I've been riding for a year. I didn't drop a pound until I went more than once a week.
After I read 'Younger Next Year' I decided I wasn't doing myself any favors by riding just on weekends. So, I got out there, without my husband. And I loved it. The minute I did, I started loosing inches. A couple of months and my husband said 'Please don't hit me, but your butt doesn't jiggle as much as it used to'. He tends to ride behind me. Even I like the way my butt looks!
I don't have a scale. But all my clothes fit looser. I've lost a couple of inches off my legs, two in my waist and 2 around the bust. I probably had 25 lbs of jiggly bits. Now they are muscle. I don't care about the pounds. Just the inches. Course, I've always eaten well. No fast food, I don't drink soda, eat very little dairy and buy mostly organic.
I just began mountain biking, last month. I definitely use more upper body for that. Glad I put 1,600 miles on my road bike first and I've been lifting those little 5 lb weights. We've got really rocky paths out here.