Steel to aluminum swingarm conversion?????

Now that I have finished with my SBK fork conversion on my 97 900ss CR, it's time for the next project. I plan to swap out the stock steel swingarm with a aluminum one that came off a 95 SP that I picked up on ebay a couple of weeks ago. My questions for those who might know are, is there anything I need to know to complete the conversion and will the chain gaurd and guide from the steel swingarm fit on the aluminum one?

azccj -

How much did you pay for the swingarm ?

I'll be interested to see what responses you get as I've been thinking about doing the same. ( Actually I've finished my fork upgrade and can't stand just walking by it every day and not do something to it... )

I think they call that a 'Mental' illness...

I paid about 183.00 plus shipping and was quite please when it arrived since it wasn't all beat up and looks straight.

I put an aluminum swing arm on my CR and it was a straight bolt on installation. However the cast aluminum pivots were cracked and major surgery was performed to make the swing arm structurally sound but then again I didn't pay anything for it and I knew it was cracked when I got it

I've heard of a lot of problems with the aluminum swingarms cracking. Most recommend staying with the stock steel unless you are racing and need to go as light as possible.

This one doesn't have any cracks as far as I can tell. I have heard that you have to look at where the shock bolts to the swingarm. This is where most cracks happen from folks over tightening the bolt.

...and from over tightening the axle.

It is essentially a bolt on. But, remember that there are 2 types of aluminum swingarms that Ducati made for the 92-98 900SS and 900SS/SP bikes. There was an update to the aluminum swingarm circa 94 (in the US) to strengthen the top bracing that runs from the sides of the swingarm up to the shock mounting bolt. I'd stick to the updated ones due to strength.

I dunno how many supposed used 900 SS/SP bikes, which only came out from 94-97, I have seen with the older aluminum swingarm.

You can tell which is which because the updated aluminum swingarms have a thicker cross section on the top bracing. Comparing pics from a known 92-93 to a known 94-97 will make the difference evident.

versus....

There is a third swing-arm available as well. The 1000SS (and 800 I think, but I may be corrected on that one) uses a larger "Delta Box" design that doesn't require any additional bracing. It is available in kit form from Ducati Perf. including beraings, pivot, etc etc. I saw one installed on a 99 900SS and it looks awsome! downside is nobody makes a carbon fender for that swing-arm and the old one doesn't swap over.

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Nice bike! Dang I miss her... she only broke the aluminum swingarm twice while I was in care of her. Then when the swingarm broke BOTH at the axle AND at the pivot, they put on a CR's steel arm...

Anyhoooooooooo

The difference between the top mount and underslung swingarms is what goes into the threaded lug on the inside of the right arm. SS/SPs or bikes with the floating caliper bracket only have a hose clamp bolted to the lug. SSs, SS/CRs, and bikes with FIXED rear calipers (be them top mount or underslung) have a post threaded into that lug to act as a guide or stopper for the caliper bracket. It can be ordered from Ducati or something suitable fabbed by a machinist.

Chris

Plus, Chris, your duc had the spaghettis - nice!

If someone will tell me how to include pictures in my post, I will include some of the aluminum swingarm. Then someone could tell me if it is an old version or the new and improved one.

1. the image has to be hosted somewhere the web (e.g., can't be on your computer hardrive).
2. find the address for the image itself (e.g., it should not be a ".html" webpage address but a ".jpg" or ".gif" address). note, websites with frames will often give you a false address for the fame and not the image. you want just the image (try opening the image in a new window).
3. then create the following post in speedzilla using the image's address (but remove all spaces - spaces were included so the text, and not the image, would appear for you):

[ i m g ] h t t p : / / w w w . g e o c i t i e s . c o m / e d w y u n / g p s 4 . j p g [ / i m g ]

Without the spaces, this will give you the image of the red FE above in the thread.

HTH

[Ruptured Duc]

Hey guys,
I've run into a couple of issues swapping my CR swingarm for the SS swingarm. Apparently there are two types of swingarm pivots. One uses circlips and one doesn't. Funny thing is neither one is long enough to stay flush with the outer edge of the swingarm.

I'm thinking of using the non circlip pivot and just center it. The other thing I came across is the shock mount bolt is different between the CR and the SS. I bought a new one, and I'm good to go, but I really am just guessing that the pivot is going to work.

I do have one of the 'newer' swingarms with the caliper bracket pin mounted. I do like the looks of the underhung rotor and bracket though.

Anyway, any ideas or suggestions are appreciated.

[Ruptured Duc]

OK, got the swingarm pivot sorted. I used the shorter pivot, centering it in the bearings. Everything is now done, just as the weather is coming around!

[fraz]

Originally Posted by Ruptured Duc

OK, got the swingarm pivot sorted. I used the shorter pivot, centering it in the bearings. Everything is now done, just as the weather is coming around!

Yeah, I have yet to see the circlip version. I have two distinct aluminum swingarms. The one currently on my bike is from a '98 FE and they are better IMO if you can find them. The top horseshoe part is made of a 5-sided aluminum tubing instead of the standard rectangle. The pivot pin is also a little longer but so is the swingarm pivots on each side. I ended up using my older narrow pivot because it is in great shape and the one I got with the FE was chowdered and very scored for some reason. There were some other things I noticed that were distinctly different but cannot recall now off the top of my head.

As for the brake mount. Yes the SL and FE use the trailing lower caliper mount but since I didn't have all of the hardware, I re-used the mounting lug/stud. My machinist buddy helped me on this one so I didn't scrtew it up but there is a hex for an allen wrench on the inside. That coupled with large vice grips locked tight and some gentle heat, it unscrewed. It wasn't easy, but a solid lock was the key. We cleaned up the tool marks on my bengh grinder and a little wire wheel action and it was purdy again

[ducinthebay]

You probably already figured out that you need a different axle and adjuster plates with the two different swingarms also, or not. Hopefully, you got those parts when you got the swingarm. On alluminum swingarms, you should check your aduster bolts for rust, and add a touch of oil to them to keep them from rusting up too badly. Water can get inside your swingarm, especially if any of the hugger or chainguard bolts is missing. If your adjuster bolts get really rusted, it will strip out the threaded bosses in your swingarm. FYI.

Phil

[rubyvrooom]

Originally Posted by Guest

Plus, Chris, your duc had the spaghettis - nice!

issue with the spaghetti headers is that they prevent a stock under slung floating rear caliper brace from connecting to the rear of the cases. just no clearence for it. it is possiable to get a brace thru there but it has to be fabricated custom.

as for stock swing arms... they are just just look too flimsy. i suggest this baby for ya (see attached).


Metmachex Engineering swingarm from the UK.


Look at how beefed up that thing is... note Delrin plug.


note the rear axle lift spools.


nice rear axle eccentric.

more swingarm images here
http://www.flickr.com/photos/vrooom/...7594552571958/



more 900ss goodness here:
http://www.flickr.com/photos/vrooom/...7594517200754/

[Ruptured Duc]

Originally Posted by ducinthebay

You probably already figured out that you need a different axle and adjuster plates with the two different swingarms also, or not. Hopefully, you got those parts when you got the swingarm....
Phil

Phil:
Good info on the axle adjusters. I had noticed that issue on a couple of other 900SS's and one other swingarm I bought that was buggered up pretty good.

rudy:
That other swingarm looks great, and I thought about going that route, but it's hard to justify when I still have the stock 4.5" rear rim mounted, as well as far to "blingy" for my almost-daily driver.