Re: [CR]Inch pitch? and more on chains

(Example: Framebuilding:Restoration)

In-Reply-To: <20060124152241.40605.qmail@web51513.mail.yahoo.com>
References: <20060124152241.40605.qmail@web51513.mail.yahoo.com>
Date: Tue, 24 Jan 2006 12:49:04 -0500
To: sam lingo <frameteam2003@yahoo.com>, classicrendezvous@bikelist.org
From: "Sheldon Brown" <CaptBike@sheldonbrown.com>
Subject: Re: [CR]Inch pitch? and more on chains


sam lingo wrote:
>
>The teens era catalog I have call 1/2" chain the "English Chain"

I own (and love) a 1916 Mead Ranger. I also have a photocopy of the original catalogue.

The catalogue makes a big deal about the English 1/2" roller chain specced for this model, but the actual bike has 1" roller chain. The chainring pattern is identical to the one shown in the catalogue, so I'm sure the drivetrain was original. My interpretation is that British factories had more important things to do in 1916 than making bike parts for export...

http://sheldonbrown.com/ranger

It is my belief that 1" chain is inherently much more durable than 1/2" chain. Here's why:

With 1/2" chain, ever other roller pair is connected by inner or outer plates. As the chain wears, the "stretch" (which actually results from wear on the rivet/bushing interface) causes the effective pitch of the roller pairs connected by outer plates to increase.

It is well established that as a chain wears, the sprockets wear to accommodate the increased effective pitch. However, with 1/2" chain, only every other roller pair has this increased pitch, so, unless you have even numbered sprockets and pay attention to the phase relationship of the chain to the sprockets, there's a 50/50 chance that a given tooth will be encountering an in-pitch or out-of-pitch roller. This constant mismatch accelerates the wear of chain and sprockets in turn.

With 1" chain, each tooth is separated from the next by a complete chain link. As the chain wears a little bit the sprocket wears a little bit to match, and they grow old gracefully together. This is true of either block or "skip link" roller chain.

I like the ride of the 1" roller chain on my Mead Ranger. I also own an older Schwinn road Paramount, which came with 151 cranks. I got a great deal on a 26 tooth 151 chainring, and found some NOS block chain, so I set it up as a road fixie with block chain, but I must admit that I do _not_ like the feel of the block chain. It feels rough and "granular" to me compared with the mellow 1" roller chain on my Mead Ranger.

Currently the Paramount has yucky tubulars on it, and I have tended to avoid riding it for that reason as much as the chain issue. I plan to try it later on with some nice modern clinchers and the block chain...maybe I'll grow to like it, and maybe the drivetrain will smooth out once it's broken in...

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