The vast majority of energy on a bike goes to aero drag, and most of that is the rider. Are you in a more aero position on the Merida? That would fully account for it.
The difference in weight is not capable of causing much difference on flats, since it would just slightly increase rolling resistance. The differences in mechanical efficiency of well-tuned road bikes is also pretty negligible.
I'm curious what your new bike is. I currently have a 12 year old (but well maintained) Trek 1000. I'd like to get some better derailleurs (I'm constantly having to adjust and clean mine). But maybe I'll just get a better bike, I don't know.
EDIT: oh, you already said it: Merida Scultura
Re:Wooden bikes
by toomanybeersies on Wednesday November 21, 2018 @11:00PM
(#18507779)
I actually really liked my Trek 1000. I was very tempted at the time to just get a new groupset and wheels for the thing, but I had a really good deal on the Merida.
It's a very well built frame, it doesn't look the prettiest, but it gets the job done.
I had the same tyres, pedals, and shoes on my new bike (switched them over). I had a 3-4 km/h improvement on average on the flats instantly. So my new carbon bike was objectively better than my old aluminium bike.
I'm not sure if the improvement was because the bike was brand new, or because it was carbon and had higher end components, but it was definitely there.