i have a 1983 bianchi campione d'italia which i upgraded to a regina cx 12-21 freewheel around 1984.
probably had a regina oro chain at the time. rode the bike regularly for about 3 years. from 1987
through now, i rarely rode it, accumulating maybe 300 miles in all. if i remember correctly, near
the end of the period where i rode it consistently, the chain would occasionally skip when on the 17
tooth cog of the 12-21 freewheel. those first two years i averaged around 200-250 miles a week. i
think i had a sedisport chain on it, probably mid range all black.
a couple of months ago, i brought it out of retirement (i'm 36 and looking to lose weight).
almost immediately, i bought a sachs PC-58 chain. installed it with the same length. i was reminded
of that little problem when the skipping continued. strange thought i. well, maybe it's that
particular worn cog. so i bought a regina america 6 speed 13-22 freewheel which showed no wear to my
eye. surely that would solve the problem...
i installed it this past weekend and it still skips (the new sram chain probably had about 200 miles
with the old cx freewheel). the problem manifests itself by generally jumping to the next smaller
cog, but usually moves to riding along the top of that next cog first. it's very disconcerting. on
small climbs, and even now, just riding along on the flat at 15-20 mph without any unusual pressure
applied, it will jump. the especially disconcerting part is all of a sudden, it feels like i just
shifted into neutral of a car, with almost no resistance at all. i just start spinning like crazy.
a related issue is the newer downtube shift levers i also bought on ebay. they are the smooth
finished campy ones, probably mid to late 80s, with a small curve cut out at the end of the levers.
before i installed the friction levers, i managed to lose one of the washers. i mounted it anyway
and the lever for the front der. would move on it's own accord. i swiped an identical looking washer
from my original campy NR shift levers and it solved that problem about 95%. i still have to
occasionally check tightness. but i don't think that's the problem with the chain jumping to ride
the top of the next smaller cog. but i may be wrong.
anybody have any ideas what could be the problem? it's a 20 year old campagnolo nuovo record rear
derailleur. perhaps a tensioning spring has loosened over time?
help? i love this bike but i dread riding it now. i'm THIS close to taking it into an LBS... but i'd
love to do the work myself.
eric
fresno, ca.