Swingarm refinishing

got2dv8

I started pulling my chassis parts out to clean them up. The swingarm was really mucked up with dirt and grime. I cleaned it up best I could and then noticed the thing is painted. I noticed because there were many places where the paint had rubbed off. I am now in the process of stripping the remaining paint with acetone. Were all 851/888 swingarms painted or were some bare? Curious because I was wondering if I should leave it bare or repaint it... I'll definitely hit it with some metal polish after it's completely stripped to see how it comes out. But, I am not sure if it's a good idea to leave the aluminum bare and unprotected.

Thoughts?

Robert

jr60

Hi Robert

You sure that the swingarm is anodised not painted, I know mine was. Become bit of an old hand at this having polished up 4 Ducati swingarms - all of which where anodised including the 888 one.

To remove the anodisation you need to dip it in some caustic soda solution (NaOH), but be very careful, if left in to long it will start to dissolve the Al too!

I then rub it down with 400 then 600 wet & dry and then on to the polishing wheels.

As far as if to leave bare or to lacquer, if the bike is not used everyday and nicely polished it will only needs the odd polish up with some metal polish to keep it looking good. I lacquered my st3 swingarm and wished I hadn't very hard to get a coat that bonds to the polished metal with out chipping off very easily.

Johnny

wgsvintage

Hi Robert,
The only problem I've ever had with bare aluminum (polished or not) has been exposure to salt. Had to tow a race bike on an open trailer in early winter. Roads were clear and dry, but hadn't been washed by rain, so there was a little salty dust still there. Sprayed it down right away, but there were some ghostly looking marks on the aluminum. I'm old enough to remember the Japanese bikes from the '60's & '70's that had a clear coat of some kind on the aluminum. It looked great for a few years, then not so good. I wouldn't put anything on bare aluminum, but try like hell to avoid salt.
Bill

marvin

Robert,

If the "paint" is coming off with acetone it is indeed paint. Anodizing won't come off with acetone. If it doesn't look too bad when you get the paint off I would leave it alone. Upkeep on a polished (un -anodized) SA is more than I care to do. Re-anodizing it would be a PITA as you would have to remove all of the steel threaded inserts, strip it, polish it, then anodize, install new riv-nuts. MarkT has been going through the same thing with his Polen swingarm. Normally I would just anodize it for him but I have down sized my outfit and my sealing tank is no longer large enough.

dhumphrys

Is it definately alloy? Could have been replaced with a steel one off a Monster. Some M900s has steel swingarms.

marvin

dhumphrys wroteIs it definately alloy? Could have been replaced with a steel one off a Monster. Some M900s has steel swingarms.

When did Monsters have steel swingarms?

Mr.R

marvin wroteWhen did Monsters have steel swingarms?

The later 900 Monsters came with a steel swingingarm.

Steve R

dhumphrys

Mr.R wroteThe later 900 Monsters came with a steel swingingarm. Steve R

...and all M600s and M750s had steel arms too. I'm not sure if the M900 arm was wider to take the 5.5" wheel (600s and 750s had a 4.5" wheel) but I think that's unlikely.

My assumption is that Ducati had a stock of steel arms and didn't want to get more alloy ones manufactured ahead of the new injected Monster and ST range, so they bunged a steel arm on all carby Monsters at the end of its production life.

jr60

While on the topic of swingarms - ever where all the 851/888 swingarms have gone.....

Somebody (Roy Thersby) is moding them to build (beautiful) TT1 reps, see this link for a write-up of a build of one (from which the pics were taken);

http://www.ducatisti.co.uk/forum/ducati-pantah-tt/27020-tt1-f1-endurance-replica-6.html

Johnny

got2dv8

Got her all stripped of the paint. Now I know why it was painted. There are some portions where the anodizing is cloudy/discolored and there are some spots where the surface finish is actually worn away. Luckily those places are in areas which should be mostly unseen when installed as I don't want to paint or re-anodize it. The first four pics are before and the last four are after. It looks pretty good... better than it did.

Robert

sp2 boy

jr60 wrote

Johnny,

my understandong is that the swingarms are modified standard Ducati units. So rather than actually being a source of supply for them, Roy is actually using up available stock!

PS Just re-read your post and I have repeated what you have said. I should remind myself not to answer posts as soon as I have woken up...I am still sleepy and real dopey at 6.30am!

hauge

Mine looks like this after some work.

sp2 boy

hauge wroteMine looks like this after some work.

What about the inner part, have you done the underside? 😝

hauge

sp2 boy wroteWhat about the inner part, have you done the underside? 😝

Haha!
Yepp, underside is done. Didnt bother to do the innerside. It did take some time anyway...

brad black

the steel swingarms have the later 3 screw hugger, where the screws go down into the top of the arm, same as the 95 or so onward 900m alloy arm. the 900m got the steel arm on the dark version and maybe also the later base versions, i forget now. from 2002 onward with the st frame the steel arm is the same as that fitted to the st2/st3/st4 and the alloy one same as s4/st4s. from memory there's actually very little weight difference - who has the numbers?