Topic: Help! What size bearings?! 1976 CB750 F Henry Abe rear 16" rim

[Tugboat]

Long story short, I was having issues with my old rear wheel and decided to replace it with a NOS Henry Abe 16" wheel that is listed on the original box as being for a 75/76 750F. I figured that it would take the same bearings that the stock hub would; but no - the diameter of the hole they're supposed to go into is smaller than the bearings themselves. The bearings are All Balls, and are the 6304's that are supposedly correct for the stock Honda hub. Anyone know what size bearings these things use?!

[steam-powered man]

you can size the bearings by measuring the wheel bore, and width of bearing.  the bearing bore on ball bearings is the last 2 digits x 5. 

OD -- measure wheel bore
ID -- 4 x 5 = 20mm
width -- measure the bearing seat depth

for example a 6304 bearing has:
OD -- 52
ID -- 20
width -- 15

[lucky]

You need to buy a pair of vernier calipers and measure the hole.

[Tugboat]

Bore measures 51.9.. is that right? Is the bore always slightly smaller than the bearing?

[steam-powered man]

the supplied bearings might be correct, you need to measure depth of seating area to confirm.  to install you should warm the hub and freeze the bearings.  on this valuable wheel, i'd press the bearing in carefully, keeping the bearing exactly at 90 degrees to the bore.  is there a steel bearing seat cast into in the aluminum hub?

[Bankerdanny]

You need to buy a pair of vernier calipers and measure the hole.

What he says. You can get digital calipers at any chain auto parts store for about $20.