Originally Posted by
merlinextraligh
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.
equals about 3%. Don't make it more complicated than it needs to be - the simple ratio of the difference over total weight.
Same speed, about 3% less power. Same power, about 3% more speed. At 8-10 mph the aero drag doesn't count for much.
If it's strictly about weight, that makes it pretty clear cut. If the cost of shedding 5.5 pounds is worth it for 3% extra power on the hill, then go for it.