What chain do I need?
08-16-18 | 03:28 PM
#1
Thread Starter
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Joined: Oct 2008
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From: Akron, OH
Bikes: 2008 Seven Axiom Steel, 1984 Colnago Nuovo Mexico, 2008 Cervelo P2C, 2000 Trek Multitrack 7200
What chain do I need?
I have an 1984 Colnago Nuovo Mexico road bike with a double Super Record chainring set and a six cog Shimano Dura Ace freewheel. I replaced the original chain with a Schram chain and I get some chain rub on the inside of the front derailleur cage when in cog 1 and cog 6. I can trim this out using the front derailleur shift lever, but it's kind of annoying. Is this a chain size problem and if so, what chain should I be using?
Tsapp
Tsapp
08-16-18 | 09:38 PM
#2
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From: Los Angeles
Bikes: 82 Medici, 85 Ironman, 2011 Richard Sachs
I don't think you can go swing from cog 1 to cog 6 without trimming a little. That you can go 1 to 5 is splendid. Some folk use a 9 speed (narrower on the outside) chain and swear they are the best. I like a HG71 chain.
08-17-18 | 12:09 AM
#3
Ride, Wrench, Swap, Race
Joined: Jan 2010
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From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
A 9-speed chain doesn't always play nice right off the bat with old-days chainring spacing, but I believe Shimano's 9s chain would have the best chance, since it still has the widest outer sideplate dimension relative to it's pin width.
I sometimes have to dress the bevel of the small ring's teeth with a file to make a narrower chain downshift reliably, by holding a long file stationary against the left side of the rotating chainring, which effectively moves the tips of the teeth slightly toward the adjacent big ring.
Having the rear end of the cage positioned ever so slightly outward toward the crankarm (check for clearance!) tends to improve clearance with the chain overall.
A very old derailer should afford decent clearance with even an 8s chain, which is much narrower than the standard-width chain from 40-50 years ago.
In many cases I insert the jaws of a duckbill plier between the front derailer cage plates, immediately under/behind the main bridge. This opens up the inside width just enough to clear the chain in all of the right shift lever's positions.
The handles of the plier nestle between rear wheel spokes as the handles are pulled apart SLIGHTLY.
I sometimes have to dress the bevel of the small ring's teeth with a file to make a narrower chain downshift reliably, by holding a long file stationary against the left side of the rotating chainring, which effectively moves the tips of the teeth slightly toward the adjacent big ring.
Having the rear end of the cage positioned ever so slightly outward toward the crankarm (check for clearance!) tends to improve clearance with the chain overall.
A very old derailer should afford decent clearance with even an 8s chain, which is much narrower than the standard-width chain from 40-50 years ago.
In many cases I insert the jaws of a duckbill plier between the front derailer cage plates, immediately under/behind the main bridge. This opens up the inside width just enough to clear the chain in all of the right shift lever's positions.
The handles of the plier nestle between rear wheel spokes as the handles are pulled apart SLIGHTLY.
Last edited by dddd; 08-17-18 at 12:16 AM.
