Removing Nero Corsa "pork chops"

[gstallons]

Fastenal (or anyone else)does not make tools for these threads ! Anti-sieze and bad words helped too .

[Keith Foster]

I knocked out this job over the last week or so. I understand now what you guys were saying about the threaded pin and the pork chop hole and the tricky reassembly.  When reinstalling the RH side 'chop I lifted and tugged on the swing arm to align the bearing ID up with the pin hole as best I could. I enlisted the help of the wife to turn in the pin with the 8mm hex key while I tried my best to maintain position. The problem comes in that (I think) the slightest misalignment causes binding and the pin gets really hard to turn, much harder than what it should. I tried a couple of times with better alignment, lifting, etc, but not wanting to mess things up I took a break and re evaluated. Things just weren't going together right with what I was doing, then I hit upon something.

 

I thought, what if I threaded the pin in like 90% of where it needed to be before I bring the 'chop to the frame? This way I can slide the pin into the bearing freely, then pull/tug/lift on the 'chop instead to line stuff up. Well, I recommend this technique - it worked on both sides for me like a charm. Like I said, thread in the pin most of the way it needs to be, slide the low boss of the 'chop on the end of the long thru bolt (this helps locate one end) then slide the 'chop toward the bike until it contacts the frame flange area.

 

Next, pull and lift on either the rear wheel or the swing arm enough to get one of the 4 bolts started thru a flange hole, finger tighten a nut on the back side to keep it in place. Now, again lifting or tugging, and using a dead blow hammer or mallet, start to work the 'chop in place. Insert another bolt or two. The big tube sticking out of the flange area has a bevel that helps get the 'chop started on it, once you are up on that bevel snug down on two opposite bolts, all the while giving the 'chop a rap - and shazam - the 'chop will be mated up flush in no time.

 

Once you have the 4 flange bolts snugged down or tightened, you can set the pin back to exactly its original position, (providing you measured), and made a 12 O'clock mark (thanks again Andy). The rest of reassembly is straightforward from here.

 

The left hand side is a little easier to me as the nuts behind the flange are a little bit easier to get a wrench on.

 

Anyway, here is a couple of pics with a pork chop after glass beading and after painting with Dupli-Color Metalcast MC-200 red paint. I've got a couple more things to I wrap up and I'll post a pic or two showing them mounted.

 

 

 

[sp838]

Hey, I was wondering if you could describe how snugly the tube part on the flanged end of the spine fits into the back side of the "pork chop." Is it a very tight fit? You mention whacking the plates with a mallet to get them back on... Does this fit seem to add anything structural to the assembly, or is it really being held together mainly by the flange to plate bolt assembly? 

[gstallons]

Use sandpaper or ScotchBrite to clean everything up and then remove all trash w/BrakeKleen . If it then fits o.k. use anti-seize on the mating surfaces so nothing will rust .

[sp838]

That wasn't why I was asking. My question is about how much structural importance the round tube fitting into the pork chops has. If the inside diameter of the pork chop was opened up so that they barely, or didn't even touch, and only the flat mating surfaces on the plates and the flange on the frame touched, would it matter? Does that put too much stress on the bolts, or are they already doing most of the work? The diameter of the tube extending out of the flanged part is 62.5mm, what if the ID of the recess on the back of the pork chop was opened up a hair, to 63.5mm, for example?

[docc]

My unqualified opinion would be that the bolt-up to the flanges is the structural support. Otherwise, I would expect the plate to be press fit onto the cross tube.

[sp838]

The pork chops are made of such soft Al, that's what I was sort of thing too, but ya never know...