Finally came in and was able to get it back together. It's a perfect fit, exactly as calculated. 2 more links to the chain and I get perfect clearance between tire and swingarm.

 

And here's the results...

 

I'm waiting to speak to a couple of people who have done the modification to get their feedback and recommendation, but I think I'll settle around 20mm or 25mm stretch.

In the meantime I've started looking into the gearing. Currently I'm running 15-41 with 100 chainlinks. It's better than stock, but I still at time find it a bit too tall on certain low speed turns so I'll use this as an opportunity to change the gearing, since I need to account for the taller tire anyway (we're looking at a circumference of 2,124mm of the 200/65 Vs 2,061 of the 180/60 so 3% greater distance per revolution)

It appears that a good combination would be a 14-42 with 102 chainlinks. That would move the wheel back 15.5mm (effectively adding 15mm of clearance between tire and front of the swingarm given the tire is currently just rubbing) which assuming a 20mm extension means the eccentric is turned counterclockwise from the 3PM position... So basically from a chain adjustment perspective I'm good. I think I may have to get a shorter height adjustment link, but I'll get there once I get there...

From a geargin perspective it calculates out that in 3rd gear at 60mph I'll move from 5,500RPM to a tad over 5,800RPM which also is good. The only part that I don't especially like is that the combination of front sprocket tooth, rear sprocket tooth, and chain link are more syncrozied than I'd like: it looks like the same link and tooth (both front and rear) will mesh every 7 revolutions... Not optimal, but of all the variable it the one I'm least worried about.

I'd encourage anyone to review the gearing analysis attached and let me know if you have any other observations

 

Kudos to OP for the dedication and positivity. No such thing as a problem when you're focusing on solutions. It does seem strange that the manufacturers would stop production on a tire that would seem to still be a very viable market. 10+ year old motos are pretty common at trackdays, and I would assume club racing.

 

So I did title it "My JOURNEY", didn't I?!?! Not my first time at this kind of rodeos...

I was all happy with my swingarm off the bike ready to send it to Pierobon, but after some additional back and forth with them turns out that a Dunlop 200/65 is too tall for them. And although I didn't get too much into the details is not just the height of it, but also the shape that doesn't work with their modification...

But ehi, it's a journey right...... So ;'m back at square one and through some additional research in this awesome forum of ours turns out that the Streetfighter has a longer swinger -> https://www.ducati.ms/threads/street-fighter-swingarm-on-superbike.115087/... Well, that's promising!!!!
Unfortunately, although you do increase the wheelbase, it's increased in the wrong place: namely the center sheetmetal section is the same and it's the front casting where the swingarm mounts to the frame/engine that is longer... And it has an ugly corner that occupies the same space of the exhaust

But it's a JOURNEY... Next thing I found is a video of a fabricator up in Ontario posting a video, of all things, of how he goes about stretching the 1198 swingarm

So I give him a call, go back and forth on a couple of emails and turns out that he has done 10 to 15 of these swingarm to various people, some drag racers going very long and some other people who have the same issue I have. Now the only thing I need to decide is how much I want to stretch it for...

 

^ sounds like this is your only option if you want to utilize these size tires. I guess I'll stick with riding and racing on Metzler 'track day' slicks for now as they're available in 200/55/17.

Out of curiosity - what's the cost of this modification? I know anything with the 'Pierbon' label isn't cheap. Maybe I could find a used RS swingarm..hmmm.

 

Here's how it currently looks. Although it clearly rubs at the front, the wheel is not forced in, and spins with relative ease

 

The Pierobon solution seems like a good one. They're good to work with - and visit if you're near Bologna

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The Pierobon solution seems like a good one. They're good to work with - and visit if you're near Bologna.

Visiting them is absolutely the case!!! As a matter of fact, the plan is to go pick it up in person when I'm there in July

 

Pirelli isn't an option?

The venue I normally do track days with works with Dunlop. I was checking Pirelli and their Diablo Supercorsa Slicks in 200/65 are advertised at a 672mm diameter so they too wouldn't work. They also have a 200/60 which is 662mm, which may fit, but it would be tight...

676mm?!! Lord, that's huge. And also what she said. Is Pierbon going to cut and add length rear of the shock mount similar to the Corse swingarm?

They actually leave the length intact. What they do is they recess the front part of the swingarm where it comes in contact with the tire. From their website"

"The upgrade allows to mount 200/55 and 200/60 tyres.
It can be applied to 1098, 1198 and 848 swingarms

At first we disanodize the swingarm, than we remove the part where the swingarm comes into contact with the tyre.
The opening is closed with a moulded sheet metal part by welding.
At the end we proceed with dimensional control and painting in black matt."

 

Pirelli isn't an option?

 

676mm?!! Lord, that's huge. And also what she said. Is Pierbon going to cut and add length rear of the shock mount similar to the Corse swingarm?

 

Good point!!! Slicks sizes varies: the Dunlop Sportmax Slick 200/65 is advertised at 676mm in diameter (vs the 656mm of the old KR452)... So yes, awfully close

 

It’s gotta be awfully close. My 1198 had a 200/65 Bridgestone rear with 15/42 100 link setup and it cleared.

I’ve since switched to a Metzler Trackday slick in 200/55 656mm diameter and most recently used 15/40T with no problem.

The 200/65 Bridgestone was advertised as 655mm.