CHAINS

[RodneyCB750K1979]

I'm looking for some helpful advice from anyone who understands motorcycle chains.  I'm looking to replace the sprockets and chain on my '79 DOHC Limited Edition due to their condition.  The sprockets are a 15T and 41T.  Should I go smaller on the rear sprocket? I'm not sure of the chain size. The front sprocket is stamped "330-15".  I hear o-ring chains require less maintenance. What size chain do I need?  Some are converting to smaller chains. What type of chain connection is needed (endless, bratted pin, snap ring).   I drove the bike up and down the street a few times before starting my restoration. It seemed to have a good ratio.  So, I could stay with the same chain size and 15/41 sprocket sizes, but wanted other opinions.

[TOOLS1]

You have a 2.73 gear ratio (41/15=2.73) I would try to keep with that ratio since you are happy with it. However I would definitely switch to a 530 O-ring chain, and a snap clip type master link. Withe the snap clip you will not need any special tools to work on the chain, and it is plenty strong enough for a stock bike.
TOOLS

[sgtslag]

The O-rings hold grease inside the rollers, which extends the chain's life, dramatically.  The older, non-O-ring chains, require more frequent cleaning/degreasing, soaking in kerosene, followed by soaking them in heated motor oil, for an hour, or so, to impregnate them with lubricant throughout their inner parts.  Then you have to lubricate them, just like you do O-ring chains, every 300 miles.

O-ring chains last longer, require less maintenance and cleaning, and they are less 'dirty' to use.  All of that oil, on non-O-ring chains, attracts a lot of dirt, which grinds the chain up, over time, just like sandpaper.  O-ring chains will do the same, if you use a 'wet' lubricant, as opposed to a wax, or 'dry' lubricant.  With a chain soaked in oil, there is a lot of fling off, until it dries -- makes a mess of your back tire, swing arm, etc.  With a good, dry lubricant, applied frequently, an O-ring chain can last around 20,000 miles.  Non-O-ring chains will last 10,000 miles, roughly, if I remember correctly.

There are variations on the O-ring, such as X-ring, but they're high-performance parts, more suited to racing, than casual street riding, IMO.  Get a decent quality O-ring chain, and you will be fine.

The 630 chain is actually meant for heavier, more powerful bikes.  I don't know why Honda put the 630 on the '79 models, as earlier, and later models, all came with 530 chains -- connected to the same engine!  If you change to a 530 chain, you will need to change the sprockets to match.  No issues known in doing so, you will not snap the chain due to the engine overpowering it...  

The OEM chain was riveted together.  You can still get the tools to do this with a new chain, but it is around $100 for the tools.  With a master link set-up, you can remove the chain quite easily, no special tools needed -- and it is much less money, too.  You won't use that riveting tool very often (around every 20,000 miles, or so...), and it won't make a very good paper weight, either.    Cheers!