Date: Mon, 23 Jan 2006 15:35:11 +0000 From: j.mccoin@comcast.net To: classicrendezvous@bikelist.org Subject: [CR] Inch pitch?
Greetings, this answer is probably way too esoteric, but I've just had my first coffee so here goes. That type of chain, also known as block chain goes back to the 18th century, possibly earlier, some early trucks and automobiles used a chain as part of the connection from the transmission to the rear wheels. It's only natural that it was used on bicycles, how else you gona do it. As manufacturing and the want to have more gears evolved the half inch pitch evolved, easier to go up and down a freewheel.
Oscar Juner always said that half inch pitch chain did not belong on the track, not strong enough, although I did break one in a sprint.
Take care
Jim McCoin Fremont Ca.
Hi Jim: Block chain is a type of chain, not a size, FWIW. The typical block chain for bicycles has solid inner links that are literally machined from a block of steel, hence the name. Block chains were eventually replaced by the roller chain (which, if I recall correctly was invented by Renolds in England, not sure of the specific year - Hilary or others in the UK may know). Inch-pitch is a size of chain - they are 1" in pitch (funny enough) by 3/16" in width, typically. But one pitch does not consist of two half-inch sections like on a half-inch chain. Rather, it consists of an inner section that is .400" long and an outer that is .600" long. Inch-pitch chains and their corresponding chainwheels and rear sprockets are quite stiff and responsive, due primarily to the additional width over a 1/8" wide setup. Inch-pitch track drivetrains were still widely used up to perhaps 1970 or so. Some still use them today on the track, although I would imagine that it's pretty rare now to see a bike with inch-pitch out on the track. Trackies, what's the scoop on that? Greg Parker Dexter, Michigan http://www.bicycleclassics.com