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Hi Bwoltz,
Not yet, at the time I overhauled the pivot I just threw new parts at it and packed the works with Bel-Ray EP2 grease. The future plan is to find a alloy swing arm (Roaring Toyz) and fabricate the new pivot parts at that point.
Anytime I see a split bushing installed, the first thing that comes to mind is it's a cost saving measure, combined with the less than acceptable machine work of the "spacer" it runs on, the lack of weather protection, and lack of grease in my case, I'm surprised it went 20K miles.
My rough plan (subject to change at any moment) for the bearing is Ampco 25 with grease grooves, 4140 for the spacer (hardened RC 50+ than ground), about 2% of bearing ID for the clearances, and somewhere between 16 and 32 for the surface finishes. I will play with the diameters a bit to end up with a thicker wall bearing and use a light press fit with anti seize, and for the left hand side I will upgrade to a better equivalent size spherical bearing probably from Aurora bearings.
I would be very interested in your thoughts on this, I realize this is massive overkill but it should be fun to build .
: Mike
Mike.. What you've come up with will definitely work.. Like that swingarm.. Looks like most if it is CNC machined from bar and simply connected rectangular 6061. Very impressive what can be done today..
I will say I'm not sure it's all needed. I rebuilt the rear swingarm on my Dyna a little different.. Rebuild was done at 44000 miles but I'd repacked it once at about 20K. For 1 since I have an early model Dyna (2000) so the left side swingarm is a pair of timkins.. At 44K they were pretty much shot.. The problem with Timken bearing pairs is that they don't work well for partial rotation only.. They do much better spinning. The result is that the races wear in spots instead of evenly.. It's the nature of the beast.. I think the spherical bearings can work well but I haven't examined / used the newer other than the stock HD bagger ones. They seem to give up after a while.. I've examined the specs on the Aurora bearing some time ago and seem to remember that they were better than stock..
Your selection of hard bronze and hardened inner race is good. If going into an aluminum swing arm I'd make the bronze bearing as big as possible to support the load and keep it from elongating the aluminum. Not sure if that's a real issue tho..
When I rebuilt my swingarm, timkens were replaced as they are good except that they don't last (because of above). The split bronze bearing was tight in the swingarm, round and really didn't show any signs of wear. IIRC the inner sleeve was worn a little but if the unworn section was compared to the bronze bearing, the fit was too big something like about 0.010".. Since the bronze bushing was still round. I simply machined a new inner sleeve out of semi hardened 4140 or water hardening drill rod.. (Don'r remember which as I have both). I set the fit up to a 2-3 thou and put it back together.. It's got about 12K on it since the last rebuild and will probably get pulled and inspected in the tire change after next or maybe 2 more new tires.. I'll see how it looks then.. Right I've go 0 problems with handling on this bike.. I do think that HDs sloppy fit to start is what causes the right side swingarm bronze bearing setup to wear quickly.. The slop allows the inner sleeve to beat itself into the bronze. Proper fit and the bearing holds together much longer.
I've not had good luck with harder bronze and tighter fits. The harder stuff can gaul and seize. I'm a complete novice here tho..
What about using something like "Delrin" as it's self lubricating? Dunno if it would take the shock loads very well though.
Or, just drill & tap holes for zerk fittings on each side...
What about using something like "Delrin" as it's self lubricating? Dunno if it would take the shock loads very well though.
Or, just drill & tap holes for zerk fittings on each side...
Delrin has about 1/2 to 1/3 the stiffness of the more standard bearing bronze 932. IIRC it slipperier than bronze..
I've seen graphite impregnated nylon used for swingarm bearings in minibikes.. Delrin might be a little stiffer but it's easier to machine.
Mike.. What you've come up with will definitely work.. Like that swingarm.. Looks like most if it is CNC machined from bar and simply connected rectangular 6061. Very impressive what can be done today..
I will say I'm not sure it's all needed. I rebuilt the rear swingarm on my Dyna a little different.. Rebuild was done at 44000 miles but I'd repacked it once at about 20K. For 1 since I have an early model Dyna (2000) so the left side swingarm is a pair of timkins.. At 44K they were pretty much shot.. The problem with Timken bearing pairs is that they don't work well for partial rotation only.. They do much better spinning. The result is that the races wear in spots instead of evenly.. It's the nature of the beast.. I think the spherical bearings can work well but I haven't examined / used the newer other than the stock HD bagger ones. They seem to give up after a while.. I've examined the specs on the Aurora bearing some time ago and seem to remember that they were better than stock..
Your selection of hard bronze and hardened inner race is good. If going into an aluminum swing arm I'd make the bronze bearing as big as possible to support the load and keep it from elongating the aluminum. Not sure if that's a real issue tho..
When I rebuilt my swingarm, timkens were replaced as they are good except that they don't last (because of above). The split bronze bearing was tight in the swingarm, round and really didn't show any signs of wear. IIRC the inner sleeve was worn a little but if the unworn section was compared to the bronze bearing, the fit was too big something like about 0.010".. Since the bronze bushing was still round. I simply machined a new inner sleeve out of semi hardened 4140 or water hardening drill rod.. (Don'r remember which as I have both). I set the fit up to a 2-3 thou and put it back together.. It's got about 12K on it since the last rebuild and will probably get pulled and inspected in the tire change after next or maybe 2 more new tires.. I'll see how it looks then.. Right I've go 0 problems with handling on this bike.. I do think that HDs sloppy fit to start is what causes the right side swingarm bronze bearing setup to wear quickly.. The slop allows the inner sleeve to beat itself into the bronze. Proper fit and the bearing holds together much longer.
I've not had good luck with harder bronze and tighter fits. The harder stuff can gaul and seize. I'm a complete novice here tho..
Bruce
Hi Bowltz,
Thank you very much for taking the time, it's excellent information, and your views on galling are quite valuable. I agree the Ampco 18 is a better choice for this application. I have Ampco 25 cutoffs in my universal metal supply bucket but that doesn't mean I have to use it. Another noteworthy feature of Ampco 25 is the chemical composition is proprietary, so I can't make a guess on how sticky it is by how the material is alloyed. Time to rethink my material choices.
It's a shame Harley stopped using the spherical bearings on both sides. Even those were cheaped out, no seals so the ball would crud up and need cleaning occasionally, but they'd last a long time. I got new ones for my '04 at around 32,000 miles, had a slight amount of play, but when I got the new ones, they had the same slight amount, too. Sometimes I wonder if Harley engineers understand what "improvement" means.
It's a shame Harley stopped using the spherical bearings on both sides. Even those were cheaped out, no seals so the ball would crud up and need cleaning occasionally, but they'd last a long time. I got new ones for my '04 at around 32,000 miles, had a slight amount of play, but when I got the new ones, they had the same slight amount, too. Sometimes I wonder if Harley engineers understand what "improvement" means.
AFAIK they never made Dynas with 2 spherical bearings.. They've pretty much used the split ring bushing since the 90s.. Heck. HD only started using spherical ***** on baggers in 2002. I do think they used the ball type bearings on the softails since the beginning. 1984?
I just made a post about this.
Then I found this one.
What I'm looking for is to know if I can use bearings on both sides.
And if there is a better bearing that I can use.
And if so what's the make and part nimber.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.
) and fabricate the new pivot parts at that point. 
.
