Another Vintage Campagnolo Question from the Masi Noob
02-21-21, 10:08 AM
#1
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Another Vintage Campagnolo Question from the Masi Noob
Hi All,
My 1982 Masi Gran Corsa project goes well, the replacement 6-speed 13-28 freewheel rides well, and bike is now in good riding condition. Hoping to ride in the California Eroica if that event takes place this year.
However, I have found the front 39 chainring has a bit of wear and will want to replace soon/eventually. The Campagnolo 53 and 39 135 BCD, 5-bolt arm chainrings currently on the bike (which I been told are 6 speed Chorus, yet to confirm) are stamped AS, and been unable to locate a replacement AS 39 chainring. However, there are several Campagnolo Record 39 chainrings NOS on eBay that are for 8/9/10 speed Record groupsets, pic attached. One seller stated that this Campagnolo Record 8/9/10 speed chainring has the correct 135 BCD and will work fine with with my 53 AS chainring 6-speed setup. My concern is that the 8/9/10 speed chainring will be thinner to accommodate the narrower 8/9/10 speed chains, and may not work correctly with my wider 6 speed chain.
Hopefully one of the Campy vintage experts here might be able to confirm if this chainring will work properly as a replacement for my current 39 AS chainring.
Hard to see in the pic, but next to stamped 39 is a stamped E in a diamond shaped outline.
Thanks in advance
My 1982 Masi Gran Corsa project goes well, the replacement 6-speed 13-28 freewheel rides well, and bike is now in good riding condition. Hoping to ride in the California Eroica if that event takes place this year.
However, I have found the front 39 chainring has a bit of wear and will want to replace soon/eventually. The Campagnolo 53 and 39 135 BCD, 5-bolt arm chainrings currently on the bike (which I been told are 6 speed Chorus, yet to confirm) are stamped AS, and been unable to locate a replacement AS 39 chainring. However, there are several Campagnolo Record 39 chainrings NOS on eBay that are for 8/9/10 speed Record groupsets, pic attached. One seller stated that this Campagnolo Record 8/9/10 speed chainring has the correct 135 BCD and will work fine with with my 53 AS chainring 6-speed setup. My concern is that the 8/9/10 speed chainring will be thinner to accommodate the narrower 8/9/10 speed chains, and may not work correctly with my wider 6 speed chain.
Hopefully one of the Campy vintage experts here might be able to confirm if this chainring will work properly as a replacement for my current 39 AS chainring.
Hard to see in the pic, but next to stamped 39 is a stamped E in a diamond shaped outline.
Thanks in advance
02-21-21, 11:16 AM
#2
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The 39 should be no problem.
the Big rig can be an issue as the Record crank has one chainring bolt that fastens from the back.
so, a different hole configuration there.
the subordinate groups have all exposed fasteners and assemble in the expected way.
the Big rig can be an issue as the Record crank has one chainring bolt that fastens from the back.
so, a different hole configuration there.
the subordinate groups have all exposed fasteners and assemble in the expected way.
02-21-21, 11:26 AM
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Very useful information to understand the compatibility you're facing: https://branfordbike.com/chainrings
02-21-21, 11:28 AM
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Your Masi is equipped with the original Chorus group from 1988 until it upgraded to 8spd Ergo in ‘92ish
I mix match 135 rings all the time on my Chorus cranks with no problems
I mix match 135 rings all the time on my Chorus cranks with no problems
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk
02-21-21, 01:23 PM
#5
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Hi
THANK YOU all very much for the info, most appreciated. Here is the pic of Masi. Beautiful warm day here in California's Silicon Valley, so I'm going to take the Masi out for ride along the bay..
THANK YOU all very much for the info, most appreciated. Here is the pic of Masi. Beautiful warm day here in California's Silicon Valley, so I'm going to take the Masi out for ride along the bay..
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02-21-21, 01:28 PM
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The perhaps-thinner teeth will work fine with 7-8s chain.
Campagnolo chainring spacing determination is "opposite" from Shimano's, in that Campagnolo's big ring is the determinant of chainring spacing differences.
That Masi looks great!
Campagnolo chainring spacing determination is "opposite" from Shimano's, in that Campagnolo's big ring is the determinant of chainring spacing differences.
That Masi looks great!
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02-21-21, 03:12 PM
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For your chainring wearing out, I would not worry about it too much. Campy chainrings have always been very long-lasting, in my experience!
02-21-21, 04:55 PM
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The spacing between chain plates has remained consistent, it’s the thickness of the plates that has reduced.
02-21-21, 05:01 PM
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Any 135BCD will fit (C) Record cranks, but the pin that stops the chain dropping between the crank arm and chainring may be in the wrong place unless it’s a Record chainring. Ideally it would also have the knurled nut that the hidden bolt screws in to, but you can secure it with a track nut and Loctite.
02-22-21, 10:55 AM
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Kinda, sorta, not really.
Any 135BCD will fit (C) Record cranks, but the pin that stops the chain dropping between the crank arm and chainring may be in the wrong place unless it’s a Record chainring. Ideally it would also have the knurled nut that the hidden bolt screws in to, but you can secure it with a track nut and Loctite.
Any 135BCD will fit (C) Record cranks, but the pin that stops the chain dropping between the crank arm and chainring may be in the wrong place unless it’s a Record chainring. Ideally it would also have the knurled nut that the hidden bolt screws in to, but you can secure it with a track nut and Loctite.
