Author Topic: Primary chain adjustment  (Read 1866 times)

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LJRead

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on: July 07, 2008, 02:35:54 am
I spent some time in the Yahoo Enfield forum trying to get some definitive answers to primary chain adjustment (PCA).  I did a search of the topic in Yahoo and also got some advice from Pete Snidal.  The problem I was having is that it is possible to get the quarter inch slack suggested by pulling the chain down, but as Pete said, this is spring tension and not slack.  He suggested that I measure slack slack at about a half inch total from pushing chain up to letting it back down, without the force that would give  additional chain movement due to springiness in the chain.

Still not quite satisfied, yesterday I used a straightedge about eleven inches long and an eighth inch thick and laid it across the two sprockets, on top of the dual  chain.  The end of it rested against a pillar to the front of the front sprocket. The catenary, or amount of sag in the chain below this straight reference source  gives a close estimate of slack and I set it at a quarter inch, giving a total slack movement, up and down, of about the half inch that Pete suggested.  I call this the "catenary method of PC adjustment" and am satisfied that it gives a good result. It is then only necessary to use the kick start lever to move the chain about, making sure that there are no tight spots, in which case you would need to let out a little more slack.  My particular chain proved to have symmetrical slack all the way around.

Hope this helps those who may run into the same problem.

LJ


birdmove

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Reply #1 on: July 07, 2008, 06:27:54 am
   Sounds like a very good method to me.

    jon
Jon in Keaau, Hawaii


LJRead

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Reply #2 on: July 07, 2008, 07:34:14 pm
Posted the same info over on the Yahoo Enfield site and Pete Snidal gave some approval of the method along with encouraging us to get the feel of the chain when routinely inspecting it with the cover on.