Hiya &

to the HUBB...
In What way do you mean restricted? they arent real powerfull to start with!
if you want a FAST bike, get rid......
If you want a bike that will cruise happily at 65-70mph and will return 60mpg you have it.
If you want a bike that will go just about ANYWHERE,, you got it!
If you want a bike that will give you more smiles per mile and actually handle a damn site better than a traily should... you got it.
I regularly ride mine ( 1989 vintage 2KF XT600) beyond what I think it is capable of! It actually goes round the twisty roads here in Spain at a rate of Knots that has to be seen to be believed! The tyres are Heiddenau catspaw Trail and although iffy in the Wet.... are great in the Dry ( I haven't found the limit yet, although I do try... they have slid a little but never enough to make me scared..

)
What is the top end speed on your Bike? mine tops out at just a shade over 90 ( 150 Kmh) although speed isnt what the XT is about it will outhandle a lot of other bikes on the twisty roads.
Martyn