Sheldon Brown wrote:
> John Thompson wrote:
>>
>> >> Then I looked in my 60s vintage
>>>> Zeus catalog and found -- sure enough -- that Zeus offered PISTA rings
>>>> for both 1/8" and 3/32" chains way back then!
>> >> How the PISTA ring ended up on a double crank is still a mystery,
>> though.
>>
>> > Commonly used for pursuits.
>>
>> Ok. But what then is the difference between a road ring and a pista ring
>> when both are intended to use 3/32" chain? Why not just use regular
>> road rings for both road and pursuit purposes? That would help inventory
>> issues if nothing else.
> Are you sure they're the same BCD? Up until about 1967, Campagnolo used
> the 151 mm BCD for track stuff, 144 mm for road...
Yup. Same BCD. I have road, PISTA (3/32"), and PISTA (1/8") rings and they all fit the same BCD.
Curiously, the 3/32" "PISTA" ring is 54T and has a reinforcing web (like Campy NR rings); I have a 54T 1/8" PISTA ring without the internal web (like SR ring) and a 53T road ring without the internal web.
54T PISTA for 3/32" chain:
http://www.os2.dhs.org/
54T PISTA for 1/8" chain:
http://www.os2.dhs.org/
53T road ring:
http://www.os2.dhs.org/
> Zeus stuff was generally the "poor man's Campagnolo" using similar
> designs and specs...
To some extent, anyway. Zeus incorporated titanium and sealed bearings sooner and more extensively than Campy, and the cranks accommodated 36T rings (for which my legs are grateful) and could be had with pretty drillium (48/36 rings pictured):
http://www.os2.dhs.org/
--
John "I like it" (john@os2.dhs.org)
Appleton WI USA