Schaller S-Lock compatibility issue

[tauzero]

I encountered a rather puzzling issue on Monday at rehearsal - the strap I'd taken, equipped with Schaller-compatible straplocks by Boston, wouldn't fit onto the Schaller-equipped Ibanez EHB I'd taken. Once home, I checked, and the Boston straplocks fitted happily onto my Warwicks which were equipped with Schallers. The difference is that the Warwicks have original Schallers on, the Ibanez has Schaller S-locks on. I got the trusty digital calipers out and checked the diameters. The original Schallers are 11.95-12mm, the new ones are 12.1-12.15mm. I have several basses fitted with original Schallers or Bostons, and two or three with S-locks, so I have taken a sample. I feel an email to Schaller coming on.

[tauzero]

I had a dig around and found a strap with original Schallers on it (I'm sure there is some mysterious being that hides my straps, I should have about 20 knocking around). That fits the S-locks OK.

 

I have arrived at a tentative theory, that one of the improvements made to the originals was to reduce their rattling, and this was done by making the strap buttons very slightly bigger - .1mm wider and .1mm more from the top of the button to the channel that the lock goes into. If the Bostons were made with the original strap button dimensions and the strap locks a tiny bit smaller than original Schallers, that would have reduced the rattle but meant that the tighter tolerance locks wouldn't fit the larger S-lock buttons.

[LeftyJ]

There was a thread about straplocks recently and I looked this up, because I was wondering about compatibility. Schaller says this on their website:

 

[Norris]

I found the same. Older strap locks fit both old and new buttons. Newer strap locks only fit the new buttons. The newer lock pin doesn't engage properly on older buttons

 

That's not so much of a problem if you use the same strap fitted with older strap locks for all your basses. It's a right pain though if you want to use the newer locks as you'll have to change all the buttons.

 

The newer locks do seem to fit more snuggly, but I never had a problem with the old ones