Conference noted::bicycle

    	These are the assumptions that I used to calculate the relative power
  output of bare pedal vs. w/toe-clip vs. w/cleats.

	Key: 0 degrees is top, 90 deg is forward (middle of power stroke), 180
    deg. is bottom, 270 deg is at back coming up, etc.

 Bare Pedal: 5 # downward pressure everywhere except:
	     transition from 5 # to 35 # from 10 deg to 20 deg
	     35 # constant from 20 deg to 160 deg
	     transition from 35 # to 5 # from 160 deg to 170 deg

 Toe Clip:   0 # at 0 deg to 5 deg
             transition from 0 # to 35 # from 5 deg to 20 deg
             35 # constant from 20 deg to 160 deg
             transition from 35 # to 0 # from 160 to 170 deg
             0 # at 170 deg to 185 deg
             transition from 0 # to 5 # up from 185 deg to 190 deg
             5 # up from 190 deg to 350 deg
             transition from 5 # up to 0 from 350 deg to 355 deg
             0 # at 355 deg to 360/0 deg

 Cleat:      same vertical pressures as above (resultant = Pv X sin angle)
		plus the following horizontal forces (res. = Ph X cos angle)
	     transition from 0 # to -10 # at 135 deg to 155 deg
             -10 # from 155 deg to 215 deg
             transition from -10 # to 0 at 215 deg to 235 deg
	     0 # from 235 deg to 330 deg
             transition from 0 # to +5 # from 330 deg to 350 deg
             +5 # from 350 deg to 20 deg
             transition from +5 # to 0 # from 20 deg to 40 deg
             0 # from 40 deg to 135 deg

  Assumptions: 35 pounds is a reasonable downward push for continuous riding.
		(is this true? What horse-power does this equal? .10 Hp is
		typical for recreational riders).
	       5 pounds is a typical light pressure on the pedal for bare
		pedal riding. (is this too much?)
	       5 pounds is O.K. for pulling up on cleats. (is this too much?)
               5 pounds is O.K. for the forward push at the top when wearing
                 cleats
              10 pounds is O.K. for the backward pull at the bottom when 
                 wearing cleats (the scraping the mud off motion)

    	Setting up a spreadsheet to calculate pedal efficiencies:

  Column A: manual input - angle in degrees, 0 to 355 at 5 deg increments
         B: sin(col A)
	 C: cos(col A)
	 D: vertical force - manual inputs
         E: horizontal force - manual inputs (blank except for cleats)
         F: col D * col B
         G: col E * col C     (blank except for cleats)
	 H: col F + col G     Sum col H at bottom of col (H74)


	Set up: row 1 = labels
		row 2 = 0 deg
		row 3 to 73  replicate cells in row 2 Relative
		H74 = sum col H


	Caution: watch signs of horizontal force in cleat case.

	Numbers at H74 for my inputs: bare pedal 663
				      toe clips  890
				      cleats    1087

	Have fun!  - Chris

    Veeeerrry interesting!
    
    I don't feel like arguing about the forces and angles you've decided
    on, as I can feel great waves of ignorance sweeping over me. However,
    why can't I push forward if I'm using toeclips but not cleats? I think
    I can. Also, do people really pull up on the pedal when using clips?
    I'm not saying they don't, just wondering. 
    
    When I went to using toeclips, my greatest benefit was the increased
    confidence that my feet would stay on the pedal. Up until then, my feet
    would occasionally come off if I made a bad gear-change, a few times
    with nearly disastrous results. But after two years of use, I still
    hate feeling for the pedal while I'm pulling away from traffic lights. 
    
    Rod

    
    	Just a coupla comments, no disagreement.
    
    1)	The weight of the rear leg somehow has to get from the bottom
    of the stroke to the top of its next stroke.  Whether this is done
    by lifting it with its own muscles or letting it rest on the pedal
    and having it pushed up by the other leg's downward force doesn't
    make much difference, i.e. net energy (perhaps I mean 'force', or
    'work' ?) requirement is the same regardless of the muscle group
    involved.  I think that beginners that are used to only/mostly walking
    tend to use all push down on the front foot; as they get into longer
    or harder rides that muscle group tires and they start to lift at
    least some of the rear leg's weight with its own muscle group, these
    are the  "new muscles I didn't even know I had"  that beginners
    don't seem to discover until they get beyond (I'd guess) ~15 mile
    rides.  Somewhen around the same time their endurance/stamina starts
    to build up too, so they build the general fitness base that enables
    them to last long enough to tire the front_leg_push_down muscle
    group.

    2)	I think that the heavily ribbed touring shoes can transmit as much
    fore & aft force as hard cleats, especially the ones that have what
    amounts to a hard rubber cleat moulded into the sole.

    3)	I don't know that I'm actually AWARE of pull back, pull up,
    push forward any more, though I SOMETIMES make a conscious effort
    and try to "think circles".  I know I pull up real hard on climbs,
    but that's another subject.
    
    	Reg    {ol' twin straps}
    

    I'm a big believer in toeclips and cleats, but I think you've
    overestimated their efficiency. I have some cheapo department store
    pedals I can put on my bike; I'll ride the Wayside Inn TT course with
    them and tennis shoes, and see what I get for a time. 
       
    MATT

    When I arrived at the Wayside Inn TT course last night, I knew that
    I wasn't going to set any personal records.  My racing wheels were
    in the shop, and it looked like it was going to rain.  I figured
    that it would be as good a time as any to test the toeclip efficiency
    theory.
    
    I pulled the Cateye clips and Christophe straps off of my beloved
    MKS RX-1 Race pedals, and slipped on a pair of running shoes for
    the race.  The sky kept getting darker.  By the time I started,
    there was a tremendous downpour.  It rained like crazy throughout
    the ride -- large pools of water collected on the road, and streams
    ran accross it in places.  I felt more like I was on a hydroplane 
    than on a bicycle.
    
    Riding without toeclips was difficult in the rain.  My feet kept
    wanting to slip off the pedals.  It was hard to spin, and even
    harder to feel comfortable on an out-of-the-saddle climb.  
    Nonetheless, I put in a respectable time: 23:55, for an average
    speed of 23.1 mph.  This compares with my best-ever time (in
    good weather, with toe clips) of 22:34, or 24.46 mph.  
    
    This means that the MAXIMUM speed loss due to not having toeclips,
    cleats, or straps was less than 6%.  If you compare my time
    last night with an "average" time I had over a course (about 22:55),
    the loss would be only 4% or less.  I think this is only fair,
    considering the weather -- I had to take the corners much slower
    than I usually do, and I had to brake in a couple of places where
    the standing water and cars presented problems.
    
    At 23 mph, a 6% speed difference translates into a much bigger
    power difference, but nothing like the 40% claimed in earlier
    calculations.  From the "seat of the pants", it felt like 10%
    or less.  
    
    So to conclude, I think that the performance advantages of toeclips
    are small.  That takes nothing away from them, however, since:
    
    o They make riding much more secure
    o They help spread the effort over more muscles
    o They provide performance advantages going up steep hills.
    
    MATT
    
    I think
    it's more reasonable to compare this time

    Ah, but have you included a factor for the heavy rain which would
    have improved your time?
    
    Rod

Re: .0, .1, .2, .6

The numbers I've heard and seen in use by experts say there is, overall, 
a gain of up to 30% in efficiency.  You will note that I didn't say
"power".  The real gain is in the amount of energy you expend from your
muscles' reserve, and that shows up in the ability to ride a century
when you'd have been worn out after a half-century without clips/cleats.
And the phrase is "up to" because no two riders will achieve the same
exact gain - everyone's riding style is different. 

I can't ride the stationary cycle exercisers we have in the Wellness 
Center here at ZKO.  My feet won't stay on the pedals, not even the ones
with straps over the tops of the feet.  So my wind trainer gets a lot of 
use in the winter.

Re: .3

Yes, people who are used to clips/cleats do pull up on the backstroke.
That was one of the things my first skilled partner/coach taught me.

- Dick