BMW S1000R change of tyres : Michelin Road 6 rear tyre bulge from new / severe vibration and bobbling above 70mph

Change from Pirelli Rosso IV to Michelin Road 6  (same sizes)

big front end vibration (up and down) not side to side at 80mph +
note this is NOT headshake

Reasons for issue could be

• Out of balance
• Tyre not seated on bead fully
• Wheel out of round
• Tyre out of round 
• Tyre / suspension combo wierd

I did read that issues with the rear tyre and manifest as a front end issue

subsequently found bulge on the rear tyre! (from new)

clearly something amiss in the construction as you can push your finger in to it.
once tyre was removed there was no evidence of a problem from the inside surface

rear replaced at AG expense and form completed for a Michelin claim

front removed, rotated 180 and refitted

static balancing used

Hats off to Adam at https://www.facebook.com/AGMotorcyclesManchester
for coming back to my house, replacing the rear and refitting the front.
Great customer service, even though as a private business he's out of pocket.
Even if Michelin honour the rear tyre defect claim, he's still out of pocket for 2 journeys and another morning fitting.

After several weeks the issue is now resolved 

so the root cause was either  (or a combination of)

• front tyre not seated correctly
• front tyre not balanced correctly
• rear  tyre defect causing overall vibration (appearing as front vibration)

I cant prove it, but Adam is an ex bike racer and knows his stuff, so I find it very unlikely the issue was the front, Im more likely to believe its the last reason that the rear tyre defect was manifesting at higher speeds as an overall vibration.

Its also worth noting the change in tyres has had a noticeable change in feel to the bike.
'vertical bobbling' still occurs (which I really didnt have or notice with the Pirellis)

So the overall construction between these two tyres is clearly very different.

current pressures are the recommended 36f / 42r

Im going to try reducing pressures, removing some preload (im maxed out front and rear) to see if it removes the bobbling

13920 miles front and rear changed to Road 6
14120 miles rear changed due to bulge