@ #5:
"What a strange decision, to make a cruiser you cannot use to cruise on highways, which is the definition of cruising."120 KPH = 72 MPH ; The Meteor makes about 20 HP. ; The Meteor gets about 86 MPG (37Km/L). {1Km/L = 2.35 MPG}
As Derottone already pointed out, speed is merely a function of HP & drag. ( 1 PS = 0.98632 HP )
Motorbeam lists top speed as 115 KPH or 69 MPH. That'll be on flat, good pavement, windless conditions.
Unless you are turning max HP RPM (6100) at 115 KPH, you'd actually need to
gear down to increase speed.
Enlarge the final drive sprocket until you find the point where max HP RPM balances drag at top attainable speed.
And THAT will probably be unpleasant & buzzy on a single, so you'll end up putting the stock sprocket back on.
Historic rule-of-thumb says it takes about 30 HP to run 100 MPH (160 KPH) on an unfaired motorcycle.
From real world experience, a 30 HP motorcycle is reasonably comfortable at 70, windless & flat ground, with even some throttle left over.
The vaguely gynecological riding position of a cruiser is less aerodynamic than that of a "standard" motorcycle, so a cruiser takes slightly more power at a given speed compared to a standard.
Again as Derottone says, nothing bad will happen to the motorcycle at 72 MPH, it just runs out of "poop" at about 70.
Speed costs money - how fast can you afford to go? If you actually "need" to run 72/120+ for hours on end and have to have a new bike, save up another $2k USD and get the 650 Interceptor.
Otherwise, either learn to be happy with a 60-65 cruising speed
or acquire a 500cc or larger used twin cylinder machine.
For myself, the wind buffeting at 75 isn't too much fun. Riding's a lot more pleasant at 55. Keep to the secondary roads & enjoy life more. Let that 86 MPG keep your money in your pocket.
https://www.motorbeam.com/2020-royal-enfield-meteor-350-review-test-ride/Royal Enfield Meteor 350 Specifications
* Engine: 349cc, Single-Cylinder, FI
* Power: 20.2 BHP @ 6100 RPM
* Torque: 27 Nm @ 4000 RPM
* Transmission: 5-speed
* Top Speed: 115 km/hr (VBOX)
* Fuel Consumption: 37 km/l
* Fuel Type: Petrol
* Suspension: 41 mm Telescopic forks (Front), 6 Step Adjustable Twin Shock Absorbers (Rear)
* Tyres: 100/90/19 (Front), 140/70/17 (Rear)
* Brakes: 300 mm Disc (Front), 270 mm Disc (Rear)