I have only used the flush mount fillers on several LD bike builds over the past 20 years, with no leaking issues on any of them.
Frankly, I am surprised that some of the side bend extra tall filler necks are even allowed to pass tech inspection.
Depending on the mounting location, some that I have seen have the potential to take an impact in some crash scenarios, which given their leverage, could break them off the tanks creating a serious fuel spill. Don't recall that this has ever happened, but there is a first time for everything.
Thanks for sharing your experience John, that was my worry about dropping the bike and breaking the neck loose.
I am prone to dropping my bikes because of to many knee surgeries, they are a bit loose and don't always hold me up at least I can still pick up both my GT and GS, but it does may my grand kids born naked and bald.
one like the Summit style would probably be easier to move from bike to bike as on has a big top case and the other uses a BMW tail bag.
I would have to take it someplace and get some attachments welded on to it before I ever put fuel in it.
So I designed that tank, and the mount it sits on. Once I had the mount welded up I made a template so I could get the dimensions for the tank that it would clear the grab handles, be set back far enough and leave room for the top case.
I emailed a drawing (revised a couple of times) to Boyd Welding for a quote.
They quoted about $290, incl. shipping and delivered in about three weeks.
When things that act as levers are attached to aluminum, even small forces can crack, break, or tear the aluminum rather easily. Besides broken aluminum levers, I have seen minor parking lot tip overs result in cracked or broken thick aluminum footpeg mounts, snapped aluminum rear subframes, broken aluminum mounting tabs from main frame spars, snapped off shock mounts, etc.
While not a common occurrence, there have been cases of bikes tipping over on an off camber surface and rolling past the point of just resting on the pegs, tip over bars, or side cases. Depending on the mounting position of the tank and the filler location, such a situation could result in the filler neck hitting something solid with the momentum of the bike behind it. That could be enough leverage to tear the filler tube out of the side of the tank (the welds might hold, but they are stronger than the thin sheet the tube is welded to), resulting in a spill. A similar situation could occur during a crash, with similar results...unless the bike is sliding and creating sparks, which might be a bit more serious.
The ease of bending or breaking aluminum is one of the reasons I like to use it for aux light mounts instead of steel. It is light and strong enough to hold the lights securely, but in case of impact the aluminum is likely to fail before transferring a lot of force into the more expensive and harder to repair subframe of the bike.
When you look at some of the things that have happened to rally riders over the years to put a damper on the rather extreme amount of time and hard earned money that riders put into getting themselves to the starting line of the IBR, it seems reasonable to me to do as much as possible to set up a rally bike to survive a parking lot tipover or gravel road bonus crash or even a lowside in the rain. Picking the bike up, finding only minor damage, and continuing the rally sure beats seeing a couple of years of prep going down the drain....or up in smoke.