I purchased a used 2017(?) Dahon Mariner 7

It's the one with the ill conceived NEOS 7 rear derailleur which are not very reliable and are very difficult to come by.

I was trying some spare parts to see if I could future proof this Mariner with a better derailleur.

By a colossal stroke of luck, a derailleur hanger from an old Schwinn Mesa fit perfectly and is now sporting a SRAM X4 (also lying around)

Looking matching parts, apparently it's a Derailleur Hanger 27 which is fairly common and inexpensive.

Just thought this might be useful for anyone in the same situation.

Pictures man,...PICTURES!

Here ya go!



The last cable support loop (right side of pic) wasn't used for the Neos 7 but it's now utilized for the conventional derailleur.

I'm not fully done with the repair because I tried to dremel the freewheel to allow an 8 speed cassette to be installed. Still wasn't enough room so I have to get a spacer to correct my 'modification'

So, second lesson learned, if you want an extra speed or 3, you'll need a new hub.

Actually you can squeeze on 8 or 9 cogs on a 7-speed hub without metalwork, by using 9- or 10-speed parts (spacers, shifter & chain) with 1 less cog than intended:
Sheldon's 8-of-9-on-7 trick: new life for 7-speed folders?

The funny thing is that I was coming from the other direction and trying to see whether I could fit the Dahon Neos derailleur onto Brompton. In the meantime, I got the Brompton pusher to work well with an extra cog, so the issue sort of went off the table, and now even Brompton came out with their own derailleur hanging from the front of the axle on their new Ti rear triangle.