Re: HOW many teeth? 15/38 or 15/48?

Posted by Ooldskuul on Oct 06, 2012; 7:07am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/HOW-many-teeth-15-38-or-15-48-tp4030093p4030418.html

rich wrote

I converted my 79K from 630 to 530 also.

I used this handy online catalog to determine the stock sizes for an 80 750K - http://www.jtsprockets.com/catalogue/model/4841. They also have a gear ratio chart at http://www.jtsprockets.com/fileadmin/files/jtgearratio.pdf 

What I like is that it also gives the chain length. I went with 18/46 (same as stock 80) and my RPMs seem about the same as they were with the 630 chain with 15/38 sprockets. Due to the chain pitch, the sprockets are almost exactly the same size (e.g a 15 tooth 630 sprocket is the about the same diameter as an 18 tooth 530). Also, keep in mind if you're going with an o-ring chain that they are a little wider and you could run into interference problems if you go larger on the counter-shaft sprocket.

The DOHC has wide power-band. If you want to be "on the pipe" in the twistys, just drop her down to 4th. That way you can keep your 5th gear RPM low (relatively) for the occasional 70MPH freeway runs.

With the stock set-up (1980-82 18/16 630 pitch) and an o-ring chain, everything fit perfectly and installation was a breeze. The only issue I ran into was the chain I ended up came with a riveted master-link so I had to hunt down a standard clip link for it because I didn't want to drop another $80 for a riveting tool.

Sorry to be so long getting back to you Rich.  Both of those websites are good.  One of the few that have the numbers correct.  On the '79 model  the JI gear ratio chart says if I convert to a 530 chain, I should use an 18/38 to maintain stock RPM.   currently...I would still like to try a different ratio.  If I try the 19 tooth from Cycle X (Yes-I will check fit first) that would be quite a change.  I like that.  Or...If I dropped to a 36 rear...I Also like ....But NOT both of course.  If I don't like the ratio's, all I have to do is change a sprocket & I'm off and running.
What's a 70MPH freeway run?