Riding a hybrid your major barrier to increased speed is wind resistance, as an example:
The power needed to push an object through a fluid increases as the cube of the velocity. A car cruising on a highway at 50 mph (80 km/h) may require only 10
horsepower (7.5 kW) to overcome air drag, but that same car at 100 mph (160 km/h) requires 80 hp (60 kW). With a doubling of speed the drag (force) quadruples.
On a bike, once you're around 15mph, wind resistance becomes the major obstacle as so much more power is required from you for relatively small gains in average speed. So don't be disheartened, it takes a lot of ewffort now to start going faster and the easiest way is to become more aerodynamic! That's why racing cyclists wearslippy tight lycra, are hunhered down over the bars not sitting like a barn door to the wind and use narrow tyres which again offer much less wind resistance.
Don't beat youself up too much!
You can develop more power, the way to do this is ride intervals, short and hard periods followed by relaxation rather than just hammering the pedals at the same rate. The Swedes do 'Fartlek' training, where for example they will springt the next 1oo yards or half mile to the next junction/lampost/pub or other suitable land mark and then spin gently to another one and repeat. We do this when we ride as a group, faster and slower periods throughout the ride. Riding with others is also good for increasing speed too.
Keep it up, you'll get faster, but don't obsess about it!
