Here's a photo of the device I'm referring to, it's called a Safety Braker. I've read differing opinions on their effectiveness, from a 'must have' to 'junk'. They are supposed to stop brake lock up and are claimed to reduce stopping distance.
Does anybody out there have first-hand (or reliable second hand) experience with this unit?
Wow! That's an antique. I've got one too, new in the bubble wrap.
I ran one back when they were current items, on my roadracer and then on the street. It gave a slightly more appealing feel to the braking, which may have been psychological. I'd say it made them more progressive, as i had a hair trigger set up prior to installing it. I never locked a wheel before during or after, so i can't say.
Hard to say if it decreased stopping distances. Like so many such parts, there were no objective test results. But it didn't increase them I'm pretty sure. I had twin discs on with it. My biggest problem with it was that I tended to fall a lot back then. It stuck out so far from wherever you mounted it (mine was off the master cylinder), I was always afraid I would break it off.
I say run it as a period part and see what people say about it. Now that you've brought it up, I think I'll run mine for a while at least, for the "parking lot" value. It did not survive commercially so I guess it didn't interest enough people.