Question about Speed

Hello,
My T80 is now 'restored' with a 'new' Frame from Greece.
Now I have a Question:
My T80 has appr. 24000mls on it and Does about 45mph on the flat, the most time it runs about 35-40 mph.
Idle and starting ist very nice. No Oil consumtion etc.
But it will never get to 55mph as in the Registration Papers also not downhill...
Is there anything to worry about or is the speed normal?
I also have about 120kg myself.
I don't want to pull the Head and Cylinder, as it is not very easy to get the gaskets in Germany.....
greetings and merry christmas
Tom

45 mph is about the top speed on the level, you may get 50 mph on a down hill but thats the real max. 35 to 40 mph is a good cruising speed. I am intrigued by you saying it should do 55 mph on 'registration papers' the V5c document does not give performance figures. Your bike seems to be performing on par.
You say you got a new frame from Greece, was this a genuine new Yamaha one or a pattern one? Genuine new Yamaha ones have not been available in UK for some years.
Just one other thought, do you have the correct T80 rear bevel drive, the T50 one looks identical but has a lower ratio. T50 is 3.589 : 1 T80 is 3.166 : 1

Ok then it is fully ok.
No, i didn't use a really new Frame, i bought a used T50 Frame in greece and restored it.
Although everybody says, that greek frames are not rusty, this is not true;)
On the greek frame i had to fix two little holes on the rear fender, but not worth talking about!
Ratio is original, the bike drives at very low rpm.
Much nicer to drive than a C90!
The C90 drives much more nervous than the T80!
greetings

Are you in UK? must have cost a fortune to import a frame from Greece

No, I am from Germany, and i am the only one in Germany now, who has a fully registered T80 Townmate;)
I bought the frame on my anual trip to greece this Year, but i couldn't take it home with me on my Africa Twin;)
So my father brought it 4 weeks later in his mobile home to germany;)
Greetings