I'm curious as to when copyright issues might arise in manufacturing components that are compatible with major brands. For instance, would making a stem that's designed to fit Dahon's integrated headset design breach copyright, or would that only apply to a complete bicycle design that clearly appropriates those specific design attributes?

Similarly, despite Brompton patents having expired it appears there's still some claim there to intellectual property rights with regards to the overall design. Would e.g. a third party fork designed specifically to fit the brompton breach any copyright? Or a rear frame?

Copyright applies only to written stuff. You might be in violation of patent laws, but that's a whole other ballgame...

I guess I'm conflating the two, not understanding either particularly well.

It says on wikipedia "Brompton Bicycle's legal actions against Neobike/Grace Gallant have all been brought on the basis of copyright- and industrial design-law". Perhaps in that instance copyright referred only to the reproduction of Brompton's illustrations in the manual?

I am not at all familiar with the case you're talking about. My guess would be either that non-Brompton parties used Brompton marketing word for word or at least similar enough to scuttle the deal, or that Brompton 1. had described their fold very succinctly somewhere and 2. had a very shrewd barrister...

Also not familiar with Dahon's integrated headset design, but... if whatever you design is designed to work with stuff other than specifically the dahon design, I'd think you would not get into trouble. If there's some proprietary interface or measurement involved, it could get tricky.

You could certainly do a one-off for yourself and stay out of trouble, but if you start offering it commercially, that's where the trouble could arise.

Another course might be to get a prototype out there and then see if Dahon is willing to buy the design from you. If only there were someone on this forum who had some kind of in with Dahon so you could get it seen by the right people... *cough* Thor *cough*

Check section 1.9 here https://www.twobirds.com/English/News...Copyright.aspx

Some aspects of the Brompton design such as the curved tube are industrial design choices and there are alternative industrial designs that can achieve the same functionality. The court determined that the clones thus infringe on Brompton public drawings of the bike.

as far as the fork goes , its a 9/8" threaded fork with a 74mm dropout spacing , .
If you wish to hire a custom builder to create an alternative front fork, a single one,
I doubt they will have issues with that,
a single one is not a market threat to their reputation ..
like bad copies of the whole bike.

seeing the way the Titanium fork is made reminds me
of Raleigh's thimble crown 3 speed forks,
with the integrated steering lock .
can't ride off on those, because the locked position is turned to the left.

Interesting, so the folding design itself wasn't the issue since that would have to be protected via patents which had already expired. Rather it was the elements considered stylistic choices, extrinsic to the folding design.

As far as I am concerned, there is really no protection for the truly unique ideas and/or the physical product (bike parts come to mind) once they leave the head, and/or the drawing board of it's creator. This is true for most creative endeavors of the human race. For both the artistic endeavors as well as technical ones:

From an fashion article on graphic all out stealing:
"....Embellishments" = the whole thing
"inspired by" = stolen from
"styles of eras past" = a dress currently available..."
-https://shine.yahoo.com/channel/beauty/guess-knocks-off-target-dress-while-justin-bieber-copies-marc-jacobs-perfume-bottle-2487614/;_ylt=AsX10m4i64IJTjdJcZ3N4lhpbqU5

.

I'd like to look over the Dahon Fusion integrated headset patent. Is there an easy way to find these things online, my searches are ending in the wrong place?