I was just wondering how much harder it is to ride on a smoothly graveled bike trail compared to riding on a blacktop road. I have never ridden a ‘century’, just 80 miles on a smoothly graveled rail-trail with a mountain bike with aggressive tire treads. Do you think this would be comparable to riding a ‘century’ with a road bike on equally level blacktop terrain? It seems to me you work significantly harder on gravel compared to blacktop.
Would a change to a less aggressive tire make a significant difference in my speed? Since I primarily ride on rail-trails with some road riding I bought a Cannondale mountain bike (for durability-5600 miles without a flat so far), though the trails I ride are pretty smooth. I would like to improve my speed, so I guess the tires would make the biggest change to my riding. I'm sure changing to a road bike to ride the trails would make a big difference, since the bike would be a lot lighter than what I have now. Can I get a reasonable increase in speed with just swapping tires?