A shy cog?
10-16-19, 08:10 AM
#1
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A shy cog?
Still making adjustments and changes a fair # of weeks after building up my Masi Gran Corsa (I like the new titanium railed seat and the Campy seat post, both bought from forum members and taking 200 grams off the weight compared to what I was using before).
Anyway, running into an odd problem I am having trouble diagnosing. For some reason, getting into the 4th cog is not easy, it will jump from 3rd to 5th or vice-versa; once in 4th, it will shift in either direction readily enough. To my eyes, the (used) freewheel seems fine. What should I be looking at?Background info: My first 6 speed freewheel, a Atom 77 Compact (13-14-16-18-21-24), brand new PC-870 chain, basically NIB Campagnolo Nuovo Record rear derailleur (Pat 71), Campagnolo Record cranks 53/42. Just had the hanger aligned, chainline looks good to me with 3rd cog in plane with inner chainring, 4th in plane with outer chainring.
Anyway, running into an odd problem I am having trouble diagnosing. For some reason, getting into the 4th cog is not easy, it will jump from 3rd to 5th or vice-versa; once in 4th, it will shift in either direction readily enough. To my eyes, the (used) freewheel seems fine. What should I be looking at?Background info: My first 6 speed freewheel, a Atom 77 Compact (13-14-16-18-21-24), brand new PC-870 chain, basically NIB Campagnolo Nuovo Record rear derailleur (Pat 71), Campagnolo Record cranks 53/42. Just had the hanger aligned, chainline looks good to me with 3rd cog in plane with inner chainring, 4th in plane with outer chainring.
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Larry:1958 Drysdale, 1961 Gitane Gran Sport, 1974 Zeus track, 1988 Masi Gran Corsa, 1974 Falcon, 1980 Palo Alto, 1973 Raleigh Gran Sport, 1974 Legnano. Susan: 1976 Windsor Profesional.
Larry:1958 Drysdale, 1961 Gitane Gran Sport, 1974 Zeus track, 1988 Masi Gran Corsa, 1974 Falcon, 1980 Palo Alto, 1973 Raleigh Gran Sport, 1974 Legnano. Susan: 1976 Windsor Profesional.
10-16-19, 10:37 AM
#2
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So it’s the 16 cog that is troublesome?
Assume you are using friction shifters of some kind.
42 x 16 would be a very commonly used default gear on level terrain. Maybe that cog is more worn than the others. I would try a different freewheel just to check, but if all the other shifts are crisp, it really sounds like the cog to me.
Assume you are using friction shifters of some kind.
42 x 16 would be a very commonly used default gear on level terrain. Maybe that cog is more worn than the others. I would try a different freewheel just to check, but if all the other shifts are crisp, it really sounds like the cog to me.
10-16-19, 11:09 AM
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At least with Suntour freewheels, I've had a couple with this exact problem. In both instances a single cog had been installed backwards, i.e. with the sharp-edged side facing inward.
On the Atom (and assuming the cog isn't one with an integral spacer), look for any sign of the one cog facing differently from it's neighbors.
Also, are all of the spacers appearing to be of the same thickness?
On the Atom (and assuming the cog isn't one with an integral spacer), look for any sign of the one cog facing differently from it's neighbors.
Also, are all of the spacers appearing to be of the same thickness?
10-16-19, 11:32 AM
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At least with Suntour freewheels, I've had a couple with this exact problem. In both instances a single cog had been installed backwards, i.e. with the sharp-edged side facing inward.
On the Atom (and assuming the cog isn't one with an integral spacer), look for any sign of the one cog facing differently from it's neighbors.
Also, are all of the spacers appearing to be of the same thickness?
On the Atom (and assuming the cog isn't one with an integral spacer), look for any sign of the one cog facing differently from it's neighbors.
Also, are all of the spacers appearing to be of the same thickness?
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Larry:1958 Drysdale, 1961 Gitane Gran Sport, 1974 Zeus track, 1988 Masi Gran Corsa, 1974 Falcon, 1980 Palo Alto, 1973 Raleigh Gran Sport, 1974 Legnano. Susan: 1976 Windsor Profesional.
Larry:1958 Drysdale, 1961 Gitane Gran Sport, 1974 Zeus track, 1988 Masi Gran Corsa, 1974 Falcon, 1980 Palo Alto, 1973 Raleigh Gran Sport, 1974 Legnano. Susan: 1976 Windsor Profesional.
