Outdoor Research’s Ferrosi Pants would seem to fit the bill here. Elastic drawstring cuffs and the elastic drawcord tucks away nicely into a pocket on the inside of the pant leg. Very stretchy fabric, so good for biking. Super durable and abrasion resistant; OR’s Ferrosi line is designed with climbers in mind.
I bought a used pair of these pants about two years ago, and I’ve worn them extensively for both bike commuting to work and for backpacking. This pair is still going strong and I liked the pants so much that I got a second pair for Christmas this past December. My only complaint with the pants is that they are a little bit slow to dry due to the relatively high spandex content (14%). However, I this high spandex content gives them their durability and stretch, so I think it’s a decent trade-off for your intended purposes.