Oval crankshaft

The crank itself is pretty standard, it is the chain rings that are not (I am
not sure about the inner which may be circular). These are Shimano Biopace
rings and the intent was to deliver a more constant power output through out
the crank's rotation - trying to eliminate top-dead-center, I guess. They were
made for at least a few years but have since died away (although something like
them has been used recently by a couple pro racers in specific events). At any
rate, some folks love them, some hate them. I have no personal experience. But
I doubt the feel that much different than standard, circular rings or that they
would offer much disadvantage or advantage to you in the type of riding you
describe. Of course, if you do not like the oval ring(s), you can easily
replace them with circular rings.

Charlie S. said:

I apologize in advance. I realize this group is not for advice about sale
items, but I have technical question about a bike I am thinking of buying
and would like some input.

Saw a 20 year old Raleigh chrome alloy Super Sport for sale at a yard sale
tonight for a $100. The owner recently put in an oval crank. It's a
Bio____? (Sorry, don't know the full name.)
Seemed kind of an odd set up, but he said it allowed you to put more power
into the pedaling.
Didn't get to ride the bike as the front tire was low on air. Plan to bring
my bike pump tomorrow to test ride it. The bike seems like a pretty good
deal as it had a nice feel, new parts, like new wheels, seat post and this
crank. I'm going to offer $75. But, I don't know anything about these oval
cranks. Are they any good? Do they put more pressure on your knees? Do
they feel weird riding? Or, are their any other problems associated with
this type of crank?

I don't have need for a racing type bike. All I do is go on relatively flat
trails about 20-25 miles. I currently have a much older steel bike. It's
starting to feel too heavy for my aging body. I've had it for 28 years.
It's served me well as I just use it to work out. Thought of getting
something lighter. But, I don't like the feel of some of these new light
bikes. I'm hoping this bike will suit my needs.

"David White" wrote: (clip) But, I don't know anything about these oval
cranks. Are they any good?
^^^^^^^^^^^^^^^^^
Not really. They were a flop, and gradually became rounder with the model
changes, and then disappeared. If you did a blind test, I'll bet you
couldn't tell which bike had the Bio-pace. I wouldn't base the decision to
buy or not buy the bike on that factor.

Interesting to see that Bobby Julich rides a Bio-Pace-like chainring,
though. It's called a Harmonic or O.Symetric. It seems way more ovalized
than the Bio-Pace, as I recall them. Wonder what the differences are...

--
---------------------------------------------------------------------------------
"Be bold, and mighty forces will come to your aid"

-Anthony Hopkins
"Leo Lichtman" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"David White" wrote: (clip) But, I don't know anything about these oval
cranks. Are they any good?
^^^^^^^^^^^^^^^^^
Not really. They were a flop, and gradually became rounder with the model
changes, and then disappeared. If you did a blind test, I'll bet you
couldn't tell which bike had the Bio-pace. I wouldn't base the decision
to buy or not buy the bike on that factor.

"Ed Viladevall" wrote: Interesting to see that Bobby Julich rides a
Bio-Pace-like chainring, though. It's called a Harmonic or O.Symetric. It
seems way more ovalized than the Bio-Pace, as I recall them. Wonder what
the differences are...
^^^^^^^^^^^^^^^^^^
I'm not familiar with O.Symetric, but I do have a set of elliptical
chainrings on a Bridgestone mountain bike. At a glance they may resemble
Biopace, but there is a world of difference. Biopace are not oval--they are
a weird shape that is supposed to make your foot move as though you were
walking. The elliptical chainrings are positioned with their long axis at
90 degrees to that of the Biopace, and are designed to give you a longer
effective power stroke by getting you through top-dead-center faster. It's
not such a big deal on the big ring or the middle ring, but really helps in
the "granny" range on hard climbs, when you are pedalling slowly.

29 Jul 2005 22:49:47 GMT 'Charlie S. said:

Saw a 20 year old Raleigh chrome alloy Super Sport for sale at a yard sale
tonight for a $100.

Could it be a Schwinn Super Sport? Those were made in Chicago from
4130 Chrome Moly Steel tubing. They were quite nice frames, actually
hand brazed lugless. The features varied over the years, with the
earlier ones generally being nicer than the late ones.

Quoted message said:

The owner recently put in an oval crank. It's a
Bio____? (Sorry, don't know the full name.)

BioPace? They have a few vocal advocates, but most people don't put
much faith in them.

Quoted message said:

Seemed kind of an odd set up, but he said it allowed you to put more power
into the pedaling.

If they really worked we'd see some racers taking this advantage, but
that hasn't happened. Interestingly, this concept has been
reintroduced as "new" almost every 20 years over more than a century.

-
-----------------------------------------------
Jim Adney [email hidden]
Madison, WI 53711 USA
-----------------------------------------------

Leo Lichtman said:

If you did a blind test, I'll bet you
couldn't tell which bike had the Bio-pace. I wouldn't base the decision
to buy or not buy the bike on that factor.

Me either, though I think they feel very different and could tell the
difference blind in two seconds.

I'd hate to have to ride a bike with Biopace and be forced to spin at a
high cadence, it's really awkward and lumpy.

But, they're kinda nice for low cadence stuff, especially off roading or
for folks that like to pedal more slowly, perhaps less than 70 rpm.

I've got a utility bike with them and they do seem to be nicer to the
knees, but I don't ride that bike further than the closest beer/ice
cream/dog food store. LOL

As mentioned before, if you absolutely hate it, rings are pretty
affordable.

Buy the bike if it fits.

Charlie S. said:

I apologize in advance. I realize this group is not for advice about sale
items, but I have technical question about a bike I am thinking of buying
and would like some input.

Saw a 20 year old Raleigh chrome alloy Super Sport for sale at a yard sale
tonight for a $100. The owner recently put in an oval crank. It's a
Bio____? (Sorry, don't know the full name.)
Seemed kind of an odd set up, but he said it allowed you to put more power
into the pedaling.
Didn't get to ride the bike as the front tire was low on air. Plan to bring
my bike pump tomorrow to test ride it. The bike seems like a pretty good
deal as it had a nice feel, new parts, like new wheels, seat post and this
crank. I'm going to offer $75. But, I don't know anything about these oval
cranks. Are they any good? Do they put more pressure on your knees? Do
they feel weird riding? Or, are their any other problems associated with
this type of crank?

I don't have need for a racing type bike. All I do is go on relatively flat
trails about 20-25 miles. I currently have a much older steel bike. It's
starting to feel too heavy for my aging body. I've had it for 28 years.
It's served me well as I just use it to work out. Thought of getting
something lighter. But, I don't like the feel of some of these new light
bikes. I'm hoping this bike will suit my needs.

Sheldon Brown has an excellent article about Biopace:

http://sheldonbrown.com/biopace.html

and is a regular contributor to this NG. Personally, I have an older
hybrid bike with Biopace rings, but I don't really notice a difference
from round chainrings. I primarily use this bike for communting, on
flat roads at moderate RPMS.

I wouldn't worry too much about the rings. Test ride the bike, and if
you like it, buy it.

"Charlie S." <[email hidden]> wrote in message
news:foyGe.29$2y2.4@trndny02...

Quoted message said:

I apologize in advance. I realize this group is not for advice about sale
items, but I have technical question about a bike I am thinking of buying
and would like some input.

Saw a 20 year old Raleigh chrome alloy Super Sport for sale at a yard sale
tonight for a $100. The owner recently put in an oval crank. It's a
Bio____? (Sorry, don't know the full name.)
Seemed kind of an odd set up, but he said it allowed you to put more power
into the pedaling.
Didn't get to ride the bike as the front tire was low on air. Plan to
bring
my bike pump tomorrow to test ride it. The bike seems like a pretty good
deal as it had a nice feel, new parts, like new wheels, seat post and this
crank. I'm going to offer $75. But, I don't know anything about these
oval
cranks. Are they any good? Do they put more pressure on your knees? Do
they feel weird riding? Or, are their any other problems associated with
this type of crank?

I don't have need for a racing type bike. All I do is go on relatively
flat
trails about 20-25 miles. I currently have a much older steel bike. It's
starting to feel too heavy for my aging body. I've had it for 28 years.
It's served me well as I just use it to work out. Thought of getting
something lighter. But, I don't like the feel of some of these new light
bikes. I'm hoping this bike will suit my needs.

I've seen a Bio-Pace triple crankset fetch $52 on ebay, so they have some
value.

No news on the bike. I called today and didn't hear back. Will let you
know what happens.

I am not clear on the bicycle terminology. From what I understand the
crank is the arm that the pedal attaches to. And, includes the chain rings?
(what the chain rests on in the front end of the bike).

I guess what I really want to know is, if I didn't like this Biopace, would
I have to replace the crank (arm) and chain rings? It is all one piece?
What is the price for a decent lower end model?

The arm or crank looked pristine as though it were well machined. I didn't
look real carefully, but the chain rings didn't look as new. (could be
wrong here)

In response to another poster, he definitely indicated it was a Raleigh....
I may be off if he said it was a super sport. Did a Google search, came up
with the Schwinn, not a Raleigh Super Sport. Maybe I didn't hear him right.

After reading all the posts and links, I get the feeling the Biopace won't
make any difference to my type of riding. (Then again, if I start passing
you all on the trail, I'll know I'm on to something:-)

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

Quoted message said:

The crank itself is pretty standard, it is the chain rings that are not (I
am not sure about the inner which may be circular). These are Shimano
Biopace rings and the intent was to deliver a more constant power output
through out the crank's rotation - trying to eliminate top-dead-center, I
guess. They were made for at least a few years but have since died away
(although something like them has been used recently by a couple pro
racers in specific events). At any rate, some folks love them, some hate
them. I have no personal experience. But I doubt the feel that much
different than standard, circular rings or that they would offer much
disadvantage or advantage to you in the type of riding you describe. Of
course, if you do not like the oval ring(s), you can easily replace them
with circular rings.

Charlie S. said:

I apologize in advance. I realize this group is not for advice about
sale
items, but I have technical question about a bike I am thinking of buying
and would like some input.

Saw a 20 year old Raleigh chrome alloy Super Sport for sale at a yard
sale
tonight for a $100. The owner recently put in an oval crank. It's a
Bio____? (Sorry, don't know the full name.)
Seemed kind of an odd set up, but he said it allowed you to put more
power
into the pedaling.
Didn't get to ride the bike as the front tire was low on air. Plan to
bring
my bike pump tomorrow to test ride it. The bike seems like a pretty good
deal as it had a nice feel, new parts, like new wheels, seat post and
this
crank. I'm going to offer $75. But, I don't know anything about these
oval
cranks. Are they any good? Do they put more pressure on your knees? Do
they feel weird riding? Or, are their any other problems associated with
this type of crank?

I don't have need for a racing type bike. All I do is go on relatively
flat
trails about 20-25 miles. I currently have a much older steel bike.
It's
starting to feel too heavy for my aging body. I've had it for 28 years.
It's served me well as I just use it to work out. Thought of getting
something lighter. But, I don't like the feel of some of these new light
bikes. I'm hoping this bike will suit my needs.

Technically, the arms are the cranks. The chain runs along the chain rings
which attach to the cranks at the spyder using chain ring bolts. The whole
shebang is called a chainset or a crankset. If you do not like the Biopace
chain rings, they are easily replaced with circular rings. However, I don't
think you'll care enough to bother. The rings may show more wear and tear than
the arms and this is normal. They certainly get more dirty but these are easily
cleaned. Hope this helps.

Charlie S. said:

No news on the bike. I called today and didn't hear back. Will let you
know what happens.

I am not clear on the bicycle terminology. From what I understand the
crank is the arm that the pedal attaches to. And, includes the chain rings?
(what the chain rests on in the front end of the bike).

I guess what I really want to know is, if I didn't like this Biopace, would
I have to replace the crank (arm) and chain rings? It is all one piece?
What is the price for a decent lower end model?

The arm or crank looked pristine as though it were well machined. I didn't
look real carefully, but the chain rings didn't look as new. (could be
wrong here)

In response to another poster, he definitely indicated it was a Raleigh....
I may be off if he said it was a super sport. Did a Google search, came up
with the Schwinn, not a Raleigh Super Sport. Maybe I didn't hear him right.

After reading all the posts and links, I get the feeling the Biopace won't
make any difference to my type of riding. (Then again, if I start passing
you all on the trail, I'll know I'm on to something:-)

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

Quoted message said:

The crank itself is pretty standard, it is the chain rings that are not (I
am not sure about the inner which may be circular). These are Shimano
Biopace rings and the intent was to deliver a more constant power output
through out the crank's rotation - trying to eliminate top-dead-center, I
guess. They were made for at least a few years but have since died away
(although something like them has been used recently by a couple pro
racers in specific events). At any rate, some folks love them, some hate
them. I have no personal experience. But I doubt the feel that much
different than standard, circular rings or that they would offer much
disadvantage or advantage to you in the type of riding you describe. Of
course, if you do not like the oval ring(s), you can easily replace them
with circular rings.

Charlie S. said:

I apologize in advance. I realize this group is not for advice about
sale
items, but I have technical question about a bike I am thinking of buying
and would like some input.

Saw a 20 year old Raleigh chrome alloy Super Sport for sale at a yard
sale
tonight for a $100. The owner recently put in an oval crank. It's a
Bio____? (Sorry, don't know the full name.)
Seemed kind of an odd set up, but he said it allowed you to put more
power
into the pedaling.
Didn't get to ride the bike as the front tire was low on air. Plan to
bring
my bike pump tomorrow to test ride it. The bike seems like a pretty good
deal as it had a nice feel, new parts, like new wheels, seat post and
this
crank. I'm going to offer $75. But, I don't know anything about these
oval
cranks. Are they any good? Do they put more pressure on your knees? Do
they feel weird riding? Or, are their any other problems associated with
this type of crank?

I don't have need for a racing type bike. All I do is go on relatively
flat
trails about 20-25 miles. I currently have a much older steel bike.
It's
starting to feel too heavy for my aging body. I've had it for 28 years.
It's served me well as I just use it to work out. Thought of getting
something lighter. But, I don't like the feel of some of these new light
bikes. I'm hoping this bike will suit my needs.

On Sat, 30 Jul 2005 23:10:04 GMT, "Charlie S." <[email hidden]>

Quoted message said:

I am not clear on the bicycle terminology. From what I understand the
crank is the arm that the pedal attaches to. And, includes the chain rings?
(what the chain rests on in the front end of the bike).

A crank is just the arm, a crank*set*, which is what they're generally
sold in, is both crank arms and usually a set of chainrings. The bottom
bracket is the axle (or possibly spindle) that keeps both cranks together
and the ball bearings it runs on.

Jasper