Conference noted::bicycle

    
    I measure the distance between adjacent bolts, speaking for the
    Rank Amateur contingent.
    
    As to Shimano vs. Campy cranksets, talk about asking for a lively
    debate! :-)
    
    The most *practical* differentiator between cranksets may be the
    Q factor.  The 105's arms are quite wide apart (maybe a full cm.
    farther apart than Campy Record).  (Narrow is regarded as good.)
    
    If it weren't for that, I would still choose Campy for the finish
    (the would 105's probably subtract a fraction of an mph per ride
    just psychologically from their appearance :-)).  I have two or
    three Chorus cranksets - they work fine.  Athena might be ok too,
    but I'd go with Chorus to be safe.  Campy is still reputed to be
    tops in the smooth-bearing department.
    
    -john

 The math to compute chainring bolt diameter from adjacent bolt center-to-
 center distance is:
 
 	chainring diameter = (distance_between_bolts) / sin 72�
 
  or    chainring diameter = (distance_between_bolts) / .9511
 

 Please note that the formula in the preceding is for five (5) arm spiders.
 

    
    I would think the chainring bolt diameter would be largely independent
    of how far apart the bolts are.  Certainly a standard bolt-size is used, 
    or?
    
    -john

    
    re: basenoter. The catalogs DO use method1.  On road bikes, 
    the rings have the same spacing.  On most mt. Bikes, 
    the large and middle rings have the same bolt spacing, the smaller 
    ring has a much shorter spacing. The spacing on the middle and large
    chainrings for a road bike is different from the spacing on the 
    middle and large chainrings of a mt. bike. I'm fairly sure that, 
    for a Sakae crankset, the spacing of bolts will match either the 
    standard road or mt. spacing. I have a Sakae crank on my 1987
    Cannondale road bike, but the chain ring bolts on this (double) crank
    have mtb spacing.
    I guess what I am saying is to measure the distance between two
    adjacent bolts on your current crank, and go to the bike shop 
    and measure the distance on chainrings and you should easily be
    able to figure out exactly what you need. 
    
    Doug
    

>On road bikes, the rings have the same spacing. 
    
    Would that life was so simple.  I do believe that various companies are
    beginning to conform to a standard.  I certainly have two sets of
    chainrings `Shimano-standard' and `Stronglight-circular' standard.  I
    have never owned any Mavic or Campi kit sdo I suspect that they
    traditionally also had standards......

	re:-2
	I know the bike catalogues use Method 1.  The shops seem to
	use method 2.  Or at least, 4 of the shops I talked to.

	My method 1 distance is 84.7.  The catalogues (and the one I
	measured in the stores) list the distance as 76.7mm (I think-
	I don't have the mags handy).   One shop I stopped at pulled
	out his trusty reference guide and said that my chainring
	was one of the 2 standard size available. HOWEVER, he only had the
	other size in stock.  He did have a used CAMPY ring but it was
	warped.  Another shop (Belmont Wheelworks) said that the size
	was the old Campy Nuovo Record size but they stillhad them available
	at $60 a ring.   Since a new crankset (complete with new rings)
	is also in this range, I thought it might be time to upgrade
	to the "latest" standard size.

	I do tend to like Campy but Shimano does seem to be more innovative. 
	
	My perfect solution to the problem is to buy a new bike but
	"It followed me home!" might stain my credability with my wife 8^)

    
    You aren't going to go wrong with either Campy or Shimano.  Just
    consider what *level* (model) you want to be at, and, again, consider
    the Q-factor (spread between the arms) of the model(s) you are looking
    at.  That's not a *quality* distinction but a design distinction.
    
    In terms of model: $60 to make a Super Record crank "whole" again
    seems to make better sense than $80 for a new 105 crankset.  The
    end result of the $60 will be a higher-quality crankset.  BTW, I forgot
    what you said you had, but the older cranks (such as Super Record)
    and today's higher-priced ones tend to be cold-forged, resulting in
    a stronger (and prettier) crank.  So if you have an old crank which
    is cold-forged, its quality will exceed the new non-pro-level cranks,
    at least in that respect.
    
    -john

    I would agree that the old super record cranks are high-quality,
    but doesn't aluminium weaken with age?  Even ignoring that, if you 
    have a 20-year-old Nuovo Record crank, wear could be a factor: the 
    arms have probably been tightened onto the spindle many, many times
    over the years.  It could have weakened, or cracked, or worn so that
    it doesn't fit perfectly.

	Thanks All!
	I talked to yet another shop yesterday (INTERNATIONAL)
	and they said that the 2 "standards" at present are
	110mm and 130mm (using Method 2).  My Sakae is 137mm.

	Is there a way to tell if the crankset is cold-forged?
	I haven't had any problems with the crank or bottom bracket
	since I had the bike.   In my above mentioned choices, I agree
	quality is not an issue both Campy and Shimano are good
	-but Campy looks nicer - which is important since the nicer
	it looks the faster it goes 8^)   Like having racing stripes
	on a car!

	John, you mentioned Chorus - I don't know much about Chorus components
	I had thought that Athena was the "newer and better" quality. Is
	this not so?

	I guess if they can't get a reasonablly priced ring (special-order)
	then I replace the present with either Chorus or Athena since Campy
	appears to have better bearings

    
    Cold forging: the way to tell whether the crank is cold-forged,
    I think, it to know, or to ask.  A knowledgeable bike shop should 
    be able to tell you, or eminent members of this conference.  Campy
    Record-level components have always been.  Athena may not be. Not sure.
    
    In general, cold forging lets you get by with less metal, so that's
    something to look for in the end result.  That's one reason many newer
    cranks and other components look so "beefy" - they are not cold forged,
    so have to use more metal to attain the same strength.
    
    The Campy road gruppos (gruppi di strada?) are (top to bottom)
    
            Record        ("professional")
            Croce D'Aune  (discontinued - not enough differentiation)
            Chorus
            Athena
    
    Below Athena, there was Xenon for a while, but it was just seen as
    too cheapo.  Athena did come out after Chorus, I believe, but that
    doesn't have any correlation with quality or technical advance.
    Pieces of each gruppo gets periodically updated, anyway.  For example,
    Ergopower and 8-speed cassettes have made their way to Chorus (right?).
    
    Talk to Campy-opinionated people if you're choosing between Chorus and
    Athena.  I have an Athena brakeset, but in general have opted for
    Chorus (much as I would opt for Ultegra/600 for price/performance
    in the Shimano line).  Since you're just thinking about cranks, ask
    about those - I've seen people pleased with either model.
    
    -john

 The 110 "standard" has a competitor in the Microdrive (I think it is 92
 mm).  Campagnolo, Suntour, Specialized and some of the US crank
 manufacturers are making cranks to the Microdrive dimension.  If you want
 some idea of how many sizes there are look at the chainring chart in
 Sutherland's Handbook.  

> The 110 "standard" has a competitor in the Microdrive (I think it is 92 mm).

From the Spring 1990 Nasbar catalog:

	Distance between adjacent holes (center to center):

		79.5mm		Campagnolo Athena, Chorus, and Record.

		76.4mm		Shimano 105, Ultegra, and DuraAce. 
				Sakae Edge.

		64.7mm		Shimano Deore, and Deore XT (outer and middle).
				Sakae SX Triple (outer and middle).

		43.5mm		Shimano Deore, and Deore XT (inner).
				Sakae SX Triple (inner).

 110 mm bolt ring diameter = 64.7 between two bolt centers on a five arm
 spider.
 92 mm bolt ring diameter = 54.1 mm between two bolt centers
 135 mm "    "    "       = 79.3 mm   "      "    "    "

 The number in .2 are wrong, you guys should have caught it.
 
 The real numbers are:
 
    chain-ring-bolt-ring-diameter = bolt-bolt-center / sin 36�
                "                        "             .5878
 For a five-arm spider.  The sine is half the angle between two holes.

    Gee, what ever happened to Sugino?  The Aero Tour crankset was pretty
    much the standard on mountain and touring bikes just a few years ago.
    Did they go out of business?  I have not seen or read about their
    products for about two years.
    
    Just wondering
    
    Mike  

    Replacement chainrings for the common sizes including 144, 135, and
    130 (bolt circle) are made by one or more of the following: Sakae, Sugino,
    Stronglight.    They can be had for $25 or so.   The last time I looked
    The Colorado Cyclist was still selling the 144 rings; that should solve
    your problem.    

"bolt circle"  "bolt center"
 -----------    ----------

  144 mm           ?            Campy Nuovo/Super Record, old Suntour 
                                Superbe Pro, some Stronglight,  and 
                                probably .0's crankset 

  135		79.5mm		Campagnolo Athena, Chorus, and Record.


  130		76.4mm		Shimano 105, Ultegra, and DuraAce. 
  				Sakae Edge.

  110		64.7mm		Shimano Deore, and Deore XT (outer and middle).
  				Sakae SX Triple (outer and middle).

   92             ?             ?

    ?		43.5mm		Shimano Deore, and Deore XT (inner).
				Sakae SX Triple (inner).

  bolt ring            bolt center           components
    92	                  54.1               Suntour Microdrive