If my math is correct 2" = 5 cm. I have had a 3 cm saddle to bar drop for some time, but just recently flipped my stem and now have a saddle to bar drop of 5 cm.

This seems fairly agressive, but I think I like it. Its only been 2 rides of 86 total miles (pretty chilly here in NY) but so far so good. I'm 44 yrs. old and not very flexible at all, so I'm surprised I like the increaed drop.

Can't even fathom going lower than 5 cm. Yikes.