Conference noted::bicycle

    	A friend of mine bought a bike this spring that came with those
    rings.  After two weeks of riding, he bought some round chainrings,
    and pitched the biopace.
    
    You should have seen him try to spin - especially in the small ring.
    It was funny to watch, but perhaps not so great if you're the one
    putting on the show.

< Note 441.0 by DIXIE1::LINDQUIST >
                            -< BioPace Chain Rings >-

There are numerous references to BioPace throughtout this conference.  
Unfortunately, I don't remember which notes.  I'll leave it to you to find 
them.  I will give you my opinion (also stated in other notes):

I've been riding BioPace for over 2 years and love them.  I've got them on 
both my race bike and my mtn bike.  On the race bike, I regularly spin at 
95-105 cadence.  This weekend, just fooling around, I got my cadence up to 160 
in the small chainring (42 teeth).  I obviously had no problem spinning them. 
(see .1!?)  At the time I bought them, my normal 'spin' was about 93, so I've 
increased it while riding the BioPace.

I like them because I don't notice them when I'm spinning (in ANY gear!), but
when I need a little power and drop my cadence, I notice the increase in 
power.  Especially when standing.  I can probably use the next higher gear 
when standing using Biopace, as opposed to round rings, tho I've never tested 
that theory.  I'll never go back to round rings.  They don't make any sense 
compared to Biopace, esp when you examine the physics and aerodynamics behind 
them (yes...aerodynamics, as related to the movement of the entire bike and 
rider thru the air, not just the aerodynamics of the crankset)

    
    
       WHAT I HAVE HEARD ABOUT BIOPACE CHAINRINGS FROM A NUMBER OF
    DIFFERENT SOURCES IS THAT THEY ARE GOOD FOR LOWER RPM GRINDING ON
    THE SMALL RING AND NOT SO GOOD FOR SPINNING ON THE BIG CHAINRING
       THE PEOPLE THAT I HAVE TALKED TO THAT USE THEM HAVE BEEN USING
    A ROUND BIG CHAINRING AND A BIOPACE SMALL CHAINRING. IF YOU LOOK
    AT BIOPACE CHAINRINGS CLOSELY YOU WILL SEE THAT AS THE RINGS BECOME
    LARGER THE SHAPE BECOMES MORE AND MORE ROUND. AS SPINNING BECOMES
    MORE SMOOTHER AT HIGHER RPM'S THE NEED FOR THE EXTRA MECHANICAL
    ADVANTAGE DECREASES AND AN ELIPTICAL RING SUCH AS BIOPACE BECOMES
    LESS OF AN ADVANTAGE.
       SO MY ADVICE FOR TRYING OUT THE RINGS IS TO JUST PURCHAS A SMALLER
    ONE AND TRY IT FOR A WHILE, IF YOU GET A REAL DRASTIC DIFFERANCE
    TRY A LARGE ONE NEXT, BUT IF YOU LIKE IT THE CASH LOSS IS KEPT TO
    A MINIMUM.
    
                                              KEEP ON SPINNING
                                                   JOHN C.
    

    Those with (or looking for) a mountain bike take note.  I have biopace
    chainrings with Deore XC brakes that attach down by the bottom bracket.
    At certain times when I am shifting onto my smallest chainring the
    chain gets caught between the brake and the small chainring.  
    Backpeddling right when you notice it should unjam it.  I have talked
    to other users and shops and there tends to be a consistant opinion
    that the problem is caused by the biopace rings.  More tension on
    the rear derailleur may help the problem but not prevent it.
    Have others had similar problems?
    
    steve
    

    
    RE: -1  Please try to avoid all caps, it's rough on the eyes and
            reserved for YELLING according to Notes etiquette.
    
    
    As I mentioned in an earlier note (I think it was on hill climbing
    techniques originally) I made the switch to Biopace and I am very
    pleased with the results. I was warned that I might need a break-in
    period initially, if I bought them at the same gear ratio that I
    was accustomed to. I did find that I fatigued a little earlier for
    the first few weeks (that split second pause per rotation in the
    round rings was evident after I went to off-round) but I have since
    adapted. As far as the "spinning" mentioned in .1, I have no idea
    what he's talking about.
    
    Well worth the investment. I wouldn't switch back.
    
    							* MAC *

Re: .3

	Great technical description, and suggestion.  Assuming that .0 is
	considering the Biopace investment for a road bike, that sounds
	like the route I would take.

Re: .4

	Hmmm...this has happened to me a couple of times.  I've got a 
	Specialized Stumpjumper with Biopace and the [now] famous
	Shimano "U brake".  Never had it happen with my previous 
	mountain bike (round rings, and rear cantilevers).  Maybe 
	you're onto something here, but this has never happened with
	enough frequency to bother me.  Every bike I've ever owned has
	had at least 1 derailleur/chainring/chain quirk.

Re: all...

	I really like Biopace, but I ride a mountain bike primarily, and
	I have also heard them praised mostly for low cadence benefits.
	After getting used to them, I wouldn't buy a mountain bike without
	them. 

.jim

    	I'm glad that you folks like them.  Marty, the friend mentioned
    earlier, got the bike in the early spring when everyone was using
    small gears.   In a paceline, he couldn't match everyone else's
    cadence and had to use slightly higher gears.  When he went back
    to round chainrings, the problem went away and he looked smoother.
    
    	Maybe it was improved technique, but it sure didn't seem like
    it at the time.  Lets agree to disagree - I'll never try them.

    	What's the effect of the Biopace rings on a recumbent machine?
    	Has anybody ever tried THAT combination?
    

    re .4
    
    I just bought a Fisher Hoo-Koo-E-Koo (don't laugh ;-) ) mountain bike.
    When I asked someone else who owned one if they had any problems
    they told me of the problem you describe and said that it was a
    common problem with Hoo-Koo-E-Koo's.  Looks like it's a common problem
    with bio-pace.  I've had it happen once when down shifting to the
    small chain ring rather quickly.  I've decided to just try and go
    easy when doing that gear change.
    
    Mark

    		Shimano has introduced a Dura-Ace version of Bio-Pace, 
    which is more round to suit "the cadences usually used by racing 
    cyclists."[spinning] They mention that that standard Bio-Pace was 
    designed for the cadences of "recreational, off-road, and triathlon 
    cyclists."[mashing]  To me, it sounds like they never intended the 
    original for spinning.  I feel vindicated.

    After two months of riding Biopace at the end of last year, I've
    developed some pretty strong impressions.  These gears are great
    for TTs, tris, or other grind-it-out competitions.  They really
    do maximize output at the 70-80 rpm range, and improve
    out-of-the-saddle climbing.  For training, however, they're a 
    disaster.  They encourage a cadence that's close to the anerobic
    threshold, and seem to break down muscle tissue when used on a 
    daily basis.  I had fun with them, but they probably won't see a 
    lot of use on my road bike this year.  

    The reason you can't spin at high (120) revs with the original
    Biopace is that it smooths out the resistance of the stroke too
    much.  At such high speeds, your legs rely on peaks of resistance
    to keep their rhythm.  I felt like a little kid spinning a hand
    mixer when I tried to spin with the biopace -- it seemed pointless,
    like I was not putting power to the ground.  Biopace makes you
    crave the power-stroke cadence....
    
    I'm interested in the Dura Ace approach.  Maybe they've worked
    out a happy medium.  At least for me, Biopace has proved its 
    worth in special cases -- a little more refinement, and it could
    have general use.
    
    MATT

< Note 441.11 by CIMNET::MJOHNSON "Matt Johnson" >
                           -< A round for the road >-

I'm interested in your Biopace opinions.  I've been riding them for 3-4 years 
and have no trouble spinning either the 42 or 52 @100-105 rpm.  I've gotten 
them as high as 160 rpm, but was just screwing around.  My training volume has 
been rather light (120m avg) but I was able to do a 5:27 Century off of it. (I 
was also running alot).  So I've been rather successful training with Biopace, 
at least by my definition.  What do you mean by:

 "They encourage a cadence that's close to the anerobic threshold, and seem to 
  break down muscle tissue when used on a daily basis."  

I think it depends on what gear you're spinning at what cadence whether one 
approaches one's anerobic threshold.  Your statement seems to simplistic.

Do you spin at 120 most of the time?  I don't know anyone that spins that high 
regularly.  I think I've heard of track sprinters spinning that fast, but not 
roadies.

Its interesting to me that Shimano said the biggest change was on the 42 ring 
because that's the one that caused the most problems.  I can spin the 42 just 
as fast as the 52.  That tells me that its more a question of what you learn 
on.  I only started serious riding once I got the Biopace, so I never 
developed a good spin on round rings.  I assume you've got a lot of miles on 
round rings...maybe you just need more miles to get used to them.

Kevin

    My theory is this: having been brought up on round rings, my body
    selects its cadence by subconsciously gauging its effort at the
    peak part of the stroke.  Through years of habit, I maintain a 
    constant cadence this way without thinking about it.

    Then Biopace comes along, and reduces the effort at the point of
    the stroke that previously was the peak.  Not understanding that
    this is actually good for them, my stupid muscles demand that
    I increase the effort at that part of the stroke.  So I shift up.
    Now my legs say they feel happy, but I'm turning 75rpm.  Meanwhile,
    I'm exhausting them at all the other points of the stroke, where
    Biopace has distributed the extra load, and where my legs aren't
    used to supplying the effort.  I end up going faster, for a time,
    but I break myself down in the end. 
    
    I've tried to hold 90-100 rpm cadences with Biopace, but I have
    to THINK about it to do it.  Whenever I look down, it's back to
    75.  I've also learned to value that 1/4 second rest each leg gets
    per stroke on round rings.  
    
    Maybe if I was born riding Biopace, my synapses would obey the 
    rules of cadence better.  But I'm a biker and runner used to 
    muscle strokes that peak in certain places -- running is probably
    an even more extreme case.  (Right now I'm trying to picture Biopace
    shoes....)
    
    Old habits die hard,
    
    MATT