1999 uc broken rear swing arm

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isp

New member
Flyer,

You are quite right to advise against drilling out the transmission when fitting a later swingarm. The recommended solution is to fit aftermarket bushings that go in the later swingarm but accept the smaller axle. There are three firms I know who sell them, Motorcycle Metal, True-Track and StaBo.

I actually adapted the True-Track bushings I already had fitted in my old swingarm (they are larger in diameter than the later ones, so could be machined down).

The new swingarm was introduced in 2002 and used up to 2007.
 
That 'is' a game changer and makes just buying a later swing arm and using bushings a much cleaner/easier way to go.

I've already got my blocks started and may still use them to ensure the new SA tube can't be squished if somebody goes "gorilla" on the axel nut, but a later SA with bushings makes more sense .....

Thanks for that info Graham.

P.S. Do you know if the rear wheel axel dia. changed from the 1999-2001 to the 2002-2006, and if so can the difference be safely handled with different bearings?
 
I should have taken a pic of the piece that goes inside, it fit the tube so the SA won't crush. But I like the idea that you are talking about. How far do they go in past the hole? Thanks for all the good info.

Toby
 
There were reports that indicated some of the cracking was possibly due to over tightened axel nuts crushing the SA tube.
I assume this has been taken care of with the newer SAs (assuming it was an actual problem).

How's that for mincing my words (makes them easier to eat later on)?

I'm thinking more and more though, that I may actually go with just a new SA (no block).
If the block is not needed with the new arms, then adding it may actually add and issue by making the block's ends a point of concentrated stress on the SA tube.
So ...... I probably shouldn't over-think this anymore, and just do as Graham has suggested with the newer SA and bushings.
 
I'm just a little suspicious of how a crack forms as straight as it seems in those pics...


Could some one else have cut/welded it together before? I see you have ground the end cap(?), did you happen to notice if it looked as if it had been welded back together there?
 
This has been a problem for a long time. We made aluminum blocks as axle adjusters as well as made spacers to spread out the load against the swing arm. My aluminum swing arm has no problems due to me machining the parts.

When the new swing arms/rear forks came out in 2002 for non-racing/weight reduction situations the newer swing arms work fine. I have one on my bagger. This is my own old swing arm on my 2000 bagger. I make Delrin bushings with SS inserts and they work really well to tighten up the rear steer. Use your own Pivot shaft and DIY instructions are on my site.
 
Well .... that has got to be either the tiniest hand in the world or the largest rear end ever put on a Harley!!

Thanks for the info, both here and on your site.

I'll go ahead and continue with my blocks, and add them to a new SA.
I'm using a rear link and am still undecided on what/who's rear bushings to go with.
I need to get a better feel for the varying reports regarding how well they work versus increased vibrations.
My gut tells me that the whole motor mount aftermarket thing is still a moving point, and no system is perfectly refined ........ yet.
But that's probably a subject for a different thread .........
 
Crok, I looked at it before when I put a new tire on the rear, no crack or weld. I was not surprized when I saw it, just glad to get it fixed & back on the road. It is nice to have the tools to do it. I wish I had a lath or a GNC at home or work, but do have a couple of friends that are machinists that have helped me out in the past.
 
I bought a Grizzly gear head Mill with a power table at auction for under $1K, from one the of Silicon Valley businesses that went out of business in '90's.

I also purchased a gear head, gap bed, lathe that would turn up to 20" in the gap and 40" between centers, but when I retired and moved from San Jose to the Sierras (just outside Yosemite) it was just too heavy to move at 1400 lbs, so I sold it thinking I could use a jawed chuck and/or rotary table on my mill to replace the lathe.
That has worked out fairly well for small parts, but I am looking for another lathe (smaller one though) like an Atlas or something.
I know a few friends that have the combo lathe/mill/drill units from Smitty and Harbor Freight/ N.T. and although they are not professional level tools, they can be a real help for a garage shop where a fellow (like me) mostly makes chips from otherwise perfectly good metal!

But I do really do use the heck out of my mill, and it has proven to be worth every penny I paid.........

If interested, just keep an eye on the local paper's/on-line classifieds for auctions like the above.
Although it's an unfortunate sign of the times .... very good equipment like that from "tool shop/maintenance" departments in non-tool/metal fab businesses, can be a good source for this type of equipment ...... at prices (and operating voltages) that garage hobbiests can use/afford.
 
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