I'm just trying to get a feel for how much time I might drop after commuting for awhile. Currently, I'm 12 miles at 1 hour to work. Doing that every day I work will be tough, as I work 12 hour shifts. That won't leave much time in the day if I do it every day.

I know no one can tell me how much speed I might gain/time decrease, so I thought I'd ask you how you faired when you started commuting? I'm not in horrible shape, but I could be in much better shape for riding.

You'll get a little faster... dropping 10 minutes might be reasonable. Think of the time you won't have to spend at a gym, though (if that's something you might do to stay in shape), or the extra energy you might have (eventually) to accomplish more. In those ways, extra minutes on the bike are 'free'. And, if you're having fun on the bike (instead of getting frustrated in the car), time on the bike certainly isn't wasted. Maybe it means you get to enjoy more guilt-free junk food? Most regular bike commuters start for a utilitarian reason like getting in shape or saving money, but stay with it because it's fun (at least according to polls on bike forums!).

Here are some common ways people miss out on free speed: put slick tires (not knobbies) on the bike, keep them properly inflated, keep your chain lubed, and set you seat to the right height.

I would think 10 to 15 minutes.
Your gearing in the 48/11 could be fast.
Try standing and pedal in your high gearing can make you faster.
Drink a Coke Pepsi before leaving work.
It will give you energy you can feel.

I have slightly over 10km one way commute. I have a bad habit of getting very fat in the winter. I still commute most of the winter but it's only 28-35mins each way in winter conditions. It's about the only exercise I get in winter.

In spring I also start to "train." So I do "real" rides in the evenings and weekends in addition to my commute. I don't count my commute in my weekly training hours since it's such a short ride. I do 10-14 hours of "training" a week above and beyond my commute. The snow here is all gone and in my current condition my commute is now taking 22-25mins.

By mid-summer I will get that time down to 17-18mins for 10kms. One of my goals this summer is to do it in the low 16min range. Right now it's a challenge to average 25-28kph at a tempo pace, by mid-summer I can average 35-38kph at a tempo pace.

Trying to calculating commute time decrease attributed directly to better physical performance is slippery slope, for me it lead to being able to take faster but busier routes, and ride more confidently in traffic. Add to the fact of faster traffic, came the need for faster bicycles, decreasing even more time. Depending on which part of my commute I happen to be in, I gained 1 to 3 minutes a mile, and that calculation is based on using different routes, where in the beginning I was stopped and waiting to cross traffic more, to now where I'm out flowing along with it with far fewer stops.

My commute tripled about 8 months ago to around the same as yours, and Mondays were never a problem, but by Friday I was tired and 5-10 minutes slower. The only difference now is I can maintain my time through the week without getting increasingly tired. I don't set any time goals though - I'm just trying to enjoy my ride.

My times pick up as warmer weather comes. Less clothing, more aerodynamic, less stuff in my bag, conditioning improves etc.

Try new routes too. I found a new route to work and dropped 10 minutes - it is also flatter and has more open roads so I can see areas in which I can seriously improve speed. If your route has a lot of lights or roads on which you can't do 20mph+ then you may find it hard to cut down the time significantly.

Of course you can also incorporate training into your commute - intervals or similar.

Daven

I've gotten MUCH faster in the past 2 years of cycling - I've gone from average 19ish mph over 40k to pretty much 24mph over 40k (about an hour) of riding on a flat course, which is fast enough to hold your own against competitive road cyclists (whom I train with).

It doesn't seem to translate to too much speed bonus on my commutes, though. It would if I hammered it, but at my typical commute speeds, there is a far greater impact by the traffic and stoplights than there are with my riding. I might gain 10-20 seconds on a big hill if I go hard on it, but that's nothing compared to the 1 minute stoplights that I hit.

I don't hammer my commutes, so it doesn't really make a difference. (Unfortunately)

Depends on your bike and the weather. Even on the same bike I can just *feel* how much slower it gets below 35F. I almost don't look at my bike computer anymore because my times are so incredibly consistent. My 26" slick bike is 48-51 minutes in the warmer weather. My 700C 70's road bike is 36-45 minutes and my racing bike is 28-34 minutes. My route varies a little, but it's between 9.5 and 10 miles and I've been doing it for 2 years which includes winters.

It really depends as to what your commuting route is like and how fit you are already as to how much time you'll be able to chop off. I tried out a route for a possible new job which was about that distance, rolling country lanes so no stop lights and I got there in about half an hour

I managed to carve away 10 minutes from my commute over a year. Most of that was getting used to the route and finding short cuts, and a little bit of increasing my speed.

It really depends. On my short 3 mile commute I've shaved maybe a few minutes, but a lot of factors come into play. Mostly traffic conditions. Maybe drop a few pounds off yourself and/or your bike. Also different tires may help as well.

I got slower. Yep. When I first started riding for weight loss, and pushed as hard as I could. I no longer push as hard, so my average commute time has actually increased a bit.

My shortest distance round-trip is 33 miles. Sometimes I take a hillier 41-mile round-trip. Either way, my average speed now is slightly less than it was when I was 50 lbs heavier, but I enjoy it more.

When I started my commute took me a bit over an hour. Now, on a good day I can do it in 30minutes, 40 minutes normal. But it was a combination of getting stronger and optimizing my route. However, now, if the weather is nice, I detour to make my commute longer.

my commute sadly hasn't dropped much in duration, even though I have a better bike, SPD pedals, etc. main reason is that there are just too many intersections.

sitting at a stoplight for 2 minutes undoes lots of fast pedaling. sigh.

I've been commuting for years. The more I commute, the less I worry about how long it takes. I have arranged things so that I'll get there when I get there.

Not too many intersections for me. There are a couple lights on the first leg, but then I pick up the MUP for a good portion of the ride, and the last few miles are open highway(with a bike lane on the side). So it's not traffic or stopping that's giving me that time. But this is in the Denver area, so it is not flat, either. The last hill I have to climb into work is a beotch.

that's your time. it won't change. to change your time you'll have to change the machine you are using. my commutes actually got longer because I started to realized what an a-hole I was buzzing through traffic lights. now I ake longer but can live to tell about it. be careful! ;-)

1+ on that.

I am a year round commuter of 14 miles one way. In the winter my ride is about 1:15, and down to about 1:00 in the summer. Getting into shape, less constricting clothing, etc. contributes to the decrease, and I might add that riding in the more available daylight of summer allows me to go faster too.

I ride 8 miles one way. I can do it in about 30 minutes right now if I push a bit. Later in the year, I can get times down around 24-25 minutes. But a few years ago, it dawned on me...I'm riding into the office, a place I really don't care to be at....why would I want to push it to get there any quicker? So, now I just ride along and try to enjoy the ride and it usually takes about 35 minutes to get in.

I ride 10.5 miles one way, and in the summer my average time is 38 minutes, with my fastest 34.

My commute is about 15 km, varied terrain, a couple of hills, a couple stop signs, and on average I have to stop at 3 or 4 traffic lights. When I first started commuting last spring, it took about 50 minutes, and I got that down to about 42 minutes by the middle of summer. If I ride my cyclocross bike instead of my regular mountain bike commuter, I'm 5-10% faster. I think the biggest improvement over the year was on the hills. I know I got a little faster on the flats, but I really worked hard on improving my speed up the hills, and I think that's where much of my average speed gain came from.

My commute takes the same time no matter what, pretty much. The limiting factor has always been errands (kid drops) and traffic + lights.

I first started commuting in November 2008. For my first month, my 9 mile commute took me 64 minutes on average. I got a better bike, with better tires and the second month I'd dropped my average time to 45 minutes. A year and a third since I started, I've dropped that to 40 or 41 now.

The big difference for me was getting better tires/bike (I had knobbies and my breaks were always dragging), getting in better shape, and getting comfortable with the route (at first I stopped at all the stop signs, now I ride "in my own private Idaho" ). That cut 15-20 minutes off in a month.

If you and you're bike are in pretty good shape, you might not be able to improve that much, but I'm sure you can cut 5-10 minutes off.