Your weight, not the bike's. And what was your weight prior to commuting compared to your weight now?
I started commuting (4 mile one way) at the end of this June at 160lb. Now at 150lb. I've been an avid weekend hiker for the past decade, going usually around 10-12miles per hike and often 1-2 thousand feet elevation gain per hike, and my weight hadn't changed. I guess commuting 5-6x/week just burns more calories or boosts my metabolism more. I'm quite surprised. Well, with the weight loss I can add more accessories.

commuting has helped me a lot... I was at 248 earlier this year, am now at 230. I commute 2x weekly, 32miles round trip.

I attribute most of my weight loss to commuting. Started two years ago at 250 lbs. My commute strategy then was to cycle three miles from the house to the train station and then load the bike on the train for the rest of the trip to work.

Now I cycle the whole way to work and back, 25 miles each way, five days a week. I've been doing that since January 2011.

My weight now is 185 lbs and still dropping about a pound a month.

Before I commuted I weighed 125lbs. Been riding for 4 years and I now weigh 125lbs. I have a car now so my weight should increase pretty soon.

Too much. 356. Started commuting in June when I was 375ish. Started bicycling in may when I was 380ish. Commute 2x a week now, 19 miles each way, so nearly 80 miles a week. Trying to make the jump to 3x but I'm always too sore/exhausted to do the commute on consecutive days. Suppose I should HTFU.

Went from 160 to 155lbs. I'm a pretty skinny person. I think I just leaned out more

I was at 235 pounds before I started biking to work 4 years ago. I've been as low as 180 since, but right now I'm at 200. It seems that no matter the amount of exercise I do, my body figures out a way to put on weight if I don't watch what I eat too.

About 195 at the moment.
My weight ranges from 195 (summer) to 205 (late winter).
Most of my exercise comes from cutting a lot of firewood and commuting by bike. I really don't want/need to lose much weight and riding and wood cutting doesn't seem to do that. It does sure make a big difference in how it is arranged though.

Around mid-June I was at 232 lbs and things were getting out of control. My dad lost over 60 lbs by running & bicyling, so that motivated me to get with the program. I have always loved bicycles so I dusted off my old Hardrock and started cycling with him, doing 20-30 mile rides, plus did quite a few 10-15 milers solo to get my endurance up. Started commuting by bike (21 miles round trip) a few weeks ago, down to 215 lbs and setting a short-term goal of reaching 200 even

I went from 180ish to 165ish. Didn't have too much to lose.

I haven't lost any weight by bike commuting (16 miles round, 4/5 days a week), but it does keep me from gaining weight when I slack on extra riding.

I'm at 143lbs. I lost 36 pounds doing the P90X workout. I did notice, though, that if I bump up 3 or 4 pounds all I need to do is cycle hard for a week and a half. Then I easily drop a few pounds.

I am a skinny guy at 152 pounds and 6 foot tall, I used to weigh 165 but never more then that. Physical activity has always kept me from gaining a lot of weight.

215.....ish. from about 225...but I think I have gained muscle which has kind of put me at a standstill as far as the scale is concerned for now.

5'7", I weighed ~250lbs when I started commuting, and ~150lbs now

Now 166 pounds at 6' 0"". Max ever was 179 when I wasn't bike commuting as often. Also, I've given up a lot of sweets and eat healthier since then - more veggies, less meat.

I currently weigh 145 (5'10"). When I started commuting three years ago it was 130, less than I'd ever been as an adult. I gained a little too much over the winter and dropped about 10 pounds this summer.

That's impressive.

When I first started commuting I was 5'10 tall and weighed about 135 lbs. I am now 6' 3" tall and weigh 185 lbs. I was 15 when I started riding to my first job and I'm 56 now.

How has commuting by bike affected my weight?- I was a skinny kid and I'm a pretty lean adult.

win

Dang. Commuting hasn't made me any taller at all.

I currently weigh about 168, my lowest weight since college. I've lost about 30 lbs since Christmas, and cycling/bike commuting has played a big role. However, I had steadily gained weight for years, when I was also cycling a lot. I've managed to lose the weight by carefully tracking calories eaten and burned from exercising using a free on-line tracker called Lose It! Basically you enter in all of your personal data, set a goal for how much weight you want to lose over what time period, and LoseIt sets a calorie budget for you. The program automatically adjusts your budget lower as you lose weight because you need fewer calories. Long story short, I set my goal at losing 1 lb/week and have steadily lost weight at close to that rate since I started. I'm now in maintenance mode -- that is, simply trying to stay at my current weight.

I've been active most of my life, and it seems my "sweet spot" is about 185 (I'm 6'2) - appropriate balance with muscle mass and low body fat.

From '03-'06 several relocations took the momentum out of my active living routine (combined with stressful jobs with long hours) and I topped out at about 230.
For the past 4-5 years I've been bike commuting once again, and have been back to my 185 "prime" for a couple of years now. I'm now 45 and have noticed the changes in metabolism that come with each 5-10 year marker, and the beneficial effects that regular exercise can have on base metabolic rate.

I started at 210 and 5'9". Eventually landed at 150-155lbs.

Started at 280 or so. Down to 250>.

I played D1 basketball 30 years ago @ 220, so I think I MAYBE could lose 10 more pounds and that's about it!