Topic: CB750 Hub questions

[Garage_guy_chris]

I am getting ready to polish and assemble wheels for my 74 CB750 but i have 2 rear hubs and 5 front hubs to choose from and i would like to avoid using the wrong hubs,  So i have a couple quick questions regarding CB750 hubs 

1. Are all rear hubs 69-78 the same? If not what are the differences and how can i tell them apart?

2. Are all front hubs 69-78 the same? If not what are the differences and how can i tell them apart? Im also aware the front hubs were used on other bikes than the 750 are there any other incorrect variations to be aware of?

3. Regarding the rear hubs they have these 4 lines of casting tabs in the center of the hub i wanted to know if removing these would compromise the strength i swear i have seen these removed and the centers polished smooth.

[754]

Yes i have seen them cut smooth.. Seem to work.
 First thing find a hub that is not worn, many are these days..

 I can do the turning if you cant find anyone to do it..

[Stev-o]

There were two different front hubs used on the 71-78, guessing they changed at '77. 

[martin99]

I would guess you could just cut/file those tabs out - but is anyone really going to notice?

[Vinhead1957]

Before



During



After



Okay to notice them

[Garage_guy_chris]

Only real reason to remove the tabs is to make cleaning up and polishing easier without the tabs there it can be cleaned up on a lathe with sand paper

Also regarding the front hubs are the early "sandcast" or KO hubs any different then the later K1-K6 or all they all the same?

i believe this picture sums up the front hubs the left one being 69-76 and the right 77-78?

[Stev-o]

Yes, my K8 has a front hub like the one on the right. 


Look here for sandcast front hub info.....


http://forums.sohc4.net/index.php?topic=80602.0

[754]

Front hub changed for 77/78
 Guys used to shave the hubs and chrome them for choppers, looked really good..

[Bodi]

I've taken those circumferential webs right off front hubs, i can't see any structural reason for them. The hub looks nice without them (to me, at least). I can imagine them giving some strength to the rear drum brake drum bore and haven't taken them off a rear drum hub. The crossways webs - I would take them off with no worries.

[martin99]

Before



During



After



Okay to notice them

Ok, you got me. Love it!

Lucky for me I've got comstars, or that'd be another thing on my to-do list!

[754]

Perhaps. I misunderstood, maybe he meant just the cross ribs. No problem to remove.
 I thought he meant all fins , like the pic.