Did Honda go to a larger chain for their 77 - 78 CB750 verses a smaller 560. Thanks, Dave {David, KY,USA 1977 Honda CB750K}

Chains do not come in size 560. I assume that this is a typo. Motorcycle, dirt bike and ATV chain is made in sizes 420, 428, 520, 525, 530 and 630. Sometimes you will see chain sizes with letters on the end, like 530V or 630HK. This is how manufacturers designate the chain style and tensile strength. For example a D.I.D. 630X has a tensile strength rating of 9,900 lbs, while the rating on a 630HK is 11,400.

In 1977 Honda increased the chain size on many of their bikes. Here is a list of all Honda CB750 bikes for 1975 through 1979 and their chain sizes.

Years	Bike	Chain
1976	CB750A Hondamatic	530x104
1977 & 1978	CB750A	630x88
1975 & 1976	CB750F Super Sport	530x102
1977 & 1978	CB750F	650x88
1979	CB750K Four	630x90
1975 & 1976	CB750K	530x100
1977 & 1978	CB750K	630x88