Free motion stationary cycling, DIYed [Video]

Cycling workouts are difficult to actually execute when you're living in a highly urbanized area like downtown New York or Los Angeles, or on those dark, rainy days.  For those who don't feel like falling to the stationary bike as a last resort, there are these remarkable DIY-able free motion bicycle rollers.

At $35 in parts and apparently less than 4 hours or so to make, it looks to be something for the more venturesome, so YMMV, indeed.

[Instructables via Gizmodo]