Need Help Identifying Rims

[Haden]

Hello everyone,

I've got a 1976 CB750F with unknown, to me, rims on it. I've spent hours trying to figure out what they are exactly or what they come off of, but I can't figure it out. I'm curious if anyone on here recognizes them? The front wheel is 19 inches and the rear is 18. There's an adapter for the rear wheel that allows the rotor to be mounted and the sprocket just mounts directly to the rim. Everything else seems stock, like the tires sizes, axles, spacers, rotors, sprocket, etc.

I'm trying to replace the wheel bearings and the rear wheel has some piece, brass or some other soft material, holding one bearing in place. I don't know if it is pressed in there or on threads. I hit the bearing a lot from the inside and it didn't budge. I was hoping to figure out what the rims are so I could see how I'm supposed to get it out properly.

Rear Wheel and Rotor Adapter:

Rear Wheel Bearing :

Front Wheel :

 

[SenseAmidMadness]

What I can tell you is that the retaining ring over the rear wheel bearing is probably threaded. Several Honda CB models of the era, including my own 1980 K, use a threaded retaining ring that looks just like that. It's made of aluminum. I had a very nasty time removing it on my bike.
In your case, with how deep it is into that hub, making a custom tool to grab onto those two flat slots might be the best option. They usually thread out the normal counterclockwise way.
Probably the cheapest way would be buying a big impact socket that is a slip fit for the bore of that hub and grinding down the face so it has two exposed "teeth".

Those wheels look pretty special. Some boutique mag wheel manufacturer from back in the day would be my guess. I'm surprised they left no maker's marks anywhere but it's possible they only used decals back in the day, and of course those have disappeared.

 

[Haden]

Nice, that is some very helpful information. I'll have to figure something out to get a good grab on that ring and hope I don't strip it out. You're probably right about where the wheels come from as well, that makes the most sense to me. I wonder if there's any markings on the rim under the tire. I'm going to be changing the tires as well, so I'll keep an eye out and update the thread if I find anything.

 

[Haden]

Well, I was extremely unsuccessful at getting the retainer out. It is really in there. I got as good of a socket made as I could manage, gave it heat and penetrating oil, but it easily got stripped out. I then decided to drill and tap a couple holes to thread bolts into and try to pry off of. This probably would've worked if there was more width to the retainer. I could only safely get m4 bolts in it which easily bent when I tried to pry. I stepped up to m6 and they easily bent as well. With one of the m6 holes I drilled, I most likely took out the threads on the wheel with it. Maybe if I could get the retainer out, I could fix the threads or get them fixed, but I'm doubtful. I don't see any way this retainer is coming out without doing even more damage to the wheel. Any ideas?

As disappointing as it is, I think I've trashed these wheels. F0 and F1 rear wheels are basically non existent online from what I can tell so I might just be screwed. There are a few comstars out there from F2 and F3's, but I know the rear wheel on those are different so I'm unsure if they'd work.

 

[brettp]

Would it be an option to drill a metric sh** ton of holes in it and just breaking it apart? Or do you need it?

 

[SenseAmidMadness]

Would it be an option to drill a metric sh** ton of holes in it and just breaking it apart? Or do you need it?

This is not a bad idea, plus a chisel made for metal to deform it smaller

 

[Haden]

No, I don't think I need it. I don't have exact measurements of it so I kind of hoped I could get it out in a somewhat recognizable state. You're right though, I should just keep drilling holes in it and try to pry off some chunks of it.

 

[SenseAmidMadness]

From what I understand, that retainer is an extra-redundant safety feature that only Honda uses, and no Yamahas or Suzukis or Kawasakis from the era used anything similar.

 

[Haden]

Good news, I drilled a bunch more holes and was able to pry it out finally. Like I had thought, I did mess up some of the threads, but it actually doesn't look too bad and might be something I can repair myself. I need to explore my options.

That's good to know that it is probably a Honda OEM part. It looks like its the same part as part # 41231-300-020 which would make sense since that part is found on the stock wheel as well. I haven't been able to find measurements of it to make sure though. The one in my wheel was 52mm O.D and 40mm I.D. I don't have proper thread gauges, but it seems around 3.0 or 3.25.

 

[Haden]

Thread pitch is 1.5mm, I'm dumb

 

[SenseAmidMadness]

That does look salvageable to my eye. Some careful work with files and sandpaper would probably take care of it.

 

[Travis]

Good work getting that out. Get some thread restoring files and they should clean up pretty easily.

 

[SenseAmidMadness]

Or buy an M52 x 1.5mm tap

 

[Travis]

Be sure to look for a bottoming tap. Or chuck that wheel up in a lathe.

 

[Qaxe]

Those are the coolest of cool. I generally like spokes, but holy crap.

 

[Haden]

They are pretty cool, I'm starting to realize how special they might be. I was able to source a m52 x 1.5mm tap for cheap so I should be able to fix those threads properly. Once I get that sorted, I'll get those tires off and see if there any markings on the wheels to hopefully figure out exactly what they are.