoprans.com/DriveLine.asp configured to move to take in tension from sprocket changes as well as allow the return chain side to switch to tension when the crank speeds slow below wheel speed. The double idlers are designed to work on the chain drive side as well as return side. Is there a nonobvious tensioner issue with “fixies” overlooked?

This would be tried on a recumbent.

-snip much-

Quoted message said:

Quoted message said:

meb said:

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?

Quoted message said:

A Muzi said:

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.

-snip-

meb said:

Not sure why the term fixie is missused. Is it because a 5
speed non- freewheeling drive (times any crankset ring
quantities) is not a “fixie” if gears can be changed?

-snip-

The FFS freewheels coasts. It's a freewheel, not fixed.

--
Andrew Muzi www.yellowjersey.org Open every day since 1
April, 1971

Quoted post said:

Originally posted by A Muzi
-snip much-

Quoted message said:

Quoted message said:

meb said:

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?

Quoted message said:

A Muzi said:

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.

-snip-

meb said:

Not sure why the term fixie is missused. Is it because a 5
speed non- freewheeling drive (times any crankset ring
quantities) is not a “fixie” if gears can be changed?

-snip-

The FFS freewheels coasts. It's a freewheel, not fixed.

--
Andrew Muzi www.yellowjersey.org Open every day since 1
April, 1971

So a Schlumpf BB drive with fixie hub is semantically a fixie even though multi speed.

Quoted message said:

So a Schlumpf BB drive with fixie hub is semantically a
fixie even though multi speed.

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.