have 700x35 Terra Speed on one bike (pictured)
they appear to run a bit 'small' - 700x35 might be closer to 700x33 *** (?) - so the 700x40 might be around 700x38 (?)
( *** installed on Maddux DC 3.0 hybrid rim with tubes )
The 700x35 Terra Speed (folding, black wall) weighs around 365 g ; the tread part of the tire is not as thick as I hoped - but so far so good
The tire rolls very well on hard surfaces - better than I anticipated given the low-profile knobs
did some dirt road and light trail riding - tire performed fairly well ... 700x40 would prob be better than the 700x35 for these applications