Its not a matter of wishing...I am looking at the part on the HD website. Fitment says 2016 FLHXS compatible. I guess it wouldn't be the first time they were wrong.

 

Might be I do know the standard cover will not fit a narrow . That is why I just gave my nice one away it would not fit the 2016.
When you first look at it they look the same but the narrow cover is larger.

 

After closer inspection (holding new cover over old one) I can confirm that this is true - narrow derby cover is around 1/8" larger diameter.

 

I have that same Derby cover on my '15 Limited.
Yes, you need that gasket (or another brand of similar design).

The gasket on the factory Derby covers are meant to be used on the factory cover only, as those covers have a groove to accept the gasket.

That gasket is for the stock factory derby cover only.
There is no groove machined into any of the other derby covers that will accept that type of gasket.

 

I had the narrow derby cover in my hand this afternoon - there IS a groove. I'll post a photo tomorrow but in the meantime - here's the 2016 fiche.

 

Yes, the "Factory" stock derby covers have the groove.

For the old style wide primary cover:
None of the custom derby covers in the parts and accessories catalog have that groove.
They are completely flat on the back (sealing side) of the cover, and take the gasket type that is listed for that part number.
The Derby Cover that milleda31 posted a link too take the flat gasket, as I have that same exact cover on my bike.
It is NOT the low version.

 

Sorry, nope. This is a "factory stock" cover as you put it - the narrow version used on all 2016 touring models and 2015 low models, I'll post the photo tomorrow...........left the cover at the shop.

 

All I am saying is the Derby Cover link that milleda31 put up in post#14 will not use that o-ring type gasket. It takes the flat one.
This Derby Cover takes the flat gasket: http://www.harley-davidson.com/store...by-cover---103

I haven't seen any of the narrow primary derby covers, so I wasn't speaking for them.
Only for the old style primary derby covers.

 

What Rollamo says is correct. Stock covers (what came ON the bike) use the orange rubber oring style. Anything else uses pancake style on the "normal" primary case and derby.

Not sure about the "narrow". Also, no idea why it would need to be larger? Other than to make you spend more money.

 

Personally, I like the looks of the big, bulky one on my "15 Limited.

The only problem I've ever had was when I moving the bike around in the shop after riding it home the day I bought it on a 95+ degree day and after changing into shorts.

DO NOT touch the primary with bare skin under those circumstances. Also, don't ask me how I came to that conclusion!