From what we can tell, the Barack Obama campaign is the only one that mentions bicycling in their energy plan.
From L.A.'s Street Heat
“As president…Obama will build upon his efforts in the Senate to ensure that more Metropolitan Planning Organizations create policies to incentivize greater bicycle and pedestrian usage of roads and sidewalks, and he will also re-commit federal resources to public mass transportation projects across the country. Building more livable and sustainable communities will not only reduce the amount of time individuals spent commuting, but will also have significant benefits to air quality, public health and reducing greenhouse gas emissions.”
And Obama claims to support the Bike Commuter Benefits Act,
but he's not a cosponsor (Update: As pointed out in the comments, it turns out he is - of the Senate version. You can't trust anything you read on the internets. Stupid tubes.) Kucinich is of the House version. (Update: So is Ron Paul)
leads the Republican's by mentioning mentions he rides his bike to the grocery store.
Clinton and Edwards both state the goal of reducing vehicle miles, and Edwards rode in RAGBRAI.
D.C., Maryland and Virginia all hold their presidential primaries on Feb 12th, by which time it could all be over.