Originally Posted by
cthenn
If that math is correct, that's actually fairly significant. "Significant" is a subjective term, but if you aren't just buying a new bike to commute to school or work, or tool around the neighborhood, then that actually is a lot. Also, you can't really take into account the performance of the bike, which certainly will have some additional effect.
I think that's a little high. I ran it on Kruezooter, assuming 8% grade (which would increase the difference, and assumed 300 watts. The results with those assumptions are 8 seconds a mile.
Meaningful difference in a race. On a 5 mile climb it might be the difference with staying in contact with the pack and not, but riding recreationally, hardly noticeable.
Also OP, are you sure about that 15.5lb weight. With pedals, it may not be quite as big of difference as you're thinking. Real world bike weights tend to be higher than advertised.