Author Topic: Swing arm bearings  (Read 682 times)

0 Members and 1 Guest are viewing this topic.

Offline Czakky

  • Supporter
  • Fully Ported
  • *
  • Posts: 645
  • 71’R5 RD350 top end Supertuned
    • USA
    • View Profile
Swing arm bearings
« on: November 30, 2019, 03:41:57 PM »
I cannot feel any play out of my swing arm, I know that most Yamaha 2t twins get there swingarm bearings replaced with the bronze bushings.

I’ve always thought my old R5 handles pretty damn good for what it is.

How do you guys determine when these bearings need to be replaced?

Offline Organicjedi

  • Supporter
  • Stage 2
  • *
  • Posts: 391
    • View Profile
Re: Swing arm bearings
« Reply #1 on: November 30, 2019, 03:55:16 PM »
You'll get side to side play.

I can't imagine any of the original nylon ones are still holding up.

Offline Czakky

  • Supporter
  • Fully Ported
  • *
  • Posts: 645
  • 71’R5 RD350 top end Supertuned
    • USA
    • View Profile
Re: Swing arm bearings
« Reply #2 on: November 19, 2020, 08:33:06 PM »
I finally got around to this. I wish I didn’t! Got the bushings pressed in. Now the little stubs won’t fit.
Should I get the bushings machined? It’s like .2mm off. :bang:

Offline Dvsrd

  • Stage 2
  • *
  • Posts: 481
    • View Profile
Re: Swing arm bearings
« Reply #3 on: November 19, 2020, 09:01:35 PM »
I finally got around to this. I wish I didn’t! Got the bushings pressed in. Now the little stubs won’t fit.
Should I get the bushings machined? It’s like .2mm off. :bang:
If the bushings are fully seated in the swing arm, a long reamer, preferable with a pilot at the other end is an exellent tool to correct the inside diameter. I am sure it can also be done in a good pillar drill, or a milling machine.

Offline rodneya

  • Fully Ported
  • *
  • Posts: 536
    • Canada
    • View Profile
Re: Swing arm bearings
« Reply #4 on: November 19, 2020, 10:02:05 PM »
Needle roller bearings are the way to go.

Offline Yamaha 179

  • 2nd Gear Wheelie
  • *
  • Posts: 130
    • View Profile
Re: Swing arm bearings
« Reply #5 on: November 20, 2020, 07:29:30 AM »
I finally got around to this. I wish I didn’t! Got the bushings pressed in. Now the little stubs won’t fit.
Should I get the bushings machined? It’s like .2mm off. :bang:
If the bushings are fully seated in the swing arm, a long reamer, preferable with a pilot at the other end is an exellent tool to correct the inside diameter. I am sure it can also be done in a good pillar drill, or a milling machine.
I always used an automotive brake wheel cylinder hone to relieve the clearance problem.  It doesn't need to be precise, just a good snug fit between the bronze bushing and the steel sleeve.  I used an electric drill and probably cutting oil as a lubricant but that was years ago and I can't be sure about that. 
Lyn Garland

Offline Evans Ward

  • Supporter
  • Stage 2
  • *
  • Posts: 333
    • View Profile
Re: Swing arm bearings
« Reply #6 on: November 20, 2020, 07:37:26 AM »
Needle roller bearings are the way to go.

+1
I’m in the process of converting all my bikes to needle roller bearing swingarms at the present. I’ll get the swingers powder coated after installation of the bearings and some taped threaded rod with appropriate washers/ nuts to seal up the business internals.
1984 Yamaha RZ350
1976 Suzuki GT750
1972 Kawasaki H2 750 Mach IV

Offline Czakky

  • Supporter
  • Fully Ported
  • *
  • Posts: 645
  • 71’R5 RD350 top end Supertuned
    • USA
    • View Profile
Re: Swing arm bearings
« Reply #7 on: November 20, 2020, 09:48:46 AM »
Thanks lyn. I’ll see what I can find for tiny hones.

Needle bearings would be sweet, but I just need to get this thing back together. I need the space for a 900cc bevel head in my shed.

Offline m in sc

  • Breaking shit and taking names
  • Administrator
  • Super Stroker
  • *
  • Posts: 2610
    • View Profile
Re: Swing arm bearings
« Reply #8 on: November 20, 2020, 09:57:15 AM »
tbh, bronze bushings will provide more support but be mildly less responsive. Ive never had an issue with good bronze bushings.

why do they provide more support? more contact area.  But bearings are sexy.  anythings better than the factory plastic sleeves.

Offline Czakky

  • Supporter
  • Fully Ported
  • *
  • Posts: 645
  • 71’R5 RD350 top end Supertuned
    • USA
    • View Profile
Re: Swing arm bearings
« Reply #9 on: November 20, 2020, 10:03:45 AM »
7/8” brake hone on its way. I never knew such a thing existed. This place is awesome! :patriot:

Offline rodneya

  • Fully Ported
  • *
  • Posts: 536
    • Canada
    • View Profile
Re: Swing arm bearings
« Reply #10 on: November 20, 2020, 10:22:08 AM »
tbh, bronze bushings will provide more support but be mildly less responsive. Ive never had an issue with good bronze bushings.

why do they provide more support? more contact area.  But bearings are sexy.  anythings better than the factory plastic sleeves.

Bearings are also easier to install

Offline Czakky

  • Supporter
  • Fully Ported
  • *
  • Posts: 645
  • 71’R5 RD350 top end Supertuned
    • USA
    • View Profile
Re: Swing arm bearings
« Reply #11 on: November 20, 2020, 10:29:11 AM »
These days I need supportive over sex appeal though... ;D

Online sav0r

  • Stage 2
  • *
  • Posts: 343
    • View Profile
    • CL MotoTech
Re: Swing arm bearings
« Reply #12 on: November 20, 2020, 01:29:02 PM »
The needles see way more load to have the same tolerance as a plain bushing.

I’d think larger bearings would be required to generate much if any loss of friction.
www.chrislivengood.net - for my projects and musings.