B&H Photo offers an enormous selection of photography and video equipment, big screen TVs, computers, etcs. Maybe the world’s best select in fact.
Cyclists can find gear like the GoPro helmet-cam and other cycling-appropriate items, like point-and-shoot cameras. Don’t forget a filter for your camera (if it accepts one) when used on a bicycle (mud, dirt protection).
What I shoot when riding
My favorite high quality camera for cycling is the Fuji X100, with its sibling the Fuji X10 also a good choice when a zoom and more compactness is needed. Smaller compacts might meet your needs, but my own photographic approach demands the higher quality.
I carry the X100 around my neck/shoulder with a strap shortened so that the camera is snugly in place just to the left of my right armpit. I can bang down mountain biking trails no problem like that, pop the strap over my should, and I”m ready to shoot.
See my numerous Views from a Bike, and Yosemite National Park — Olmstead Point to Tioga Pass.