Topic: Esoteric CB500/4 question

[Spark6]

Hey all, I asked this question over on dotheton.com, and it was suggested that I might find some good answers over here. I'm horrible at using the search function, so if I'm missing an obvious answer, I'm sorry for cluttering up your board!

I've got a CB500/4 project which was coming along quite nicely until it turned out that the cush drive in the rear wheel was rust-welded into the hub, meaning that I cannot replace the destroyed wheel bearings, or true the wheel. I even caved and took the wheel to a reputable shop, and they finally threw in the towel, charged me for as little as they could, and suggested I source a new wheel. In doing some research, I found that the CB500T has a different rear hub than the 500/4, and that got me thinking... does anyone know if they are interchangeable? If so, I'd just lace a CB500T hub (which seem to be far more plentiful than 500/4 hubs) onto my rim and call it a day... does anyone have any thoughts?

The guys on DTT pointed out that CB550 hubs are identical to CB500/4 hubs, but before I just replace a part that seems like it might be poorly designed, given the way its frozen up, I figured I'd see if I can use a simpler unit (no cush drive) from the 500T instead...

Thank in advance!

[calj737]

There's really nothing wrong with the design. It has some idiosyncrasies sure, but it's been very reliable (and widely used still) on many bikes. The problem is caused by neglect, then it becomes someone's problem to correct and maintain.

I'd think you could salvage that hub, but to do so, cut the spoke out and immerse the hub in an ultrasonic cleaner to loosen the rust and free the drive/et al. Then rebuild and maintain going forward. Else, discard and obtain a 550 hub as they are widely available but will still likely need service.

[Mo]

Also, my understanding that the clearance difference between the 550 and 500 would require a different sized spacer in order to fit properly.

[Spark6]

Oh, I didn't realize that the 550 and 500/4 hubs were different. (doh.) So I'd have to get some sort of spacer machined to get the chain to align properly/shim the 550 hub into the 500 swingarm?

I'm not sure where I'd find an ultrasonic cleaner (or even what that is!)... I always prefer to make old parts work again when its practical to do so, but that sounds like it might be slightly out of the scope of my little shop in the garage...

[calj737]

The wheel spacers are stock. His point was: use a 550 hub, use 550 spacers. 500 hub, use 500 spacers.

You may be able to take the hub to shop and have them hot tank it to get it loosened. Ultrasonic cleaner uses (guess what) ultra sonic frequency to agitate and tear at surfaces in a non-destructive way. Jeweler so use small ones to clean rings and precious items. There's a solvent/liquid bath used to assist with cleaning and as a conduit of the sound waves.

A local Harley shop may be better suited to assisting you with disassembly of that hub. Old school guys unlike many new Honda shops...

[Spark6]

Ahhh, now I'm with you - thanks for the clarification, I'll keep that in mind if I end up going the route of a 550 hub.

I'll have to unlace the hub from the rim when I get a chance, and see what my options are with any local shops. I suspected that was what an ultrasonic cleaner was, but wasn't sure.

I appreciate the help!

[bryanj]

Two points:--

(1) You have removed the L/H thread bearing retainer before attemting to get the sprocket hub out havent you?

(2) only the 550 hubs 77/78 are different all the 500/550K from 71 through 76 are identical

[dave500]

does the shop know these bikes have a left hand thread retainer?clockwise undoes it,once thats off these no way anyone with some skill couldnt get the cush drive apart no matter how gummed up/rusted/butched or otherwise stuffed.

[Mo]

The wheel spacers are stock. His point was: use a 550 hub, use 550 spacers. 500 hub, use 500 spacers.

This and what brianj said!

[dave500]

the early 550 hub is the same as the 500,the later 550 is different and uses different spacers and the brake plate aswell.