I've been putting this off for a long time now, but I'm planning another trip next holiday and I have to sort this before then. Bike vibrates a lot, and according to GPS, it reaches 60km/h when rpm is ~6k.
Basically the bike is geared too low. Already have 9000km on the bike so far, so changing the stock chain may not be such a bad idea.
Is this some kind of an O-ring chain? All I can see written on the chain is IE, KMC, 428U0


Another view of the chain. From the open side, looks like there is lateral space between one side plate and the other.

Front sprocket is a 14 tooth. Not much space left for a bigger front, can I do anything about it? Not much metal to grind also.

Rear sprocket is a 56 tooth, mounted by 4 bolts.

Another view of the rear.


Any suggestions? I'd like the bike to cruise at 100km/h on smooth asphalt, but i'd be happy with 80. Also important is I can still get out of hairy situations off-road.

Any advice appreciated,thanks