Originally Posted by
slickginger
Update!
So this is why testing is important. I underestimated the counter-torque requirements of the captive nut pockets, and as I was trying to take pictures Monday night I realized I couldn't get my Brompton bolts out... they just spun because the flats that the nuts rely on for counter-torque had just sheared away in the adapter. I tried like hell to break off the mount... literally jumping on it sideways with the bike on the ground. The good thing is that WOW this thing is strong! The bad part is that I need to dremel my adapter prototype apart to get it off
So I've got a couple plans for how to fix this, but either way it looks like I'm going to be delayed by at least a week. I've verified this thing's strength I think, but now I just need to sort this counter-torque problem so that you can actually take the thing off!
I bet it is not easy to make one or it would be all over e-bay by now
If you are making only one you could try aluminium..
I just drilled a new hole lower down on the B block and used the holes of the Dahon and the Dahon screws.. after digging out plenty stuff to make space for the bigger Dahon mount.
The Brompton luggageblock when mounted on a Brompton the sides of it encloses the the mount on the frame. I bet this makes it stronger and helps stabilizing the whole thing (block with bag). Same with the older clickfix bag holders. I have not seen the new alu ones close up (are they Dahon or Tern) but my impression is there is nothing on the sides, just strapped to the front but then again it is aluminium.. Your adapter is just holding the parts against the front of the mount with with the bolts and nothing on the sides and top to stabilize the whole thing. Did you give this some thought?