Hey guys,
Thanks for responding. I decided to follow up some more as my vague
memory of the topic needed refreshing. Of course, google led me to our
man Sheldon's excellent resource ..... snipped from his page
http://www.sheldonbrown.com/
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ISO vs J.I.S. Standard Martin Trautmann posted on rec.bicycles.tech: L_right = 18 +0.5/-0 mm L_left = 16 +0.5/-0 mm Dimension across flat 1.5mm from end: 12.6mm +0.02-0.05 Spindle end to bolt seat: Loose: 3mm Tightened: 1.5mm min.
Yet another source claimed that the squares of Campa, Mavic and Stronglight (ISO) are smaller than Shimano and Suntour (JIS) with the result that JIS cranks will move about 4.5 mm further in.
This may conflict with the end of the square and result in a loose fit or braking stress. for ISO cranks on JIS squares there's less contact area between crank and spindle, since the crank does not slip perfectly on the spindle. The result again is a higher risk of braking the crank.
But assuming those 4.5 mm and 2 deg, ISO is about 0.3 mm smaller than JIS (2 * sin 2 * 4.5 = 0.3)? ISO cranks (Campagnolo, Stronglight, others) won't go as far onto J.I.S. spindles as they ideally should.
J.I.S. cranks (most Japanese models) may bottom out if installed on ISO spindles.
In practice, you can very often get away with mixing these sizes, as long as you select an axle length that gives the desired chainline.
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So, without further ado I'll out the campy crankset ebay auction that had me post my questions with regard to the topic. Im no longer interested, so have at it if you wish/dare/care ;) (no relation etc etc)
ah ... me still WTB a 170mm early chorus (or close) left hand crank, user. ;)
Yo Scott D !!!!!!!! What is a good readily available combo for fitting into old Campy/Fb 3 piece bare hub shells with regard to axles/bearings/cones ???
ciao, Ben Kamenjas Bondi, Sydney, Oz
> Scott Davis wrote:
>
> I think it's just a simple lack of standardization, not a JIS issue.
> As afar as I know, Japanese Industrial Standard JIS does NOT apply to
> Japanese BBs. I believe JIS applies only to headsets on bicycles.
> According to Sutherland's, JIS headsets are the same threading as ISO,
> BUT the crown race has the larger 27.0 mm diameter instead of 26.4 mm
> and the head tube cups are 30.0 mm instead 30.2 mm. JIS headsets are
> standard equipment on Japanese Keirin bikes. All parts on these bikes
> must be NJS certified for racing on the Keirin tracks in Japan.
>
>
>
> Jerry Moos wrote:
> Most high end Japanese BB's were not JIS. JIS was used on mid to low
> end stuff, of which Sugino Maxy was typical. The Sugino Mighty BB was
> a
> Campy clone. I think that might also have been true of early Dura Ace,
> although I believe the later Dura Ace BBs may have been sort of unique,
> neither Campy clones nor JIS. I also seem to recall that when
> Rivendell was selling some late Superbe cranks they stated that they
> took a
> special BB, although by that time, the Campy NR BB was long out of
> production, so an NR clone at that point might have been viewed as
> "special".
>
> Ben Kamenjas wrote:
>
>
> Maybe it's just an Aussie thing but most every used campagnolo crankset
> i've been looking to buy down here has been used with a shimano (or
> another brand) bottom bracket. Knowing that the tapers are different
> I'm wary of buying such cranks that may have been defiled. So ....
> what gives with mixing JIS with ISO and am I right to get all preachy
> with these neanderthals who are corrupting otherwise good cranks? Or is
> there no issue and they are OK to use? This matters most to me because
> Im thinking of track cranks and am hoping I'll have the right (or
> proper spec.) chainline.
>
> oh yeah, speaking of cranks ..... WTB - an early chorus 170mm left
> crank arm. croce d'aune is a maybe, prefer visually challenged (meaning
> cheap) for my early 60's aussie built sport-touring grocery bike. OK OK
> .... the only groceries I'm buying is beer, but doesn't that make the
> bike even more crucial to my well being? Just want a mate for the
> right hand chorus orphan I have ...... lemme know if you have sumtin'