First Road bike

Rubystar
Rubystar Posts: 10
edited July 2014 in Road beginners
Hi

New to Bike Radar. Need some useful advice please on what to expect from a road bike. I am a middle aged man who is a recent convert to cycling. I have a Merida Crossway 100 Hybrid bike with Schwalbe Kevlar tyres. I spend about 70% of my riding time on-road and 30% off-road. I use it for fitness and losing weight, and also for getting around local bird watching. One aspect of cycling I find enjoyable is the gradual increase in average speed over a single ride that I am experiencing. The increase in fitness is allowing me to appreciate faster speeds over prolonged distances.
What I would like to know is - What will I notice on a road bike in terms of speed gain for the same or similar effort? As a newcomer to modern bikes, I look at the different types around and think - what actual differences are there between, say, a hybrid bike and a road bike when it comes to road use? What is it (apart from thin tyres) that allows greater speed? Understanding basic info like this will help me to evaluate road bike choice.

Thanks
Rubystar