Saw this on a Facebook Cycling Group Page. A simple, no sophisticated tools required, DIY job for making old frames designed for 27 inch wheels, work with 700c wheeels and short reach brake calipers.
Thought about doing this for my CFX-10 (it was designed for 700c brakes, but of the long/medium reach variety, and I really wanted to use short reach brakes). In the end, I decided to go with medium reach and I was glad I did.
But when I was researching my problem, I couldn't find any help with building my own rear brake dropper and when I saw these photos on FB, I thought it would be a good idea to have them permanently on the internet and searchable, so anybody could find them.
I asked Mal Jones, the original designer (and publisher on FB) if I could reproduce them here and he is happy to share.