Topic: Loose Final driven flange on CB550

[Franky]

Hi guys

I have ridden my all original CB360T for some time and recently bought a CB550 as a project bike.

It's a lot of fun turning the bike into a semi cafe-racer and I have often looked up solutions to various problems in this awesome forum.

Well, now I've come across a problem with my rear wheel, or rather the 'Final driven flange' (#12 in the drawing). It's loose and it doesn't look right to me. I've attached a few images and uploaded a video here: http://www.franky.dk/cbriders/video/video.html

What's wrong ?

Thanks, Frank

[333]

I'd say you need new wheel dampers (#11 & #12).

[Franky]

Thanks for the quick reply :-)

OK. That's what i feared... Those #11's are seemingly hard to come by.

The 'teeth on the back of #12: Are they rubber or metal?

I guess I'll have to take it apart and have a look.

[Johnie]

Keep in mind you also have a bearing in that flange. May want to check that out too. After watching the video I think the dampers are toast.

[Franky]

Hello again guys

Well, made a tool, drilled the holes and the thing came apart easier than feared.

I think the dampers look pretty good, in fact everything looks OK too my non-expert eyes :-)

I'm wondering though, if the instability or looseness is caused by PO replacing the bearing and not pushing it in all the way. This could cause the retainer to sit too high and not be flush with the final driven flange (see pic without flange: the retainer is screwed all the way in). The gap would then leave room for the flange to be able to be loose?

OR is the problem completely different?

I'm at your mercy, oh experts...

[dave500]

even with the dampers removed ,the flange should not rock around once the ring nut is tight,the "spout" end of the hub might have worn by now,so even if you have the ring nut tight itll let the flange rock,its not been fully tightened and has worn its seating position away,you might be able to shim(space) it up somehow,or replace the hub.

[Franky]

I had another look, and that last theory of mine is no good.

I'll look into your suggestion Dave - thanks!

[Franky]

Made a makeshift spacer of an old bicycle-cog and once tightened, it actually seems to work!

Since its locked down, I expect that the dampening effect of the rubber dampeners is diminished, but it beats replacing the entire hub... for now at least :-)

Let me know if you think this is unsafe to ride...

[stevej]

This is exactly the problem I  found whilst having a new rear tyre fitted, the final drive flange rocks around and the back wheel makes a clacking sound when spun.On closer inspection It looked to me as if the replacement rubber shocks i bought a while back were too short and not filling the gap between hub and sprocket flange (they look identical to the ones in your pic.)I found some strong 1/4"approx.rubber matting cut it into four pieces that fit perfectly in the hub under the rubber shocks  Tightened down the bearing retainer using threadlock and bingo the whole section feels lovely and taut and the wheel spins silently.Will roadtest the bike in the morning when going to work.

[kweb]

I know it been almost a year on this topic but did this rubber matting resolve your problem? I am having the exact same issue on my 550 and have been beating my head on the wall trying to figure it out.

[Franky]

Just to let you guys know: My shimming solution has worked fine until now...

[dave500]

get an old "serpentine belt"from a car,thats one of those wide flat ones with ribs on one side,cut four small strips as long as each of the large drive damper rubbers and lay them on top of them,then assemble the flange down tight,itll compress those strips into the rubbers and be firm again.

[Franky]

Hi all

So it's been 6 years since my little hack-fix, but now I'm back at it again. Check out this video:

The damping rubbers seem to be fine, if anything just a tiny bit loose. What I'm worried about, is the play between the flange and the hub. It just seem to be a bit too much.

Is it supposed to be like that? Do you have any ideas for a fix or a quickfix?

[dave500]

yeah that looks like the ring nut was loose for a while maybe?,thats sloppy,id just do an ichiban fix and wrap some cut up beer can metal around it to take out some slack,that will work,heres how the serpentine belt fix goes.

[Deltarider]

You may have a look here: http://forums.sohc4.net/index.php/topic,150358.msg1715764.html#msg1715764

[nuwonder]

My rear main drive flange is worn too and it's sleeved so it won't wobble around too much, but I'm too in search for a new one. That seems the only fix for that kind of wear. Mines so worn it needs a additional spacer with the sleeve to stay in place.

Found one cheap from ebay last week but lost bidding to this other dude who took it home for 65 bucks. It sucked. For me, not for him

[crazypj]

even with the dampers removed ,the flange should not rock around once the ring nut is tight,the "spout" end of the hub might have worn by now,so even if you have the ring nut tight itll let the flange rock,its not been fully tightened and has worn its seating position away,you might be able to shim(space) it up somehow,or replace the hub.

I was going to say that
You need to check inner diameter and most likely have a tin 'shim bearing' made after everything is restored to parallel surfaces. I took pretty good care of mine but it still wore enough to be noticeable (even when high pressure grease was used.) It's  done 'only' 106,000 miles

[Franky]

Thanks for your answers. Very detailed stuff Deltarider, great! I think I'll see if I can machine something to fix the slack AND add a few strip of Dave500 HighTech ZipZap (tm) Rubber Strips.

[Franky]

Here are some detailed images of the situation (click for larger images)







As you can see, there is some uneven wear at the top of the flange, caused by the looseness of the assembly. I'm now looking into machining and shimming the thing, to make it nice and tight again. I'd like to hear your opnions about the following:

1. What should the clearance between the bearing retainer nut and the flange be. I'm guessing something like 0,5 mm or less. It should be just tight enough for the flange to be able to move back and forth in the direction of the wheel. This way the cush-drive will do it's job, as opposed to the nut being locked onto the flange (as i guess my previous bicycle-cog "fix" did!).

2. What about the clearance between the hub "axle" (the one that measure 78,22 mm) and the flange. I'm guessing it should be quite tight, but I can't really figure out  what would be appropriate.

3. Material of shims: I'm thinking steel? I imagine aluminum being too soft? That it would wear to quickly... on the other hand, witout excess movement in the assembly, aluminum might be just fine.

[dave500]

yeah its quite worn out,try getting a big washer style spacer made up?clean that fine thread really well.

[crazypj]

Better to have to outer and inner diameters turned or ground back to  'round' and have a THIN  bearing made ('H' doesn't always work on keyboard since grandson wrote 'War and Peace' one day, he was only 22 months at the time  )

Using a a large washer isn't a good idea as the outer part is designed to rotate slightly.
 Locking things solid puts a LOT more stress on chain and gearbox, the dampers in primary drive just ain't enough

[Franky]

Hi guys

This summer I had my flange fixed by my local machine-shop magician - check it out:







He machined the new press-in part, and machined the flange, to remove "the ovalness" and fit the new part.

Seems to work well!

[dave500]

bloody good job.

[DaveBarbier]

Yeah that looks really nice. Too bad you won’t see it.

[RAFster122s]

Logan is parting a 78 cb550 as he ran into major issues.  Maybe he could ship you the rear hub and backing plate at a reasonable cost??