Topic: The bronze bushings (No luck)

[Retro Rocket]

Forum member Hondaman already does replacement bushes and also has a fitting service..

Mick

[BigBoi]

Forum member Hondaman already does replacement bushes and also has a fitting service..

Mick

Yeah, but he only offers the full servicing on the swingarm when you send it to him. He doesn't sell just the bushings. (I PM'd him yesterday)

[Retro Rocket]

Ah, ok.

Mick

[ekpent]

Have you checked here yet?  http://74.125.95.132/search?q=cache:kUs4A8g0qHQJ:www.m3racing.com/products/parts.html+cb750+swing+arm+bushings&cd=1&hl=en&ct=clnk&gl=us   WHOOPS SORRY SEE YOU HAVE   

[BigBoi]

To all those who are interested. Mark over at M3 racing stocks these without the flange as well. They're 50$...which is still cheaper than Honda's steel version.

[Simpson]

Is it hard to remove the steel bushing?

Do you just tap it out with some round stock metal?

[steam-powered man]

it's a steel composite that actually crumbles sort of when driven out.  i used a little heat first; figured different materials would heat up at different rates, thus breaking up the "marriage" between bushing and barrel after unknown miles and then sitting since 1988. 

but i should have used the search function first.  seems an easier method might be to first hacksaw a little section out, then drive out.

new OEM came in friday, so popped 'em into the freezer.  later, i heated up the swingarm and zoom in they went.  had to recess them just a bit, so used a socket.  good luck,
bobp

[coyotecowboy]

Ok, I've got a reasonable question.  Why not run the roller bearings?  Is there no way to use o-rings to seal them up?  My 81 Husqvarna 430 XC has roller bearings and there is literally no side to side movement in them, and that bike has led a rough life with much of it spent in the sand.  Would they get that much more abuse on a road bike?

[ANVkevin]

I would give Z1 a call. I've dealt with them a massive number of times for parts. They are always great at finding a solution. Might be able to get something from their source pretty quickly.

[MCRider]

Ok, I've got a reasonable question.  Why not run the roller bearings?  Is there no way to use o-rings to seal them up?  My 81 Husqvarna 430 XC has roller bearings and there is literally no side to side movement in them, and that bike has led a rough life with much of it spent in the sand.  Would they get that much more abuse on a road bike?

I think my HawkGT has rollers as well. But from an engineering standpoint seems a controversy on use. Caged rollers should be used on something that rotates fully around and doesn't bear the loads a swingarm does. Bushings used elsewise. A bushing will have a lot more surface area to do the work than a small diameter caged roller.

But as with everything in life, if someone thinks something else will work and is committed to it, they can likely make it work.

A fully sealed up environment like I'm assuming your Husky is, they may be fine.

On the CB750 I've heard the roller kits simply aren't up to it. Mostly from water penetration. So proper sealing would be critical.

Perhaps the diameter of the spindle is important...

Just thinking out loud.

[steam-powered man]

more info:

i had an '81 cb750c last year, and in the course of prepping the bike i found tapered roller bearings in the steering head and needle bearings in the swingarm.  both are OEM, and there was good sealing at each location.  the needles rested on a hardened inner sleeve, with zero side-play.  very nice and smooth system.
bobp

[coyotecowboy]

OK, just checked my Husky parts list, it has 2 bearings per side with o-rings on each end and a hardened sleeve that the rollers ride on that slides over the swingarm attaching bolt.  But the swingarm bolt is also the rear motor mount and the collars that the bearings go in are seperate, unlike a CB Honda.  Soooooo, it may really not be worth the trouble.

[Simpson]

I ordered a set of the bronze bushing from partsNmore this weekend. Hopefully they have some in stock this time.
I'm sure I'll find out soon.

[BigBoi]

I ordered a set of the bronze bushing from partsNmore this weekend. Hopefully they have some in stock this time.
I'm sure I'll find out soon.

They do. I should have put up a post...mine came in last week and I installed them using Hondaman's oven method. Worked excellent.

[Simpson]

They do. I should have put up a post...mine came in last week and I installed them using Hondaman's oven method. Worked excellent.

Awesome thanks! Otherwise I would be thinking about steel replacements.
Any comments on fit and finish? Are you satisfied?

[BigBoi]

They do. I should have put up a post...mine came in last week and I installed them using Hondaman's oven method. Worked excellent.

Awesome thanks! Otherwise I would be thinking about steel replacements.
Any comments on fit and finish? Are you satisfied?

Well...the bushings look great. They went in tight but manageable with a piece of wood and hammer. I didn't know quite how far to push them in but I'm not sure if it matters. There was no play once I put the collar and the swingarm installed doesn't show any either. I'm happy with them.

[Bluegreen]

I bought brass bushings on ebay thinking they were bronze. Well actually not thinking....Will these be ok?

[jesus freek]

For bushings [bronze] try these guys www.charlies-place.com they are in San Francisco Ca.   cheers 

[HondaMan]

Well...the bushings look great. They went in tight but manageable with a piece of wood and hammer. I didn't know quite how far to push them in but I'm not sure if it matters. There was no play once I put the collar and the swingarm installed doesn't show any either. I'm happy with them.

They must be recessed 0.200"-0.220". This sets the compression distance for the felt grease seals, so they seal against water from the outside. This 'compression distance' is the distance between the inside of the phenolic end caps and the face of the bushing inside. If too tight, it will grind up the felt: if too loose, it won't seal water out. 

Observations about Honda's steel bushings: on many arms where these were installed, the next go-around for bushings (which is about 5000-10000 miles later with those parts) will find that the arm has been quite distorted by those bushings. This is because of the pressure it will see from the rust (which happens from the absorption of water from the air, in most cases) and because the bushing is actually thicker and stronger than the swingarm tube itself. When the arm is heated and the bushing cooled far enough to get them together (with Honda's stock dimensions), the pressure inside the tube afterward is enormous, spreading teh tube where the bushing is sitting, but not at the outside ends. This makes the steel ones REAL hard to remove.
(and that's being as kind as I can be... ).
And, the outer ends of the swingarm then have to be honed or machined out to match the inner diameter before installing new bushings, or it will crush the new ones during press-in, and they end up loose inside: I ran across this about 3 years ago when I forgot to measure an arm at the outside edges, where someone had removed the steel ones and then sent the arm to me: I ruined the new bushings I had just made to fit inside because the outer end was 0.002" smaller than the bushing location. They just spun around in the tube once they were pressed to location. 

I'm still not clear on why Honda has done this, maybe never will figure it out. It's clear that the original phenolic and Zamac bushings were never strong enough, which led to poor lateral arm stiffness, but to change to a destructive powdered steel material is just not like them. Maybe it has been subcontracted, or something? 

[BigBoi]

Well...the bushings look great. They went in tight but manageable with a piece of wood and hammer. I didn't know quite how far to push them in but I'm not sure if it matters. There was no play once I put the collar and the swingarm installed doesn't show any either. I'm happy with them.

They must be recessed 0.200"-0.220". This sets the compression distance for the felt grease seals, so they seal against water from the outside. This 'compression distance' is the distance between the inside of the phenolic end caps and the face of the bushing inside. If too tight, it will grind up the felt: if too loose, it won't seal water out. 

Observations about Honda's steel bushings: on many arms where these were installed, the next go-around for bushings (which is about 5000-10000 miles later with those parts) will find that the arm has been quite distorted by those bushings. This is because of the pressure it will see from the rust (which happens from the absorption of water from the air, in most cases) and because the bushing is actually thicker and stronger than the swingarm tube itself. When the arm is heated and the bushing cooled far enough to get them together (with Honda's stock dimensions), the pressure inside the tube afterward is enormous, spreading teh tube where the bushing is sitting, but not at the outside ends. This makes the steel ones REAL hard to remove.
(and that's being as kind as I can be... ).
And, the outer ends of the swingarm then have to be honed or machined out to match the inner diameter before installing new bushings, or it will crush the new ones during press-in, and they end up loose inside: I ran across this about 3 years ago when I forgot to measure an arm at the outside edges, where someone had removed the steel ones and then sent the arm to me: I ruined the new bushings I had just made to fit inside because the outer end was 0.002" smaller than the bushing location. They just spun around in the tube once they were pressed to location. 

I'm still not clear on why Honda has done this, maybe never will figure it out. It's clear that the original phenolic and Zamac bushings were never strong enough, which led to poor lateral arm stiffness, but to change to a destructive powdered steel material is just not like them. Maybe it has been subcontracted, or something? 

What confused me is the lip they've put inside the swing arm. I can't understand why they would have done that. It does nothing but make people think that they should knock the bushings in until they reach the lip.

[Simpson]

Well...the bushings look great. They went in tight but manageable with a piece of wood and hammer. I didn't know quite how far to push them in but I'm not sure if it matters. There was no play once I put the collar and the swingarm installed doesn't show any either. I'm happy with them.

What is the oven method? Do you heat the swing arm in the oven and cool the bushings in the freezer?

How do you get the old ones out?
In the past I've beat them out with a hammer.

[BigBoi]

Well...the bushings look great. They went in tight but manageable with a piece of wood and hammer. I didn't know quite how far to push them in but I'm not sure if it matters. There was no play once I put the collar and the swingarm installed doesn't show any either. I'm happy with them.

What is the oven method? Do you heat the swing arm in the oven and cool the bushings in the freezer?

How do you get the old ones out?
In the past I've beat them out with a hammer.

Yes, have a look here:

http://www.sohc4.net/index.php?q=node/308

I got the old ones out using the hacksaw method. A quick search will show you how to do so.

[Simpson]

Hey Thanks! That will be a huge help.  
These things are a bear if you try to use brute force only.

Looks like I will be buying a hack saw this weekend.

[754]

If you have access to large taps, you may be able to tap end , probably pipe tap. then scew in plug or bolt...then press/pound it out that way.

[HondaMan]

Well...the bushings look great. They went in tight but manageable with a piece of wood and hammer. I didn't know quite how far to push them in but I'm not sure if it matters. There was no play once I put the collar and the swingarm installed doesn't show any either. I'm happy with them.

They must be recessed 0.200"-0.220". This sets the compression distance for the felt grease seals, so they seal against water from the outside. This 'compression distance' is the distance between the inside of the phenolic end caps and the face of the bushing inside. If too tight, it will grind up the felt: if too loose, it won't seal water out. 

Observations about Honda's steel bushings: on many arms where these were installed, the next go-around for bushings (which is about 5000-10000 miles later with those parts) will find that the arm has been quite distorted by those bushings. This is because of the pressure it will see from the rust (which happens from the absorption of water from the air, in most cases) and because the bushing is actually thicker and stronger than the swingarm tube itself. When the arm is heated and the bushing cooled far enough to get them together (with Honda's stock dimensions), the pressure inside the tube afterward is enormous, spreading teh tube where the bushing is sitting, but not at the outside ends. This makes the steel ones REAL hard to remove.
(and that's being as kind as I can be... ).
And, the outer ends of the swingarm then have to be honed or machined out to match the inner diameter before installing new bushings, or it will crush the new ones during press-in, and they end up loose inside: I ran across this about 3 years ago when I forgot to measure an arm at the outside edges, where someone had removed the steel ones and then sent the arm to me: I ruined the new bushings I had just made to fit inside because the outer end was 0.002" smaller than the bushing location. They just spun around in the tube once they were pressed to location. 

I'm still not clear on why Honda has done this, maybe never will figure it out. It's clear that the original phenolic and Zamac bushings were never strong enough, which led to poor lateral arm stiffness, but to change to a destructive powdered steel material is just not like them. Maybe it has been subcontracted, or something? 

What confused me is the lip they've put inside the swing arm. I can't understand why they would have done that. It does nothing but make people think that they should knock the bushings in until they reach the lip.

Yeah, that lip is 2" deep (50mm), and the K0 bushings were only 1.675" long, recessed .230", for a depth of 1.805" overall, while the collar bearing area was only 1.65" long. The K1 and later bushings grew to 1.75" long, same collar (!). When the (cheapened) flanged versions appeared on the K5 and later bikes (with one grease zerk in the center of the arm), their length was 1.775" overall, while the bearing area of the new collar grew to 2", which yields a bearing area of 1.775" on the 2" collar (of which only 0.75" could receive grease!). Go figure...    It almost seems like the collars were designed by one group and the swinagrm bearings by another, it's so weird.

I've designed (and made 6 prototypes) a new collar that will allow for almost 2" long bushings with a larger collar OD for improved performance while allowing higher torque on the frame rails from the cross bolt. But at this time, I think it's sort of like that commercial on TV:
"Why Formula 409? Because the world is not yet ready for Formula 410."