Front tire is also brand new (now about 1k), the reason why I've waited a week for the tire was I wanted to have same model tire front and back

 

Let me clarify again so there won't be misunderstanding - there was no blowout. I've ran over something on the intersection and heard pop in my FF helmet. Pressure was dropping fast, so whatever it was - was big. While waiting for a tow I've rolled it back and forth and couldn't find any foreign objects or tears.
Yeah, learned my lesson about goo lol.
No, before flat tire there was no issue with stability - triple digits on occasion.
Something caused tire to fail, I suspect. The reason for the suspicion is that I was going through intersection with construction on one side.
As for mechanicals - I don't see anything obvious. Tire had been changed by the dealership where bike was towed.
Tire is brand new matching my front (Cruisetec both). Front now has about 1k miles. Both tires were replaced at the same time then in about 500 miles I've had a flat.
More update - on my lunch break pulled the wheel off again and check for true - seems to be fine on both sides of the rim.

 

The rim is probably fine.
I am questioning the new tire.
Check the runout on the tire sidewall, and on the centre of the tread for axial runout.

Please report back.

 

Could, and this is just a WAG, could the big hunk of your TPMS come loose from the valve stem and is now throwing your wheel out of balance when at that magic speed?

 

That makes sense, thanks for the idea.

 

I took the tire off when I was cleaning valve stem and insides from the balancing goo, TPMS was tight.

 

You said it was towed. Did someone ratchet strap it in the wrong place/area maybe and crunched the rim somehow?

 

It was ratcheted by the saddle bag guards, was the rim crunched, I don’t know. At this point I’m grabbing at any straw lol. I did check the rim for true, both sides look good, will do tire check for true tomorrow, as Highway Handler suggested.

 

Does the RG have rubber engine mounts?
I ask because my son brought a friends RK to my shop and we checked alignment, neck bearings, fall away, tires, etc. - only to find he had a worn engine mount causing wobble at higher speeds.

 

Jack the back end up, place a Coke bottle (or anything tall enough) beside the tire, spin the wheel.................what is wobbling the tire or the rim or nothing? If everything is coposetic your wasting your time chasing a tire issue.