2_i 

This is a follow-up to the 2 Chainring thread. During the work there it became apparent that there was still space left on the drive side and one more ring could be principally added. 2 rings worked very well but last month, in a hilly area, I ran out of gears and had to walk up. Given that the next month I am to spend in an area that is even more hilly, I started looking into the third ring option seriously. For exploration I got an IRD Triplizer 34T 110/74 BCD and a 24T 74BCD ring. It turned out that a 116mm BB, shoved to the right gave enough space for shifting on a 50-34-24 crankset. At this point I am using a double braze-on derailleur which gives an iffy indexed shifting - a triple derailleur should come in next week. I switched from a Sunrace friction shifter to indexed. The friction one worked a tad better in the current configuration, but I hope this will get remedied with the anticipated triple derailleur rather than the adapted double. I added an in-line shift cable adjuster from Jagwire, due to the lack of cable adjustment on Sunrace. It looks most of this is going to stay - my lowest Brompton gear is now nearly as low as the one on my main bike . One of the photos compares folded Bromptons with 1 and 3 front rings.