Originally Posted by 55/Rad
Going from 18 to 15.5 can feel semi-substantlal, particularly if the loss is in the area of rotational weight - wheels, tires, cranks, pedals etc. The biggest gain is in pure acceleration, particulary from a stop or a very low speed.
That said, it won't necessarily make you "faster" overall. I'd rather be cruising on an 18 pounder at 20-25 mph than on a 15. I'd also prefer the heavier bike on descents. But I'd rather have the 15 on a hillclimb, starting from a light or coming out of a turn.
The key is to finding a good balance. 18 is not heavy by any means and for me, is in the range being ideal.
55/Rad
What Rad said. I just dropped 14oz off my race wheel tire combo and yes I can really tell the difference. Bottom line is to lose 3+ lbs off your bike isn't going to be cheap, upwards of $1k for the same money you could probably hire a coach for most of 1 year and that
will make you a much faster rider.