I have had Nortons for over 50 years but never managed to find a grease gun that fits the nipples on a Dommy. Its time I solved that issue. What am I missing?.
Which, in my experience, never fit properly and you end up with grease everywhere. Old timers suggested that a bit of cotton rag between the nipple and the nozzle worked but never for me.
I replace them with modern type nipples that current grease guns will lock ("hook") onto. Not original but I suppose if you really wanted to you could fit the new type to grease then refit the old ones for "originality".
1/4" BSF thread if I remember correctly.
The one I would like to service is on the brake lever ,and that is extended to retain the lever,so no modern fitting . Ah well.
The original prewar type without the locking ball seem to be unavailable anywhere. I'm keeping mine on the old 16H for appearance sake. When I put the bike back on the road a couple of years ago I took each one out in turn and put a modern one in so I could pump the dried out greaseways clear (girder forks). Then put the old ones back. A scrap of cotton cloth (old shirt) then seals the connection and allows the originals to work fine.
Ian Soady said he hasn't managed to make the cloth trick work (nor me, in the days when I worried about such things).
Is there some special knack, beyond simply interposing a layer of material between nipple and gun? Does state of the material matter (e.g. new vs. threadbare, thread count, etc.)?
Not really a special knack I know of. I usually use a small square piece of old poly cotton shirt material! It does need the greaseway not to be dried up - hence the use of a new type nipple with hand lever type pump action to get the old ones free on a bike not used for over 25 years - (but kept inside a house for much of that time...).
To be fair - a fair bit of grease tends to escape when I grease the 16H forks. But most gets in where it should go. Without it the grease goes more or less anywhere.
Whichever type of nipple, the old push-piston gun will work. They do have the advantage of coming in lots of sizes. You can get miniature ones small enough to fit in a tool box for next to nothing at Kempton or similar.
Biggest problem I have is re-filling the things. Sometimes it's no problem (just a bit messy), but sometimes they seem to get an airlock and won't work at all. I'd like to know how to solve that problem.