The wide angle version will accept a 2GB card and record 1 hr. There is a firmware update that can be done to the camera so that a 4GB card can be used. If you buy one, 1000mah rechargeables are a must. I have two sets of batteries, and keep them with the camera. Im very happy with mine.
Here is another mtn bike video with the GoPro Hero Wide. The camera has trouble with abrupt changes between light and darkness, but the firmware upgrade is supposed to improve that. YouTube - Juneau Alaska Mountain Bike Trail Ride