Top speed issue?

I have a 2012 Silverwing with 15,000 miles on the clock.
About 8mths ago, I did a couple of long motorway journeys and during these rides, had no issue hitting 100mph.
Ever since however, if I approach 100, my revs are bordering the red.
I cannot figure out what the problem is, certainly nothing obvious although I will admit that I'm far from mechanically minded!

What are your standard top speeds and does anyone have any suggestions?
Cheers

You may want to check simple things like your spark plugs and belt. Also, does it run smoothly? You may have a dirty fuel filter. I would check the simple things first though. If you get the problem solved please get back to us with your answer. Did you put a bigger screen on it since 8 months ago? The stock Givi screen kind of effected my power since it is so tall.

It's getting a service next week, New belt, and Dr Pulley sliders too. Will post an update afterwards.
No new screen or anything although I read someone's post about a binding front wheel and I've had similar issues since an accident so going to get the front wheel thoroughly checked out too.

I got 104mph verified by GPS on my 2002 SW. I don't remember exactly but think a run on my 2004 was a squeak faster with its Givi Adjustable windshield. It was close enough it could have been just a temperature or wind difference so I'd call it the same. Top speed was a lot more comfortable with the Givi. With the original shield I got an odd pull upward on my helmet starting around 80mph and getting pretty firm once near 100. With the Givi there was little buffeting at all untion 85 or so when I got a big of pressure pushing on my back. Not as annoying as the pull on my helmet with the stock screen.