IMHO..... What "is" or "is not" common sense is often opinion based. Disconnecting electrics is more of a fail safe procedure....

That's why HD recommends pulling the fuse or disconnecting the battery for just about any repair..

Properly disconnecting the battery will ensure that anything electronic that is near, or connected, to anything you are "fixing" can't have power to it, and is the ultimate protection for the ECM against shorts or 12v feedback (note: welding on the frame requires extra precautions) ... Pulling the fuse will remove power from accessories and everything but the starter (that has a direct, live power cable from the battery).

There are times when it's absolutely necessary to disconnect the battery and/or fuse ...

There are times when it's prudent, but not necessary, especially if you are careful (or lucky) ....

There are times when it's not really necessary, but can't hurt....

Let your knowledge and experience be your guide. When in doubt, it can't hurt....

 

'good sense and sound judgement in practical matters". Or as it is better known common sense. Opinions do not necessarily require any of these. 40 years as a heavy vehicle mechanic have turned common sense and education into many of my habits.

In my opinion internet forums and its members have an obligation to give safe well researched information. There are questions posed for reasons. Some people have limited experience or knowledge so to omit basic mechanical and engineering practices is irresponsible.

I would argue that not only harley but just about every manual suggests you disconnect the battery pre any work being undertaken.

 

I recommend you add a lock washer to the cables. I have found that these bolts can loosen up overtime...lead posts, soft metal, can't really "torque" them down tight. I call these star washers. They are both internal and external teeth. I have McMaster-Carr listing below, but you can get at any fastener store.

https://www.mcmaster.com/standard-washers/lock-washers/

 

Yes disconnect