Conference noted::bicycle

    I have a DECalc spreadsheet for 10speed (maybe 15, I forget) gearing.
    Nothing fancy, but beats a pencil and paper.
    
    -Scott
    

    Setting up a triple crank on a relatively short wheelbase
    could cause some problems.  One bike that I set up a wide
    range on uses a 39/48 shimano crank and 12/14/16/18/21/26/32
    on the rear.  This 14 speed setup has worked really well for
    me with many midranged gears.  Some say the ultra 7 freewheel
    adds to the wear, but I have found only excessive wear on
    a couple of gears.  If you persue this, make sure you have
    6 speed spacing in the rear wheel and frame.
    
    steve fuller

    I too have a spread sheet calculator for half step, in digicalc.
    Can send you an image, or run if for you if you give me the starting
    points.
    
    	Reg
    

    re .0: 
    
    Your idea of a triple sounds eminently reasonable, especially for the
    terrain. I have an (almost) half-step triple Trek, 28/45/50, 13-28,
    originally bought for California. The triple really saves my knees, and
    lets me keep spinning. The bike came with Cyclone II derailleurs, but I
    traded them for a Mountech front and a Superbe Tech rear. I find the
    Mountech front shifts very nicely. The Superbe Tech has no trouble
    winding up the excess chain.
    
    --Dan 

re .2

I don't understand what you mean when you say that a triple crank on a small
wheelbase may cause problems; I understand that I would have to install
a new, bottom bracket with a longer axle -- is that what you mean?

Also, I've got standard 5-speed spacing between my dropouts, so Ultra-6
is as high as I can go. I see some wear, but it's not a problem.

My basic premise is that to get smaller chainwheels, I've got to buy a new
crankset, and if I'm going to do that it might as well be a triple...

    
    If a 42-34 isn't small enough a gear for you, then you have little
    choice but to go with a triple. It will shift a lot better, too.
    I hate to see anyone retire a Campy crank for a lesser triple, but
    them's the breaks.
    
    There are many ways to set up a triple to get the "sweet spot" in
    the range you want. Your setup is awfully close to a half-step.
    As long as your idea of the middle range lies within the range of
    the the half-step, it's ok. But when you go out of this range, there's
    going to be a gap between the granny and the middle ring.
    
    Think about this, a standard alpine setup (42-53,14-26 or 28) and
    a 28 tooth granny. That will give you the mid range you want, and
    the upper granny gears (28-18,28-20) are useable.

    
    14-16-18-20-23-26 or 14-16-18-20-24-28.            

    
    Food for thought.
    
    CdH
    
    

    What I was refering to was the length of the chainstay.  If it is
    less than 16 3/4", you could find the triple more bothersome to
    use than its worth because of chain aligment.  
    
    If you want to save your campy crank, Avocet makes a 41 tooth
    chainring.  You could then have your chainstay's spread by a
    framebuilder for a 6 speed axle to put an ultra 7 on.
    
    just something else to think about.
    
    

Avocet does make a 41 tooth chain ring that has the same bolt circle
as the Campy's but they also took a notch out of the end of each of
the spider arms to accomodate the chain.  Thus an Avocet 41 on an
unmodified Campy crank arm should hop, skip, or jump about 400 - 500
times a minute.

(I do not recommend modifying a Campy crank to look like an avocet.)

As for a "racer's view" of gearing, (like calling 42-53 x 14-28
"alpine gearing") with all due respect, I think a racer's view of the
mileage required to achieve the conditioning needed to use these
gears is somewhat more than 100 miles per week. (invitation to flames)

In other words, I heartily recommend a triple (50-45-28) to anyone who
is not into "no pain, no gain, grunt it out" mileage.  Avocet is an expensive
way to acheive this but the chainwheels are hard enough to withstand
tens of thousands of ham handed shifts.  Sugino has a number of cheaper
offerings, the chainrings are softer.  A good touch on the front deraileur
and the chainwheels should last a long time, I have seen many cases of
severely chewed front rings on Sugino AT's, however.

                                 -< re 54.7>-
    
Okay, now I understand. But between which two points does one meaure
the chainstay?

I suppose this is obvious to everybody else...    

    
    Put the rear wheel as far forward as you can realistically go in
    the rear drops. The chainstay length is the distance between the
    BB spindle center and the rear axle center.
    
    Re: -2 <no flame>
    
    I had no intention of promoting pain when suggesting that gearing.

    	This is how I reasoned it. Most of you use a large gear of 50-13,
    right? I suggested 53-14 (or 52-14) because it's close and will
    allow your freewheel spacing to be closer together when using a
    14 tooth top cog. I suggested a 42 tooth inner ring because it extends
    his now-lacking middle range DOWNWARD (ie. easier gears) in comparison
    to the standard 45 tooth. And then you can put on your 24, 26 or
    28 tooth granny for the stump pulling.
    
    	I simply was trying to suggest an alternative gear layout other
    than the half-step. The choice of the actual gears is up to the
    individual.
    
    CdH
    
        

    
    	re   "a racer's view"  I don't believe in pain either, but I
    sometimes believe that grannie gears are self fulfilling, i.e.
    the racers don't have them because they got strong enough to not
    need them by not having them...  and conversely, a good way to stay
    weak...  etc.

    	Reg	
    
    	53/43 12-17  
    

        (Well, I have to commute on it, hence the 43) 
    

    If this is too late, maybe it'll help someone else. 
    
    I've been doing some casual riding with a triple for almost two years.
    The setup is 52/40/28 and 14/15/16/18/21/26.  I didn't know much about
    triples when I got a new bike and asked for those gears, but it's
    worked out well.  If I ignore the granny, it's like a 12-speed, but I
    have a reserve.  At the end of last summer, I didn't need it even
    climbing Mt Wachusset.  My first ascent of Wachusset this year, I sure
    did need it, but only there.  It will sure be welcome when touring with
    30-60 lbs of ____. 

    The 26 cog is also like a reserve, real nice having close spaced high
    gears when I'm fresh, but real low gears when my strength is reduced to
    that of a couch potato. 

    Since I added the triple myself, I didn't think about the fact that the
    derailleur (sp?) can't take up the slack on the 28 with the 14-18 cogs.
    I really don't need those, but I plan to upgrade my derailleur
    sometime just for the convenience.
    
    Glen

    
    
    Re: -1
    
    	That's exactly the type of setup I was referring to in a previous
    reply.
    
    Glad it worked out for you, Glen.
    
    CdH
    
    

	i don't do much cycling these days.
	
	jack
	
	52/36 and 14-24

    I'm new to the technical side of biking (i.e. gearing, etc.) and have
    seen mentioned in numerous places warnings about not using the lowest
    gear ratio, (biggest freewheel, smallest chainring).  Something about
    it messing up your chain, gears, etc.
    
    Could someone please post an explaination of this for me, or point to
    a note if it's discussed elsewhere??
    
    Thanks,
    Brian
    

    re: -1
    
    	You might be referring to the damage you can do to your
    knees (and other parts of your anatomy) by not *spinning*
    at a high cadence since you are in a very high gear for
    the situation,e.g., climbing a hill with the chain on the
    *large* chainring instead of the small(er) one.  Or, you
    are referring to the mechanical problems of chain, ring and
    cog wear (strain) from crossing the chain in the transmission
    from pedal to rear wheel.  The rule for a standard 10, 12 or
    14 speed bike (2 chainrings and either 5, 6 or 7 cog freewheel)
    is to never cross the chain from the big wheel to the big cog
    or from the small wheel to the small cog as this puts to much 
    strain on the chain and cogs leading to rapid wear or breakage.
    If you suscribe to this theory your 12 speed just became a 10
    speed and so on.
    
    						_Jerry
    						_Jerry
    		

>    I'm new to the technical side of biking (i.e. gearing, etc.) and have
>    seen mentioned in numerous places warnings about not using the lowest
>    gear ratio, (biggest freewheel, smallest chainring).

    I think you mean big-to-big or small-to-small.

    There are two reasons to avoid it:

    1. It wears the parts faster.  The chain has to curve from the plane
       of the chainwheel to the plane of the cog.  The further the
       seperation, the more the wear (and drag).

    2. There is probably another combination that will give you about
       the same ratio but cause less wear.  Depending on your
       gearing setup, big-to-big might be the same ratio as small
       chainwheel to middle sized cog.

    -Jeff Bell

Jeff's statement is probably referring to what you have heard.

It is generally true that you should not use small/small or big/big
combinations, which crosses the chain it its sharpest angle. 

This restriction does NOT involve limiting you from using your 
lowest or highest gear ratios (often referred to in gear-inches).
That is big/small or small/big where the chain is relatively 
straight.

	~Mike