Spent too long in Mil -aerospace wiring, early in my career, for power and signal as an engineer/production supervisor/quality trainer. (F-16 programs, etc.)
For vibration environment, a crimp connection with die sized to the gauge of the connector/wire was considered ideal, with shrink sleaving supporting, over the crimped connection. Finer wires had contacts that had a support built in to the contact that went over the insulation to support the crimped area.
Soldered connections were fine, but not considered as vibration resistant as crimp. Both needed support for maximum vibration life.
Knowing that, I still solder tin stranded wire before putting it under the screw connections on my PC8. My rationale: I think having the solder wick up the wire a bit farther than where the screw hits the tinned area gives the wire the ability to flex over a larger area than just the point of contact with the screw, so maybe more vibration resistant than that particular type of screw connection.
If it gets hot enough to melt the solder, then yeah, there is a whole nother set of problems to worry about.
But really, though, it is a freaking motorcycle, and about anything is better than vampire clamps, that many people think are acceptable...
Courtesy of the moron that wired my sidecar rig, the first time:
No no no!!!!
Broken wire from vibration sawing it through:
Ended up buying the pig tails from Eastern Beaver guy, and fixing the broken wires with crimp connections that have the shrink sleave as part of the connector, then put another, longer layer of shrink tube over that and shrunk it down tight. OCD any one?