Will 140 mm. do?

Here's a M3L with 140's I fitted recently.

I rode a similar Brompton earlier in the morning with the standard 170's, then this one later, & I felt a considerable difference.

It seems there's a "changeover point" for me at 140, as my 150, & 155's don't feel as different when going from 170.

My shortish test ride was about 2 mph faster than the bike with 170's, & my cadence was much higher.

I imagine, but don't know, that my power output was also better, & the area above my knees (don't know the anatomical details) felt like it was working harder.

I'm keen to see what happens after I've ridden for say 50 miles, & the longer term effects.

I don't think I'll experiment with smaller sizes (eg. 127 mm. as rhm has tried) unless I drop on some cheap cranks, but I may try 145 mm's next.

John