There are numerous resources in the internet on how to break in your motorcycle but very few of them would clearly explain its purpose and merits. While newer engines - in general - have been broken in at the factory during its vehicular production, the process of engine break-in for the ending consumer has become customary, with motorcycle manufacturers releasing very little bits of information about the process in the owner's manual.
Anyway, I did my own softly extensive research on how to properly break-in a motorcycle and why we should be doing it. The most important thing to break-in there is actually your engine, even though some pundits may technically point to breaking-in every critical part of your motorcycle, which includes the transmission system, the suspension, the wheels and tires. The process of breaking-in the engine is actually not about speed, but about the capacity of the engine in withstanding varying degrees of compression. This means that you should play out your RPMs (revolutions per minute) in the widest range possible throughout your break-in period, keeping in mind of not maintaining a single RPM speed for extended periods at any given time. This also means that maintaining a 60, 80 or 100 kph speed and keeping it constantly in that manner for possibly 2 or 3 minutes - or more - is the wrong way of breaking-in your engine.
For practical purposes, you should play your speed from 25 or 30 kph to 100 kph repeatedly and cyclically during your break-in trip/s. In the most ideal sense, the best break-in for your motorcycle would be to ride it while gently increasing your speed to the maximum that it can do, or up to the maximum RPMs that the engine has been designed for, and then gradually decreasing your speed to the minimum that you can sustain, and then repeating this process cyclically, during your first 1,000 kilometer odometer reading, or with what ever is specified in your motorcycle's owner's manual.
In this light, it is theoretically possible to do a simulated engine break-in while having your motorcycle mounted on its center stand or a paddock stand or while having it geared in neutral, wherein you will cyclically, but gradually, throttle your engine to cover its widest RPM range possible. Do this in a time frame that you can imagine where you would have simulated to cover a thousand kilometers while doing so.
Contextually speaking, breaking-in your engine actually addresses its durability (number 1), reliability (number 2) and performance (number 3) in that sequence of purpose priority. The other metrics, such as rate of efficiency are only consequential to performance, meaning if the engine performs optimally well, then it tends to become more efficient at delivering power (technically horsepower, or more loosely, speed) while consuming the least amount of resources (fuel).
Further reading:
Wikipedia article on Break-in (mechanical run-in)
http://www.motorcycleextremist.com/Motorcycle-Engine-Break-in-the-Right-...
https://rideapart.com/articles/how-to-break-in-a-new-motorcycle-engine
http://www.mototuneusa.com/break_in_secrets.htm
http://www.lazymotorbike.eu/technical/breakin/
http://www.superstreetbike.com/scenes/best-way-break-bike
https://www.bellperformance.com/blog/the-proper-procedure-for-breaking-i...
http://www.dansmc.com/engine_breakin.htm