$45 seems like a lot for such a small fitting.
As an aside, thanks for posting that. A few months ago I was going through the workshop of a friend of mines father-in-law who passed away and found a grease gun with a similar fitting.
I wasn't sure exactly what it was for but looking at that photo it looks the same. I think it might be missing the rubber seal.
Now I suspect he probably used in on his ancient Kubota tractor.
I haven't tried it yet on any of my bikes. I only have couple that I haven't replaced the zerks already.
I agree, $45 is outrageous.
If you do end up trying that coupler on the older fittings I'd love to know the results, preferably with pictures of course!
if youve got an old barn find or weathered bike the grease WILL be rock hard set and wont budge full stop no matter how hard you hold the wrong fitting against that pressure,no one greased em much in the day anyway?once restored cleaned up with proper zerks a pump of grease once a year will do.
This is important information for sure, I always disassemble and re-grease when I don't know the history of the bike.
I use the second method - only difference from using standard grease nipples is that you have to hold the grease gun fitting all the way on while you pump the grease in - the faster you try to pump the grease in the more force it will take to hold the fitting on - I pump the grease in very slowly while pressing the fitting on very hard - if the fitting pushes away from the nipple either I wasn't holding it on hard enough or there is a blockage somewhere inside.
If grease always goes everywhere but into the nipple you need a new fitting on the end (or a new grease gun).
John
This is also my current method. I have a few too many bikes to want to replace the fittings on all of them.
My biggest curiosity is if this fitting I found will reduce the mess of using the old fittings.