Should I heat treat ?

I have machined some replacement bushings for a motorcycle swing arm . The
inner sleeve is 4140 steel approx. 1" in diameter, there will be an ampco 18
bushing 1.6" long riding on it . This unit will see maybe 20 degrees
rotation in normal use . I was originally planning on hardening the inner
(steel) sleeve before final sizing . I do have a light duty toolpost
grinder , and can get the proper stones . I'm at .008" -.010" oversize now
for a .002 clearance fit .
I'm wondering if I need to harden them as originally planned ... or if a
nicely ground finish without hardening will give acceptable wear - I only
wanna do this once . I do have what I need to treat these , I'm just trying
to be lazy ...
Reply to
Snag
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How hard are the factory bushings?
Reply to
Tony
The factory bushings are a rubber/silicone/steel unit , designed to absorb vibration at the expense of handling . The early rubbermount Harley touring models have a history of high speed handling problems , partly due to the OEM swingarm pivot bushings . Aftermarket suppliers make something similar to what I'm doing , but they're real spendy . I could have spent nearly a thousand bucks on the mods I'm doing if I used their parts , materials have cost me less than a c-note ... I'm not in a great big hurry to finish these , won't be installing them until this winter when I tear the bike down for other items that also need attention .
Reply to
Snag
If it's your own bike and you know about the issue, why not do it the simple way and see if they wear excessively? I don't think it's necessary to design bearings for long lifetime if you keep them greased and can easily make replacements.
Comments, anyone?
jw
Reply to
Jim Wilkins
If these are replacing rubber bushings I don't see the need to heat treat. However you may want to consider polyurethane bushings as a replacement, like the off-roaders 4 wheelers use.
Tony
Reply to
Tony
These bushing assemblies attach the front of the swingarm (rear fork , to some) to the pivot shaft . This shaft attaches to the frame , and also supports the rear of the engine/transmission assembly . This is an 800 pound touring motorcycle ... and those composite bushing assemblies are quite a bit more complicated than a "rubber bushing" .
Reply to
Snag
How are they any different than the rubber bushings in automotive spring shackles, shock absorbers, sway bars?
Reply to
Tony
What you're making is similar to these, no?
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Those are delrin with high carbon steel sleeves. I didn't ask if they're heat treated, but I suspect so.
Actually, I just pinged Kevin there and will letcha know.
Snarl
Reply to
snarl
Actually , the ones I've made are as close to the OEM cleve block dimensions as I can get (a kind soul sent me some cad files ...wanna copy ?) . All the other small parts will still be used , including the compliance ring on the outside of the unit . I looked at the sta-bo and another , couldn't see from the pics where they allow rotation between the swingarm and the pivot bolt . The inner sleeve on these will be held captive between the tranny case and the outer rubber mounts , just as original . The outer shell will rotate with the swing arm . I haven't decided yet how I'm going to establish end play , I can either press precisely , or set tthe outer to a preset depth and shim the thrust faces . I got all the stuff together to heat these , and still can't decide if they really need it .
Reply to
Snag
Yes please... that from D-rog? Addy is: BS 37 at snarls hog den dot com. Remove th' spaces and change th' obvious.
Kevin got back to me and said they are heat treated. FWIW, I also asked him about longevity (100,000 miles) and he sent me this:
"Yes - the high carbon steel is heat treated. Yes - STA-BO I will last well over that mileage. The first STA-BO I we ever installed was on a 1986 FXRS with a 103 CID engine and currently has 300,000 miles on it and still going."
When I had that last belt replacement done, I asked 'em to check th' swing arm bushings whilest they're in there, and they said they were fine. Methinks th' cocksucker never even checked 'em since there's 140,000+ miles on 'em. So for this winter I'm gonna make a set Sta-bo style and we'll see if that helps... unless I go th' way you are.
I'll tell ya this much, as far as customer service goes, sta-bo answers questions post haste. You might wanna ping 'em about rotation between the swingarm and the pivot bolt.
Snarl
Reply to
snarl
snipped-for-privacy@tripod.net sezz:
Nope! That guy's a slacker...
Reply to
Doug
Well, yeah, but how big are those cad files, slacker?
Snarl
Reply to
snarl
snipped-for-privacy@tripod.net sezz:
I really don't have anything to do with those.
Reply to
Doug
I was plannin' on sending you (Snarl) a snail mail copy (cd or paper , no matter to me) , since you're on dial-up and the files are big . I'll include my notes from the stuff I've made ... Doug , you wanna copy too ? If so , ping me your snail mail address too and I'll make you copies too . Hit reply-to and change snagnone to snagone ...
Reply to
Snag
Snag sezz: Doug , you wanna
I sent you mail from an embarqmail.com address. -- Doug
Reply to
Doug
You've got mail.
Snarl
Reply to
snarl
$8.00 bucks and a pair of ice cold Coors? I might send ya some stuff this winter that needs yer talents.
Snarl
Reply to
snarl
snipped-for-privacy@tripod.net sezz:
What do I look like? A cheap, beer whore? Throw in a stinky cigar and I'm there!
I might send ya some stuff
You know how to find me. I'm in the very early stages of starting a little side business doing that kind of stuff too. You can be one of my "preferred clients"...
Reply to
Doug
Did you despam my email address ? I haven't received it yet ...
Reply to
Snag
Snag sezz:
Yessir. I'll try again... -- Doug
Reply to
Doug

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