Crankshaft/ flywheel query

Hi all - I have been wondering about something since talking with my neighbor about some problems he is having with his 2015 HD Twin Cam motor .
In doing some internet research apparently there is a longevity issue with the cam chains , pinions & tensioners. Some feel that since the crank pin is pressed together it may be prone to the wheels getting out of true and causing the timing side pinion to run erratically.
Perhaps someone can explain how this can happen if the main bearings are sound and concentric. To my mind if the bearings are concentric how can the flywheels become non - concentric ..
I can understand the two wheels becoming untrue out of the crankcase but it seems unlikely to me that it would happen when assembled in the crankcase.
Puzzled …

I believe it’s down to riding style. Lots of chugging about at low rpm / high torque puts great load on the primary output shaft, effectively twisting the crank.
Same when heavy engine braking is used.
Having the crank pinned and welded is the ‘done thing’ with these motors before any serious tuning work, for the same reasons.

Or the Cranks weren't true when assembled which is my suspicion, I vaguely remember being told that HD changed the tolerance for runout at one point to avoid warranty comeback.

Fast Eddie said:

I believe it’s down to riding style. Lots of chugging about at low rpm / high torque puts great load on the primary output shaft, effectively twisting the crank.
Same when heavy engine braking is used.
Having the crank pinned and welded is the ‘done thing’ with these motors before any serious tuning work, for the same reasons.

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I think many people do not know how to use a gearbox. I once rode my mate's Triton, and it went much faster then it ever did when he rode it. I had raced against it for years and I know how fast he was. and is.

2015 crank is pressed and welded together. Many are not "TRUE" from the factory. Good enough for everyday use not abuse. When changing oil pump you must leave bolts loose and turn crank thru so oil pump centers on crank! My 2014 blew-up three times, stage 4 engine, dealer asked if I changed lifters after 8000 miles?!?!? Gave up modifying Harleys for street, they cost a LOT to get them to live! Riding a stock 103 now.