Topic: CB750 F rear hub on 16" HD wheel

[andrewk]

Hi all-

Sorry if this is the appropriate forum...

I've got a 16x3.5 rim with a spoke kit and a standard K hub, that I've been planning on lacing up and putting on my bike (73 CB750).  However, I've recently acquired another front brake setup, and am going to install dual front brakes, and I am now thinking about the benefits of a rear disc.

I've done about as much googling as I can stand, and haven't found much information about using the disc brake hub with a 16 rim.  I know I'd need the swing arm too (or modify mine to fit) but I'm wondering about clearance, and if it's even worth messing with.

Plans for the bike are a hot-rod everyday rider, mostly stock, but I want and intend to get nasty in the corners with it, and that's why I'm posting here.

And while I'm starting a thread, is a 16 inch rim going to help handling (relative to the stock 18, or 17 if I get an F wheel), or is there a better option?  Suspension is one area where I don't have much knowledge.  I'm wanting to run a 140 rear tire if I can fit it, a 130 for sure.

Thanks for any help/advice-

Andrew

[Tugboat]

Actually, I think that's what's on my '76 750F and only recently realized that it wasn't stock. Explains why it sits about an inch shorter than it should I like the way it handles but don't know relative to a stock F bike. Highway rpm's may be a bit higher too.

I do know that you'd have to weld a master cylinder mount to your frame if you plan on running a disc in back on your K bike - search the forum for info on that.

[Rigid]

An "F" model rear rim will already have the disc brake rotor and the frame can be modified to include the brake caliper brace and mounts.  I would start with a "F" frame if it were my build but that may not be the easier option for you.

[fang]

A 130 tire definitely will fit, a 140 will be have a close clearance at the chain.
The 16" rim will not necessarily improve handling, but lots of people like it just because it looks so awesome.
Many people consider the stock rear disc on the "F" bikes to be too much rear brake for these bikes.  I am not certain, but it is likely that this will be accentuated with a smaller rim.  IF you choose to just stick with the drum your braking power probably will be just fine. 

I personally do not know what sort of clearance issues you might encounter with the 16" rim and the disc brake.  There might be caliper to spoke issues.  I have had two 16" Harely rims laced to CB750 hubs, and both were drum.  One ran a dual row chain, just because that also was supposed to be awesome.  I sold both on eBay. 

[andrewk]

Thanks for the reply guys-  I did some measuring at the shop on an F bike I'm working on, and it looks like it should lace up just fine-  Fang brings up a good point-  I'm certain a drum would suit my purposes just fine, but there's that desire to do trick little things like this- you all know how it is.  

I'm a big guy, and I like the idea of having "more brake" out back-  I'll have to juggle the idea around a bit yet.  I was thinking about using some rear sets that incorporate a rear master mount, but I can always weld a tab or bung into the frame for a mount if need be.

Rigid-  I'm familiar with most of the differences in F and K bikes, but what's your reasoning for starting with an F?  Just because it already is set up for rear disc?  I do have access to a 77 or 78 F frame... I think it's missing the rear master stuff though.

[Xnavylfr]

I know that the GL1000 has the same type setup for the rear DISC as the SOHC but on the left side. I had a Naked Wing with a 16" rear and you could NOT remove just the brake assy. to change pads , you had to remove the wheel and brake assy at the same time, same way with re-assembly. You might ask this question on www. HONDACHOPPER.com . a lot of the chopper freaks have used the rear disc setup but I don't know if they also used the 16" wheel.

Xnavylfr(CHUCK)