Why are road bicycles so much faster than hybrids?
I commute in on a bog standard hybrid, and the guys on road bikes sail past me with what looks like minimum effort.
I understand thats what they are designed for but what exactly is it that makes them so much quicker?
Road bikes are faster due to their generally higher gearing and especially due to their narrower tires that pump to much higher pressures. Think of your bike like a boat. When you start a boat it gets up to speed and eventually is up on top of the water (what is called planing) and then you can actually reduce the throttle and mantain the same speed. In the same way narrow tire road bike riders can get their bikes up to speed and actually throttle back and keep the bike going at a similar tempo. The tires on a hybrid bike do not inflate to the 100-130 that many road bikes tires do. We used to have a pair of racing wheels and tires at my bike shop that we would let hybrid owners borrow. They could not believe the difference.
On the gearing side of things think of yourself as a racing car engine. Race car engines and the human body produce power in a very narrow power band. For the human body the RPM at the cranks is optimum at about 60-90RPM. If you slug away at the pedals at lower than 60RPM you can fatigue and injure yourself. If the spin the pedals above 90RPM it takes special training and techniques to prevent bouncing on the saddle. Track racer Rebecca Twigg could spin at 200RPM but that is definitely the exception. So if you ride a mountain or hybrid bike these usually are equipped with an extra front sprocket for hill climbing and have very wide gear ratios. The overall high gear on the hybrid bike may be lower because they have a smaller large front sprocket and a larger small rear sprocket. This would mean that on a steep downhill you may not be able to pedal any more and catch up with the road rider who can pedal away from you. Also, the wider ratios mean that when you shift up one gear your crank RPM may drop more that the 30RPM split between 60 and 90 RPM. This means it takes you a second to readjust the bike speed to get the crank RPM back in the comfortable range. So the idea gearing for flat land high speed running is one that has only small jumps between the gears. Racers will use gear clusters that have only 1-2 tooth changes between their gears. Those little incremental changes allow the road rider to just slip into a slightly higher gear and take the bike speed up by tiny increments until you see them ride off into the distance. This is while you are trying to catch up and battling the big ratio changes with your legs going from 40RPM to 100RPM and back to 70RPM.
Then last factor is you may be riding with riders who are in better shape and enjoy dropping hybrid riders. Let’s face it we all enjoy going fast and doing better than the next rider. Who knows maybe the rider that is passing you is riding 300 miles per week and you are riding 40 miles per week.
