Originally Posted by
Doohickie
A mountain bike is too heavy for many commutes
What does "too heavy" mean in this context, anyways?
As I see it, the only situations where the weight of your bike really matters is 1) you're actually carrying it (up stairs, onto the train, putting it in your car, etc.) or 2) you're racing (where every fraction of a second counts.)
When you're carrying your bike, that part is obvious, and weight really matters. But when riding, it really only matters up hills -- and not very much. If you're 150 lbs and your bike is 20 lbs, you'll go up that steep hill only about 6% faster than if your bike was 30 lbs instead.
For a commute, it seems more important to have a bike that can do what you need it to -- carry your stuff if needed, jump up on curbs, handle broken pavement, etc. and not break than to have it be as light as possible. A mountain bike (or hybrid) especially with slick tires if it's mostly ridden on the road, often excels at this job.