My chart doesn't work for these because they have an internal hub. Comes with three possible front chainrings. Their chart says with the standard, the low gear is 33.1" and the lowest is 35.7". Still not very low. (50 tooth or 44 tooth chainring) https://brompton.zendesk.com/hc/en-us/articles/360010452757-What-gearing-options-are-available-on-Bromptons-